Getting to Know the Arduino IDE

By Brandon Tsuge,


In this post, we will see how to install the Arduino software and use the integrated development environment (IDE). For this series, I’m going to be using parts from the Arduino Starter Kit


Windows Installation

First, go to Arduino software download page here. For windows users, click on the installer option. Mac users will only have one option.

Arduino Software Download Page

Download and run the executable file. Agree to the license agreement. On the next screen, make sure the “Install USB driver” box is checked and finish going through the installation.

Arduino Software Installation Wizard


Mac Installation

For the Mac installation, clicking on the link from the download page will download a zip file. Inside the zip file is the application file. You can run Arduino by clicking on this link directly from your downloads folder, or you can move it to your applications folder.

Arduino Software Download for Mac


Using the IDE

Open up the Arduino software. This will be the environment where all of the code will be written. If the interface is too small to read, you can change the scale by going to File>Preferences. You’ll have to close and reopen the software for to it to take effect.

Arduino Software Preferences

Arduino Preferences Menu

The icon with the check mark is the “Verify” icon. This icon will check the syntax of the code for any errors. The icon next to it is the “Upload” icon. This checks the syntax and then uploads the code to the board. The three icons to the left are “New,” “Open,” and “Save.” The last icon on the far right will open up the serial monitor, which will be discussed in later posts.

Arduino IDE Icons


Communicating with the Arduino Uno

Next we’re going to verify that your computer can communicate with your Arduino. Connect the USB cable to the Arduino and the computer. You should see an LED light up.

Arduino USB Cable

In the Arduino IDE, we’re going to open up an example to upload to the board. Go to File>Examples>Basics>Blink.

Arduino Blink Example

Then make sure you have the correct board selected by going to Tools>Board>Arduino Uno.

Arduino IDE Board Selection

A COM port needs to be selected in order to send and receive data. Select the port by going to Tools>Port. For the Arduino Uno, the COM port is usually labeled. For Windows, the ports are numbered. For a Mac, the port will have “usbmodem” in the name.

Arduino COM Port Selection for Windows

Arduino COM Port Selection for Mac

If you choose the wrong port, the IDE just won’t do anything. To get out of this, choose the correct port and upload again. You’ll initially get an error. Then just click upload one more time.

Arduino IDE Error Message

On Windows, you can check which port is associated with your Arduino by going to the device manager. Scroll down to ports, unplug your Arduino, and then reconnect it. You should be able to see a new COM port pop up. This is the one that is connected to your Arduino.

Windows Device Manager

The particular example that was uploaded turns Pin 13 on and off, over and over again. The “L” LED is connected to this pin and will blink if everything was done properly.

Arduino Uno Pin 13 LED

Now that you’re able to upload to your board, you’re all set to start building circuits and writing code.




Remote Control of a Brushed DC Motor

By Brandon Tsuge,


Introduction

In this post, we’ll learn how to assemble a brushed DC motor with a rotary encoder that is controlled by a radio transmitter. 

Here are the parts I used for this demonstration:

Pololu 50:1 Brushed DC Gear Motor (https://www.pololu.com/product/4753)

I’m not and affiliate for Pololu, but I still recommend this, as it is a quality motor with thorough documentation).

Arduino Nano: https://amzn.to/37z5OJE 

USB Cable for Nano: https://amzn.to/39MXSqW

DROK Dual DC Motor Driver: https://amzn.to/36LDx3y

Radiolink RC Transmitter and Receiver: https://amzn.to/3qvZsU6

Breadboard: https://amzn.to/3ge63xH

Jumper Wires: https://amzn.to/3owv6Pz

AA Battery Holder: https://amzn.to/36N3M9M

Glass Fuse Holder: https://amzn.to/37Fea2w 

Glass Fuses: https://amzn.to/37CUvQP

A typical brushed, direct current (DC) motor has two leads. When a voltage is applied across these two leads, the motor shaft spins. Reversing the polarity of this voltage will reverse the direction of rotation of the motor shaft. DC motors are usually wired to a motor driver, which receive and interpret control signals to ultimately drive the motor’s speed and direction. Brushed motors like this are considered to be open loop, meaning they aren’t capable of sending back information about its shaft position or speed.

Brushed DC Motor

This type of motor becomes closed loop when a rotary motor is attached. In this case, the motor is driven in the same way as any other brushed motor. The only difference is that there is now the ability to measure the motor shaft position. Usually this type of motor will have 5 or 6 wires. 

Brushed DC Gear Motor with Rotary Encoder

Two of the wires are used for the motor power and the other wires are used for the encoder. Essentially the encoder works by turning a signal on and off as the motor shaft rotates. These pulses are directly related to the motor shaft position. I like to use the analogy of a playing card flapping in the spokes of a bicycle wheel. The faster the wheel moves, the more times you hear the playing card making a noise. In the case of a rotary encoder, a high number of pulses over a given time period indicates a faster motors speed.

For this example I will be using a Pololu DC brushed motor with a 50:1 gear ratio and a rotary encoder with two outputs. It has red and green wires to power the motor shaft movement. It has a green wire for a ground for the encoder, a blue wire (Vcc) to receive a positive voltage between 3.5V and 20V, and a yellow and white wire to output separate encoder signals.

Rotary Encoder Wiring




Below is what the output signals would look like as the motor rotates. Notice how they are out of phase. The signals alternate between values of the supplied Vcc and 0V throughout the motor rotation. For this encoder, if you count the rising and falling edges of a single output, you will count 32 counts per revolution. If you count rising and falling edges for both outputs, you will count 64 counts per revolution. Since this is a 50:1 geared motor, a single rotation of the output shaft will result in a total of 3200 counts (50 x 64 counts).

Rotary Encoder Output — Forward direction

The order in which the rising edge of a particular signal is read is an indication of direction. For instance, let’s say that when the motor is rotating clockwise, the rising edge of Output B is counted before the rising edge of Output A. If that was reversed, the rising edge of Output A is counted first, indicating that the motor is rotating counterclockwise.

Rotary Encoder Output — Reversed Direction

An Arduino Nano is being used to power the motor encoder and read the output values of the encoder. It is also sending signals to a dual motor driver to control the speed of the motor.

I’m also using an RC transmitter and receiver to send signals to the Arduino. Essentially, moving a stick on the controller transmits a signal to the RC receiver. The receiver sends a signal to the Arduino which interprets it and sends it to the motor driver. The motor driver receives the signal from the Arduino, interprets it and outputs power to the motor. All of these signals are pulse width modulated signals, which I will discuss in another post. Lastly, as the motor rotates, the Arduino reads the encoder values.

Hardware for Remote Control of a Motor


Wiring

To start this example, I place an Arduino Nano in a breadboard. I use wire jumpers to make connections to the components. The red and black wires on the motor are wired to one of the black sets of screw terminal blocks on the motor controller. The green wire is connected the Arduino ground and the Blue wire is connected to the Arduino 5V output. The yellow and white wires are attached to pins 2 and 3 on the Arduino.

Electronic Assembly of Nano and Motor-Encoder

For the motor driver, the tan screw terminal blocks receive power from an external power source between 6.5V and 27V. I’m using a AA battery holder and a set of 8 AA batteries for this example. The user manual for this board recommends putting a 10A fuse in between one of the leads of the motors and the motor driver and a 15A fuse between the positive end of the power source and the motor driver.

The motor driver also has a set of male header pins. These pins are what control the behaviors of the attached motors. If you look at these two pins, there are two columns. The left column is for one motor and the right column is for the other. The top pins are connected to 5V from the Arduino and the bottom pins are connected to a ground, also on the Arduino. The pins labeled ENA receive a PWM signal from the Arduino and are directly related to the motor speed. These can be connected to any Arduino pin capable of a PWM output. The pins labeled IN1, IN2, IN3, and IN4 control the direction of the motor. If IN1 has a value of 1 and IN2 has a value of 0, one of the motors will spin forward. If you reverse this configuration, the motor changes direction. This applies to the other motor output with IN3 and IN4. These pins can be connected to any digital pin on the Arduino

Dual Motor Driver Board

Lastly, I used and RC transmitter and receiver to indirectly control the motor speed. I chose to use Channel 3, which is the up and down movement on the left stick. I chose this channel because it is not spring loaded and will not return to the center position. The top pin connects to any digital pin on the Arduino, the middle pin is connected to 5V and the bottom pin is connected to ground.


Radio Control Receiver

Below is the diagram of the breadboard view.

Motor and Receiver System Wiring Diagram


Arduino Code

Setup: In this example I use 6 different digital pins. I set the pin leading from RC receiver to be an Input. The pins leading to the ENA, IN1, and IN2 pins on the motor driver are set to be digital outputs, and the pins connected to the rotary encoder outputs are set to “INPUT_PULLUP.”

I also use the “attachInterrupt” command to interrupt the loop and increment counting functions every time encoder outputs a “CHANGE.” Essentially I am counting the rising and falling edges of each of the encoder outputs. This can only be used with pins 2 and 3 on the Arduino Uno and Nano. If a second motor is needed, one encoder output on each motor will not be used. One encoder output per motor is often enough for most projects.

Loop: I start the loop be reading the RC PWM value using the “pulseIn” command. I write IN1 to “HIGH” and IN2 to “LOW” to establish a motor direction. I then use “if” statements to store the minimum and maximum values that are read from the RC receiver. I use this range to map the current RC PWM value to values between 0 and 255, since this is the range that “analogWrite” uses. This value is then sent to the ENA Pin to ultimately spin the motor.

Lastly, I print the counters.

Functions: I use two functions that simply increment two different variables. These functions are called every time the interrupts are initiated. 

You should now be able to control the speed of the motor with the channel 3 joystick on the remote control. 

Here’s where you can find a copy of my code here.

Motor Control Demo

Also, note that when you open of the serial monitor, the counters are increasing as the motor spins. 

I hope this tutorial was informative.

The parts for this post were sponsored by Mechanical Design 101.


How To Get Started With Robotics At Home

By Brandon Tsuge,

If you’ve ever wanted to get started with DIY robotics, you’ve probably heard the name Arduino thrown around. Arduino is an Italian made, open-source, electronics platform with incredibly user friendly hardware and software. The modular nature of the hardware and the simplicity of the programming environment makes it ideal for beginners while still having the capabilities for more complex projects.

Most of the time when somebody says they are “using an Arduino,” they most likely mean they are using the Arduino Uno or Arduino Nano.


Arduino Nano and Arduino Uno


Arduino Uno

Arduino Nano

In simple terms, the Arduino is a mini computer that can perceive the environment through sensors that measure things like light, sound, temperature, distance, etc. It can then use this information to impart change to the physical environment by sending signals to actuators or other hardware. Actuators consist of things like motors, lights, speakers, LCD screens, and much more. The Arduino performs these actions through instructions received in a program, or sketch. These sketches are sent via a USB cable and created using the Arduino integrated development environment (IDE), which is based on the C programming language.


Arduino Communication Diagram


In a nutshell, here are some of the main features of the Arduino:

· Read an analog signal

· Write an analog signal*

· Read a digital signal

· Write a digital signal

· Provide a 5V or 3.3V source

· Provide a ground (0V)

· Easily communicate with your PC via USB

*Arduino can’t truly create an analog signal. It “fakes” it by using pulse width modulation (PWM). I’ll elaborate on this in a future post.

If you are a complete beginner to programming and electrical circuits, I recommend getting the Arduino starter kit (https://amzn.to/2YWt01o). This set comes with over 100 components and an easy to understand project book that teaches fundamental concepts via sample projects. In the upcoming posts, I will be providing tutorials on each of these examples from this book.


Exponential Threat, Part 2

By Chris McCarthy,

Ambassador Trong walks onto the bridge of Amanda’s ship. His attaches, Liam and Sturgis, enter with him. 

His pageant guard Maritha, walks just in front of him waving green and yellow flags wherever he is going to walk to give him the pageantry accorded to his station.

The entourage walks onto the bridge in a heightened dramatic way, stone faced and eyes not connecting with anyone. Liam and Sturgis do dramatic bows and Maritha walks around the bridge, waving her flags, as Ambassador Trong empties his pockets of the thick stack of unusable paper credits and gold statues of his predecessors. In the old days. He might have left one of these valuable statues with the ship, but inflation’s a bitch and these days the statues are just used in the ornate display of wealth and privilege that got the man into this position.

Amanda’s crew stand at attention in a line at the center of the bridge, Amanda standing directly on top of the four foot diameter Intergalactic Legion insignia, her fists up in the official pugilistic stance of a captain, the rest of the crew standing in official positions behind her, Salamander—his official title Number Two—with his arms on his hips looking up and to the right, affecting an ambitious overconfidence; Lisa, her hands on either cheek, her face locked into a silent primal scream, an affected stance all Navigation Specialists must use, the meaning lost over the centuries. Winston, the communications officer, is down on one knee, his arms out to the side as if he’s singing the final note in the final song of act two of a musical, his mouth wide open to affect a basic level understanding that his job is in communication, which typically for humans involves the mouth… ok, you get it. 

“Sup?” Suddenly, Ambassador Trong, relaxes his body and drops all formality. “What the fuck is up, Mandy?” He looks around the ship, taking in the small bridge. 

Amanda softens a bit, but keeps her official stance. Her crew behind her stay frozen but keep their eyes on her, following her cue. 

“What, you don’t want to talk to your old buddy, Edwin Trong?” He asks coyly. 

Amanda shows the beginning of an uncomfortable smile, still frozen in position. Edwin walks up and pretends to shadow box with Amanda. 

Lisa, her mouth still locked in the mock primal scream, meets Winston’s eyes below her and to the right, “Can we stop doing this now? I’m getting crow’s feet.”

Winston whispers, “We have to wait for Ambassador fuck face to say at ease…”

Trong takes in Amanda’s crew. “There’s a real ragtag underdog thing going on here. Very on-brand, Amanda. The self-sabotage is palpable… but that’s always been your thing, hasn’t it?”

He looks to his entourage who suddenly remember to laugh uproariously. Even Maritha stops waving her flags around and cracks up. 

WHOOOOSH.


Exponential Threat, Part 2
Exponential Threat, Part 2, Graphics by Chris McCarthy with Imagen3

The loud noise of a toilet distracts everyone as the automatic hatch slides open from a hallway at the back of the bridge and Chase walks onto the bridge. Trong’s retinue look over, Liam wide-eyed at the impertinence and Sturgis looking at Trong and Liam, wondering how he should react to this breach in protocol.

“Excuse me, sir, what do you think you’re doing?” Sturgis asks, a condescending lilt to his voice. “Trong is eldest son of one of the wealthiest asteroid mining families, so you will show him the respect he’s earned…”

Sturgis stops talking as Chase rips open a bag of Prathian Figs and throws one in his mouth. “These are supposed to help get you regular. Oh shit, wait, that’s prunes, right? Too bad Earth is gone and no one thought to take prune trees with them when they left.”

Then for the first time, Chase looks over at Ambassador Trong’s delegation. 

“Sorry, guys. I had to see a guy about a prairie dog back there. Right? Get it?” 

He walks over to Sturgis and wipes his hand off on his shirt then looks at it to make sure it’s clean. “Oh, I’m just fucking with you guys.” 

Sturgis’ mouth falls open. 

Amanda looks over at Chase nervously, “Dad…I mean Chase…who the hell are you doing?”  

The rest of Amanda’s crew, visibly exhausted now and wearing pained faces, look around at each other desperately as they try to hold their positions. 

Trong says, “Excuse me. You will give me the deference I have earned…” 

Maritha runs over waving her ribbon in Chase’s face—this time it’s an aggressive move. She hisses loudly at him. HISSSSSS. 

“OK, so they don’t have gum on Tumis,” Chase says. “Noted. I’ll let my smuggler friends know.” 

Chase looks at the stone-faced entourage. “I’m kidding. Come on, have a sense of humor.” 

Suddenly, a look of realization comes over Trong’s face. “Wait a minute…” says Trong. 

Maritha keeps waving the flags as she circles Chase, who doesn’t seem to notice. 

“Maritha, stop. Just please stop.” Trong says, pushing her flags away.

Maritha dances her way to the other side of the ship.

The crew, still frozen in place, look at each other as they mouth her name—Maritha.

Salamander says, “It has to be Marissa, right?”

Winston nods in agreement, “Has to be. The thhhh sound is really uncomfortable.” 

Trong walks up to Chase, excited, “You’re Chase Markley!” 

Chase throws another fig into his mouth then puts the empty sack into Liam’s pocket. “Yep, who the fuck are you and why are standing on my bridge?”

Trong steps back so Chase can see him better. “It’s Edwin Trong. You used to drive me to school when Mandy and I were in pre-academy.”

“Oh, yeah, Edwin. OK, how’s your mom doing?” 

“Oh… she’s dead.” 

“Oh really? Shit. Wow. She’s dead? Like fully dead?” Chase asks. 

“Yeah, like fully dead. Yes.” Edwin responds.  

Amanda rolls her eyes as Chase walks past Edwin over to her and the crew. “Why are you so uptight Mandy?”  

He touches her shoulder and gently shakes her and she unfreezes. 

The rest of the crew relax out of their poses. Lisa rubs her cheekbones and flexes her jaw. “It feels like I’ve been chewing gum for an hour.” 

“Gum’s illegal here. Just ask… Marissa, is it? I mean her breath could knock a buzzard off a shit wagon.” Chase says. 

Marissa looks over and hisses again but lowers her flags to her side when she notices Edwin laughing, quickly followed by Liam and Sturgis. 

Winston stands up, rubbing his knee. “Gonna need to oil this knee when we get to the outpost. Wait a minute…” 

Winston looks down surprised as his knee emits a faint blue glow.

Lisa raises her eyebrows. “What’s happening to your knee?

Winston pulls up his right sleeve and examines a small screen on his wrist. “It appears that the update included a patch to my regeneration algorithm. The nanobots in my system were reprogrammed for better efficiency.”

“Wow,” says Lisa. 

Chase looks at the crew, now relaxing back to their normal postures, except for Salamander. “Hey crew, relax. Chill. It’s just old Edwin Trong. Used to drive him to school then mow his mom’s lawn on my way back home.”

Chase shakes Salamander gently. “You can relax now.” 

Salamander wakes up, shivering. “Sorry, I went deep there.” He runs over to a corner of the bridge and taps a button. A stream of hot air comes out of a panel in the wall. “Oh yeah, that’s the stuff.” 

“Sorry, what did you say, Chase? Mow my mom’s lawn?” Edwin asks. 

Chase says, “It’s an expression.” 

“OK. That’s what I was wondering.” Edwin asks, slightly suspicious.

“I mean, I actually did mow the lawn…I did it well. Really well. Too well, maybe.” Chase says. 

“Oh. OK.” Edwin shakes off his confusion and it’s quickly replaced by excitement.

“Well, guys” Edwin says, “This is the legendary bounty hunter, Chase Markley. He brought down the Orphelian six.” 

“Seven. One of them morphed into two.” Chase says. 

Winston leans over to Salamander, and whispers, “Notice how one always morphs at the last minute. Champion stat padder, this guy.”

Sal says, “What are you talking about? Chase is a legend. Plus, he’s Amanda’s dad, so… ” 

“You’re obsessed with Amanda.” Winston counters. 

Salamander looks at her, admiringly, “She’s a good leader. Just doesn’t always know how to show it.” 

“She shoots you out the airlock every chance she gets,” Winston says.

Winston watches as Lisa walks over to Chase and puts a hand on his bicep.

Lisa says, “Chase, thanks. Finally someone did something.” 

“No problem, Lisa. Edwin’s just a family friend.” 

Amanda steps between Edwin and Chase. “So now that we’re done with all that, let’s talk about…”

Chase interrupts. He looks at Edwin, an edge to his voice. 

“So you weren’t going to at ease my very hospitable crew who were here all ready for your arrival. I mean, shit, ancient metal face over here got on one knee for you. You know how much effort that took?” Chase points at Winston. “The guy’s three hundred years old.” 

Winston glares at Chase, then looks down at his knee. He stretches it out. It feels amazing. 

Edwin puffs his chest out with pride. “Well, as you of course know, I am trade ambassador for Andolenga Outpost, a position my family has held for two hundred years. It is my duty and privilege to choose one ship a day to extract ceremonial tariff. So when I saw captain Amanda Markley’s identification come up, well, I mean, I had to stop her ship. Just for old time’s sake.” 

“For old time’s sake?” Amanda says. “I know you hate me for what I did. What do you want?” 

Chase shoots Amanda a look, “Amanda, I got this…” 

“No, Chase… I got this. Edwin, tell us our payment and we’ll be on our way. You’ve lorded yourself over me and my crew enough.” 

Edwin laughs. “Now why would I hate you Amanda?” He walks toward the front of the bridge and looks out the viewport at the blue planet that gets larger and larger as the ship approaches. 

He turns on his heels and looks back at her. “Because you came between me and my sister? Is that a reason to hate someone? I don’t know…” 

Chase tries to intercede. “Guys, let’s not get carried away here…” 

“Silence!” Edwin says. 

Liam pulls out a six inch blue light chryo-blade and waves it in front of his face, the blade humming as it slices the air. A second prior Liam seemed like nothing more than a fop courtier, but now he takes a well-practiced fighting stance.

Amanda looks around the bridge. She realizes she needs to take control. “Edwin, let’s…”

“Did you not hear what I said?!” Edwin screams. He waits a moment then looks around the bridge, everyone now silent. He sits down in the captain’s chair and picks at a hangnail. “Good. As I was saying… getting between me and my sister probably wouldn’t be enough for me to hate you. I mean, we were in academy. We were young.”

“That’s what I was thinking,” Amanda says. “Now let’s…” 

“But getting between me and my sister, whose heart you went on to break when you left her stranded after eloping with her.” Edwin says. 

Amanda takes a step back, “Uh, ok, see… what happened was…”

Edwin continues, “A heart break that quickly turned into rage for me after you told her you were breaking up with her because you had feelings for me, which was a lie…”

“It was, uh, the first thing that came to mind,” Amanda says. 

Lisa looks on and raises her eyebrows, “Wow.” 

“Yeah,” Chase says, nodding. 

Edwin continues on, “Edwina’s rage of course took our family down the pathway of internecine warfare, splitting our army into two factions, one that supported her as the successor of my family’s asteroid mines and the other, which supported me, splitting our power down the middle—and putting me in this embarrassing position as trade ambassador instead of Emperor of Planet Crassus.” 

Amanda cracks a sheepish smile. “Right. Totally. You have every right to be…” 

“Not that my sister fared any better. She fell in with a crew of Earth-wheat smugglers in the Daytona System and is now locked away in a prison half a galaxy away. Quite a fall from grace.”

“Yikes. Well…I would like to apologize…” Amanda responds. 

Edwin stands up and walks toward Amanda, “In other words, you destroyed my family, caused an internal division and power vacuum. A vacuum the Kreinalld family, our nemesis for centuries, stepped into, taking all of our power, now lording over Planet Crassus, our ancestral world.” 

Chase takes a step toward Amanda and Edwin at the center of the bridge, careful to avoid Liam’s glowing blade. “What can we do to make this right, Edwin?” 

“Make this right?” Edwin says, smiling. “Well, you’ve created the perfect scenario for me to justly kill you and your whole crew, right here on the bridge of your ship.”

Edwin nods to his right. Sturgis takes a step toward the center of the bridge and says, “You’re harboring a three month old mango-puppy, an animal blacklisted for trade. This is an infraction punishable by death on planet Tumis.”

“So, Chase and Amanda, I guess you could say you’re making this right.” Edwin says darkly.

Sturgis’ eyes turn bright green and he stares down Chase and the crew menacingly. 

Salamander walks over from the corner and stands next to Winston. “Did his eyes just change color?”

“Yeah. He’s like me. Just a later edition.” Winston says. 

“A later edition?” Salamander asks. 

“Yeah,” Winston says gulping. “He’s what we affectionately call… an armybot.”

“An armybot? As in…he’s like a full army by himself?”

Winston shakes his head, “ No. As in he murders entire armies…with his mind.”

“Oh sweet holy fuck. We’re going to die… like right now.” Salamander says, putting his hand to his neck. 

“Yep,” says Winston. He double takes as he notices a blue glow emitting from his right hand. 


Copyright Chris McCarthy and MDA Press 2024, Graphics by Chris McCarthy with Imagen3

Red Lines, Part 2

By Chris McCarthy


They met randomly at a movie theater. They had both gone alone to a Thursday midday screening of Michael Keaton’s comeback film and critical darling, Birdman. Celia was not at all fazed by going to the theater alone. She had the afternoon off and decided to go see the movie. No overthinking. No worrying about what it would be like going to the movie alone. She did it all the time. For him, it was different. He agonized over the decision. What did going to the movie in the middle of the day mean about him? Did it mean he was lazy? Unproductive? Did it make him a loser? Could he afford it? He really should be tidying up the resume and getting himself out there, but also he really deserved to relax. Once he decided that, yes, he would be seeing the movie today, or at least at this point it was a distinct possibility, he then wondered what it would feel like going alone. Would the cashier look at him strangely? Would he see anyone he knows and what would they think of him. None of this was in his control, but he thought it was in some way, which years later, he would realize was a problem and the reason for a lot of the things that went wrong in his life.

Celia had sat three seats down from Leo and, in the middle of a preview for Billy Elliot: The Musical, she leaned over and said with a half smile and a glint in her brown eyes, “I don’t think I’ll be seeing that one. I don’t do musicals in theaters. Maybe live, but not in theaters.” Leo laughed politely and said, “Same. Not my cup to tea.” They both leaned back in their seats, Celia, a hair of a moment later, after realizing the sudden lull would be a long one, as Leo repeated the phrase “Not my cup of tea” in his head a few more times, reliving each time how stupid it had felt coming out of his mouth—then Celia leaned forward and to the right, around the armrest, and asked Leo if he wanted half of her popcorn. 

She’d purchased the largest size and had the wherewithal to get a brown cardboard tray from the concessions person, as if she’d been planning from the start to share it with someone. Leo noticed the effortless way she did things for people. There was no overthinking involved. She just did it. Generosity was a part of who she was, but he also immediately knew that she never told herself she was generous or basked in it. Leo remembered thinking at the time that everything he did seemed to be done in the hope of some result. As if he was acting for an audience that would either clap for him or yell at him in approbation. Every detail and outcome considered. 

Celia moved to the seat next to him to divvy up the popcorn, then sat back, threw a handful of popcorn in her mouth and stayed there for the full movie. Walking out during the credits, Leo was amazed to hear his lips mouth the words, “Well, I owe you for the popcorn. How about dinner sometime?” He hadn’t even thought the words, hadn’t played with them in his mind a few times to get them right—they just came out. What was this amazing woman pulling out of him? The strength and confidence and comfort she gave him. He noticed her slim waist and the way her coat fit her shoulders perfectly as she turned toward him and held her hand out for his phone. 

Three days later, Leo and Celia went to dinner at one of Leo’s favorite restaurants, an Italian place called Dina’s, where the pair took over an overstuffed red booth for almost two and a half hours. Leo knew the waitstaff wasn’t rushing them to turn the table because of her—she had something about her that made people blur the rules. She was either unaware of it or at least never traded on it, which in a full circle way is why she had that way about her in the first place. 

That night at dinner the time disappeared even as Leo clung to every slippery minute. The highlight of the night was Leo’s hospital visit. When dessert came out, the waiter dropped one of the two forks on the floor and promised to bring another one right away. After three minutes of watching the desert instead of eating it, Leo went to the kitchen to ask for a fork. He ran into a busboy, who set his tub of dishes down, and quickly ran behind the steel pickup window to pull a fork out of a plastic tray. 

Three bites into the dessert, Leo started to feel a tightness in his chest. Then a tingling in his tongue and lips. His breathing became labored as red started to cloud the edges of his vision and the wooziness set in. Celia called 911 instantly. Instead of the warm August evening stroll with a possible stop at his Venice Boulevard apartment that Leo hoped for—his roommate Todd had been given instructions to shut the fuck up and stay in his room playing Call of Duty if he heard Leo come home with a companion—the date ended with Leo being rolled out on a gurney at high speed by two EMTs. He was administered epinephrine immediately and his anaphylactic shock almost immediately subsided. His breathing went back to normal and he felt the swelling around his eyes and mouth start to release. Still, his symptoms were so bad that the EMTs insisted on taking him to the ER for further observation.

Turns out the busboy had handled a plate with oysters moments before getting the fork for Leo and some shellfish oil was on his black rubber gloves. The ER doctor said it was not unusual for shellfish allergies to suddenly appear in adults in their thirties. 

From that night on, Celia kept an epipen in her purse just in case. And from that night on, Leo was in love. Celia hadn’t balked once in the way she looked at him in his utter emasculation, hadn’t betrayed a moment of embarrassment or desire to be anywhere but there, him lying on the floor barely breathing in front of their booth in his former favorite Italian restaurant, half a tiramisu spread on his chin and black button-up shirt.  

Loyalty was a big thing with Leo. 


Red Lines Ep 2
Red Lines Ep 2

Leo sits back in his seat in the back of the cruiser, his hands covering his face, not even crying but tears streaming. He takes a quick glance out the window before covering his eyes, mouth and nose again with his hands, then takes them away. He processes the reality of the situation. 

The cop catches Leo’s state in the rear view mirror. He’s been talking for a few minutes, but Leo’s only caught words and phrases. He can’t hear anything or isn’t ready to.

“What you did is help that woman and all the other people that man would have hurt should he have continued breathing.” The cop continues.

Leo takes this in and hears the voice in his head tell him this is all real. Too real. He says, “So, listen… You can just drop me off here. Anywhere. I’ll Uber home. I promise I will never say a word about any of this.” 

“I can’t do that,” the cops says, nodding his head left to right. “We need to make sure you’re one hundred percent clear of the incident. An associate of mine has already cleared the scene for any video footage, including Tesla or Ring cameras. He’s even checking the local neighborhood north of the shopping center for any lookie-loos. It’s for your benefit. Once we decide you’re clear and have planted a plausible story with our middle man who will convey it to LAPD—who will be very receptive by the way, no one’s gonna miss that fuck, death by brick is an occupational hazard for his kind—then and only then can we talk about your options.”

Leo’s head spins. 

“Options? When you said we were going to get the rest of them, what did you—?” Leo asks. 

“I have nowhere to stash you where you’ll be safe so I need to keep you close. And we need to get to the next place as soon as possible.” The cop says nothing more as he speeds the car up and changes lanes. 

Once off the freeway, they drive for another twenty minutes, winding through suburban neighborhoods and small commercial spaces in the city of Santa Ana. 

The house is at the end of Lyon street. Between the house and the backside of the power substation beyond it, sits an empty dirt lot strewn about with old clothes, a dilapidated Wolkswagen Bug, and countless trash bags. 

On one side of the street is a small Cuban restaurant that looks to be shuttered for good, a liquor store, and a low-slung flat-roofed two story apartment building with a parking lot on the street side of the building like a cheap motel. Every visible apartment window is barred. The cop pulls up to an open spot at the curb, just outside the spray of light from the lone streetlight on the dark street. It seems brazen to park just across the street Leo thinks. 

“We’re waiting on one other guy,” the cop says, emptying the final two pills from a prescription bottle into his mouth. He checks his watch and looks in the passenger side mirror. 

Seconds later, the passenger side door pops open and a short man with a paunch slides into the seat. The cop looks over then turns his chin toward the back seat.

“You just sit in the car and wait. But you see anything weird, text me. I’ll see it right here on my watch,” the cop says pointing at his wrist.

“Weird, like what? What do you mean?” Leo asks. 

“I wish I had more time to explain, but we gotta go. You’ll be fine here. Cam, you ready?” The cop asks, pulling his gun out from under the seat. 

“How long… how long are you going to be?” Leo asks. 

The man next to the cop nods and checks something in his waistband that Leo imagines is a gun. The cop opens the door and slips around to the front of the car in what seems like one fluid motion. Seconds later, the cop is creeping along the left side of the house, having stayed completely out of any splashes of light coming from the house. Leo barely saw him get there. The guy with the paunch is on the right side of the house, peeking into a window. He didn’t even hear the second man exit the vehicle. 

Then suddenly both men are gone, slipped into shadows. 

Leo stares at the house, fully alert, desperate for a noise, anything that will help him understand more about the situation and his safety. Behind the bars on the windows, Leo can see thin lace curtains—whoever is inside hasn’t been there long enough to think about covering the windows better. They’re on the move, not here for long, he understands. 

It’s seconds later that Leo sees the gunshots light up the windows—Bang Bang. Two shots. Two light flashes. He freezes, white-knuckling the armrest with one hand. What should he do? Any inkling that this is part of the plan dies when something happens on the right side of the home—Leo hadn’t noticed a door there, but his mind quickly establishes that there is an entrance from the side yard into the house, possibly into the kitchen. And it must be where Cam entered the house. Now the light from inside spills out through the open door and, through missing slats in the wooden fence, Leo sees Cam hurtling out the door and landing against several plastic trash cans, sending them flying like bowling pins. One opens up, dumping trash onto the lawn. Leo looks around the quiet street. It’s still. No one is around. 

An alarm in Leo’s head sounds: Get out of here! It’s time! He pulls on the door handle. It pulls easily but there’s no tension. It doesn’t engage. He can’t get out of the car. 

Looking out the window as he pulls on the door handle, Leo watches Cam pull himself against the side of the house. Then he sticks his head through the slats and looks directly at the car, nodding violently, trying to communicate something. What is he trying to say?

By now, Leo has moved onto the other door, the one that faces the fenced-in industrial lot to the left of the car. This door is locked too. Leo remembers something about the back doors of police cars only being opened from outside the car. Cam is nodding even more violently now and sticks an arm past his head through one of the open slats of the fence, looking like missing teeth, and gestures toward the house. Then Leo sees his body move violently, unnaturally in its prone position. He’s being dragged into the house.

Bang bang. The windows light up twice again. 

Leo’s heart pounds in his ears. Without thinking, he squeezes himself through the opening in the plastic divide between the front and back seats and lands uncomfortably with his head in the footwell of the passenger seat, his back hitting hard against the front console and the empty shotgun holder. In the footwell under the passenger seat, lodged into a plastic holder, he sees a pistol. He’s never been this close to a gun. He rights himself and slides over to the driver’s seat. From there he reaches back over and slides the gun out. He opens the driver’s side door and steps out. Halfway through closing the door, he looks through the windows and sees a man step out the front door, look left and right, then duck back inside leaving the door open. Thoughts fly through his mind as he pushes the door closed and makes himself small on the far side of the car. His breathing intensifies as he looks down at the gun and slides the safety off. A kid could do this, he thinks. 

Leo peaks an eye up through the car and sees the man has again walked back out the door and is now a few steps into the yard, looking in the direction of the car. He can’t tell if he sees the car, tucked away as it is in the darkness, then the man walks quickly over to the side yard before again surveying the dark street. 

Leo jogs away from the car, staying low behind the other cars parked along the curb of the street. He’d turn and run the opposite direction of the house, but he can’t climb a fence with the man on the lawn looking in the general direction of the car. The noise would certainly make his presence known. Leo follows the pathway of the de facto cul-de-sac toward the back of the power substation, then slips into the trash-strewn lot abutting the house. Stopping a few feet into the lot, he tucks the gun in the back of his waistband, naturally, since it seems like the only place that makes sense. All the while, sure to keep out of sight of the man on the lawn. He thinks he can climb the fence at the back of the lot and go… somewhere other than here. 

He runs through the lot, dodging trash bags and old car parts, then trips over an old tree stump, landing hard on his knees. The pain shoots through the midpoint of his shin where he made contact. He instinctively slides back to his butt and reaches both hands around the shin to assess the damage. Other than a cascade of blood and sharp pain, it’s not that bad. He steels himself to get back up and keep running, then turns to his head and looks right through an open space in the overgrown ivy on the chainlink fence separating the lot and the house next to it. 

There, less than ten feet away from him, sitting against the side of the house is the cop, the top of his black shirt soaked in red blood. At first Leo thinks he’s been shot, then he sees the blood on the cop’s chin and remembers the coughing fits. The cop tries to use the side of the house to prop himself up and stand up but slides down again. Leo realizes he’s sicker than he thought. Then Leo hears a tapping noise. His eyes dart around then land on a small window a few feet above and to the left of the cop. He sees a small hand pulling a black sheet back from the window, then he sees the top of a head and an eye. There’s a fear in the eye as the person quickly pushes the black sheet back to cover the window. It’s then that he notices the cop is looking directly at him. The cop holds Leo’s gaze for two long seconds then stands up and hobbles around the front of the house and enters the front door. 

Leo stands frozen before he makes a decision. He runs back the way he came toward the opening of the lot and, hugging the last steel fence post, swings onto the small lawn of the house and runs toward the side. He hears something faint inside of the house—two men yelling maybe. Then it’s quiet. Now crouching against the front of the house, Leo takes a step toward the front door. He notes that it’s a few inches open. 

Once inside the house, Leo pads across a small entryway of linoleum before he steps onto the too-thick carpet. It’s dark inside. He turns left and sees a cheap wooden door with a padlock on it. He quickly connects that door with the blacked out window and the fearful eye. Leo’s attention is pulled down the hall to the right when he senses a body cross into a room on the far side of the hall which he knows is the kitchen, the way you always know where the kitchen in a house is. He tucks himself up against a small alcove. He forces himself to check his breathing then peaks around the wall. All clear now, he steps out into the hallway and takes a few cautious steps down the hall. The gun is in his hand. 

When Leo gets to the dark kitchen, he trips over something and smashes into the countertop, knocking pans off the stovetop and making way too much noise. He rights himself. One of the pans is still warm to the touch. He freezes and listens—he made too much noise for nothing to happen. 

Then he looks down and realized he hadn’t tripped over a duffel bag. It’s the cop laid out face down, limp and heavy like a sack of rice near the entrance to the kitchen. On the far side of the kitchen by a door that indeed goes outside into the side yard, he sees Cam’s body, his chest bullet-ridden. He’s dead. 

It’s then that the man walks out from the shadows of the opposite corner of the kitchen, just in front of what looks to be a pantry door. It takes Leo a moment to see the shotgun pointed at him. 

The man walks toward Leo speaking in a language that sounds like Russian. Leo doesn’t need an interpreter to know that the man is spewing hateful violence. Leo holds his own gun up and points it at the man. 

Then suddenly, his hands feel thick around the joints and his arms feel heavy. Leo looks at his arm and is surprised to see he’s barely holding the gun above his hip, its barrel facing a spot on the floor well away from Russian. Then Leo falls back against the counter and slides down to the floor. He drops the gun and clutches his chest, gasping for breath. What is happening? Has he been stabbed or shot? Did it happen so fast that he didn’t hear the gun discharge?

But he searches his chest with his hands and doesn’t feel any injuries or blood. 

The man with the shotgun is surprised then smiles and scoops up the gun. He grunts something in Russian and holds the gun on Leo. Leo’s eyes start to cloud up. He sees two hazy outlines of the man as he approaches him. He holds his hands up in a weak form of defense. The man slaps his arms down and Leo can’t lift them back up even though he wants to. His heart beats in his head louder now. From the corner of his eye, he sees one of the pans he knocked off the counter earlier. Half a dozen shrimp tails dot the floor around it. Fuck. 

He hadn’t carried an epipen with him for six years. It has always been in the bottom of Celia’s purse. He thinks back on that first date then his eyes darken as the following six years with her play back in his head in three seconds. 


Copyright Chris McCarthy and MDA Press, 2024, Graphics by Chris McCarthy with Imagen3.

Exponential Threat, Part 1

by Chris McCarthy

Exponential Threat
Exponential Threat (image created with Imagen3 by Chris McCarthy )

Amanda runs onto the bridge and b-lines for the controls. Chase Markley sits low in the captain’s chair with his feet on the console, looking lazily out the glass viewport. 

“What did you do?!” Amanda asks as her eyes dance apprehensively over the data displayed on the translucent master control interface that appears as a large square in a section of the clear glass, which, with a flick of the finger can also be pulled off and turned into a twin holoscreen that a crew member can look at wherever they’re comfortable. 

Chase looks over at Amanda, his head resting in his clasped hands above his shoulders. “Huh? Oh I’d heard about the light curtains of Tumis and really wanted to see them. So I decided to move things along. Turns out they’re not that cool.”

Amanda looks out the viewport at the pink and green auroras then back at Chase, incredulous. “So you defied my orders and entered Tumis’ territorial boundary? You know how delicate this mission is, right? You understand our position in the Intergalactic Legion relies on our ability to complete this mission for Admiral Flake with no complications?” 

“Yeah, I do.” Chase kicks his muscular legs down and groans as he stands up and straightens out his back. “We’re here to find Baldrick and bring him back to Legion HQ. Easy peasy.”

“So relaxed. You narrowly avoided a death sentence for illegal smuggling four days ago!” Amanda says. 

“And got out of that trial being named your co-captain.” Chase counters. 

“Yeah, I don’t think that’s actually a true union designation. I’m gonna have Salamander look into it. But for now, I need to, you know, worry about saving us from mandatory ten year prison stints on the most fascist planet in history, because we’re carrying illegal cargo.” 

Salamander runs onto the bridge and looks over Amanda’s shoulder at the interface screen. He looks out into space then takes another look at the screen. “Um, Amanda…”

Amanda waves him off, “Not now Salamander. Adults are speaking. Or at least one is.” 

“That’s no way to talk to your father. Have some respect.” Chase says, turning around in his chair to face the inside of the bridge.

“We need to come up with a plan for when we definitely get boarded by customs for smuggling a blacklisted species…” Amanda says, breathing in and out in a controlled way, attempting to remain calm. 

“Oh. Is this about the magno-puppy?” Chase asks. 

“You knew about it?!” Amanda asks through gritted teeth. 

“Yeah, I didn’t think there was any harm in letting Lisa make extra money so she could finally quit this dead-end job and buy a pod home on Zantaria.” 

“What!? This is why you’re not fit to be a co-captain. I can’t believe you didn’t think this would be a problem. First thing I’m going to do when—if—we get out of this, is to get you decommissioned for insubordination.”

“I’m a captain, so who am I subordinate to?”

“You didn’t share crucial information about our crew with the other captain—me.” Amanda says. 

“It’s not my fault the crew isn’t comfortable talking to you about personal matters.” Chase says. 

“That’s not our job, Chase.” 

Chase turns to Amanda, sensing her deeper anger, “Let’s not be irrational.”

“The only thing irrational on this bridge is you thinking that t-shirt is flattering.” Amanda says, putting her face in her hands then brushing her hair back, composing herself. 

Chase pretends to brush off the comment, but looks quickly at his shirt and the thickness just above his waistline. He sucks in his stomach.

“Amanda!” Salamander yells. 

“What, Sal? Spit it out!” Amanda yells back.

“We have company.” Salamander gestures at the display then with his thumb and index finger expands the space it takes up on the glass viewport to twice the size. 

Amanda and Chase both look at the screen. It’s a clear image of an approaching vessel. 

“Oh, shit. We’re getting boarded.” Amanda sits down in the captain’s chair. 

Winston and Lisa run onto the bridge just as another alert TRILLS briefly followed by a computer generated woman’s voice this time. Red lights flash on the deck. Ship approaching. Preparing life support systems for additional boarding of five persons.

Amanda looks through the glass then at Salamander. “Five persons? Wait, is that…?” 

Salamander puts his hand to his chin. “Oh, this isn’t good.” 

Lisa squints her eyes. That looks like an ambassador’s seal.” 

“Why would such a high level ship be interested in us?” Amanda asks the bridge in general. “They could have just sent a customs droid ship. I don’t…”

She’s cut off by the soothing female computer voice saying, “More data collected. The ship is the official vessel of his excellency Ambassador Edwin Trong. Prepare for an official boarding.”

They all look out the glass viewport. Coming into view is a small green ship with yellow lines on each side. 

Lisa leans agains the glass viewport. “An official boarding? Ugh. Those are the worst.”

Amanda turns from the viewport. “Does anyone even remember how to do those? Winston, look up the protocol. It hasn’t changed in a hundred years so even you should be able to handle the task.” 

“On it,” says Winston, “thanks for having faith in me.” Winston sits down at his console, then winces as he catches the sarcasm in Amanda’s comment. He puts one hand to his temple, leans back and closes his eyes, then thinks better of it. He looks over at the neural dock headpiece attached to his console to his left. He wipes off some dust and attaches it to the left side of his head, blue and red lights indicating the system has engaged.

“Wait a minute…Edwin Trong?” Amanda looks to the handplant device on her wrist. Photos of a nerdy thirteen year old boy pop up. She slides to one of the same boy, just a bit older. She slides through a few more images. “Shit, I went to school with Edwin Trong.”

“Then, maybe he’ll let us off without the mandatory ten-year prison sentence for smuggling,” Salamander says. This is a good thing.”

“No, Salamander,” says Amanda, “This is not a good thing. We were supposed to go to the Neon Gala together in year eleven, but…”

Chase looks over, “You went with that pretty girl with the bangs. What was her name?”

“Her name was… Edwina. Edwin’s sister.” 

“Oh, that’s right! I forgot about the carnage that cost him and his family—Amanda, you’re a true Markley.” Chase says, as the realization of what this scarring betrayal could mean. “Oh shit.” 

“Yeah, oh shit.” Amanda says wryly.

“Oh fuck us,” Salamander says, leaning down on his knees catching his breath. 

Winston stands up suddenly, a marked change in his confidence. “Ok, I downloaded the protocols. Amanda, you need to stand right at the center of the Intergalactic Legion Seal. Let’s go.” 

Lisa looks surprised, noticing the neural dock in Winston’s hand. “Wait, did you just do a system update?” 

Winston’s eyes cut into her, a new power behind his eyes, which now blaze a bright green. “Yeah. I’m fully updated. I figured, what’s the point of me halting my growth? What am I waiting for? Plus, now I know kung fu.”

Chase looks over, “Great line!”

Lisa’s eyes rest on Winston for another moment before she lets out an anxious breath out and looks out the viewport at the approaching ship.

“That’s a joke.” Winston smiles, then says to himself: “I have a sense of humor now!” Winston shuffles on the balls of his feet, his hands up in mock fighting position.

Salamander walks to the backside of the bridge. “I think I remember my official posture. It’s been a while but I think I stand about here. Standing frozen like a status is sort of in the DNA.”

Amanda hesitates but Winston grabs her gently by the shoulder and steers her toward the seal at the center of the bridge. “Over here, Amanda.” She follows him, surprised at his new confidence. 

Amanda follows his lead. “OK, everyone, do exactly as Winston says. If we perform our ceremonial receiving ritual perfectly, we might be able to buy enough time to…” 

“To what?” Chase asks. 

“I don’t know, I don’t know — we’ll be able to buy ourselves some more time. That’s all I have for now. I need time to think.” Amanda says. 

Winston claps his hands, “OK, everyone else, follow Salamander’s lead and line up behind Amanda. Lisa, come on. You too, hotshot.” He says talking to Chase. 

Chase lifts his eyebrows. 

“We have three minutes, guys. Let’s go!” Winston says, suddenly all business

——Three minutes later

Ambassador Trong walks onto the bridge wearing official satin robes of green and yellow. His attaches, Liam and Sturgis, enter behind him in a heightened dramatic way, stone faced, their eyes not connecting with anyone. A woman named Maritha, his pageant guard, walks just in front of the ambassador waving a green and yellow flag wherever he is about to walk to give him the pageantry he deserves.

Finally, after taking in the bridge for a few brief moments, Trong deigns to look in the direction of Amanda and her crew, who stand in the center of the bridge, all adopting the official postures of their rank and place. 

Captain Amanda Markley. It’s been a long time since the Perihelion Academy.” Trong says. 

Amanda stands stone-faced and empty-eyed, like the rest of her crew. Save for Chase, who is no longer on the bridge. 

——

End Part 1

Copyright Chris McCarthy 2024, Graphics by Chris McCarthy with Imagen3.

Swimming Robot

Jiaji Li has completed the design, fabrication and testing of his Oar-Driven Unmanned Surface Vehicle, better known as his Swimming Robot.

The video below shows a rendering of the final design, testing of the coordination of the oars, which are driven in sets of three by two motors. And, finally, shows the robot swimming in a straight line movement, gentle turning, and movement to two separate locations.

This water surface robot is a remarkable demonstration of the capabilities of 3D printed spherical linkages.

Red Lines, Part 1

By Chris McCarthy


The cop in the front seat was coughing. A guttural sickly cough, the kind that gives you pause. Leo had no idea what was going on. He looked through the windows, he wasn’t even belted in the back of the car, much less cuffed. He wasn’t a prisoner. His mind was finally ready to start processing how he got there, where they were going and what was going to happen when they got there. In his gut he sort of already knew. 

Another rough coughing fit, then the cop leaned over and searched with his free hand under the passenger seat. He pulled out a small square microfiber gun cloth and, still looking out the windshield with his deeply bloodshot eyes, handed it over the seat back to Leo. 

Leo looked up, confused, and locked eyes with the cop in the rearview mirror. 

“For the blood,” the cop said before looking away to make a quick lane change to get onto the 405 freeway heading south.

Leo looked down at his hands and saw the fresh red blood on the knuckles of his left hand. Most of it wasn’t his. The pain set in as the shock wore off. 

——Ninety Minutes Earlier

The two women were deeply concerned. Well, the one was. Her son, Adam, is sixteen years old, and has a lot of friends at the nearby high school. He’s not necessarily a heartthrob, but he does ok. OK enough that he has things to do other than attend class. Things that, yes, sometimes involve girls. The mother of the boy wanted this in the conversation, as if she pulled it out as an imaginary item and sat it on the table for the two of them of them to consider. The one woman who wasn’t as deeply concerned said she thought if Adam could get in this summer at one of the chemistry labs nearby for an internship, he might be able to hold that internship the following year and it will look good as a long term “extracurricular” on his college applications. The concern of the mother was palpable and she was clearly paying the slightly less concerned woman for this advice. 

It wasn’t the first time Leo had heard this conversation. This was Manhattan Beach, one of the richest enclaves in Los Angeles. The mother was telegraphing Torrance or Redondo Beach, which meant that she would fight even more for the things the people in her community deemed were the steps to a good life. The people just outside of the circle were the ones with the sharpest claws. Leo could relate. He’d always just been right outside of everything, an observer, close enough to the warmth to have the capacity to miss it. He’d overheard similar conversations recently. These education consultants who billed $200 a session and could supposedly plan your teenager’s (sometimes the planning started sooner) path to college—a UC and possibly a minor Ivy League school or respected school like University of Michigan. Fuck, even Long Beach State was starting to get hard to get into. 

As Leo sat in the expensive coffee shop just off a busy street in Los Angeles, frustrated with his script he looked out into the parking lot, staring at the late model silver Honda Civic, a car about as exciting as the backside of a thumb. And admittedly, like a thumb: useful, practical and allowing for all kinds of possibilities, but really fucking boring. He knew he was being particularly harsh to the make and model of car because its owner was fucking the girl he loved. Or used to love. Or… It was confusing. The uncomfortable thought that he didn’t really understand his true feelings and probably needed to spend more time untangling them and examining them in greater detail bubbled up, but he pushed it away just as quickly. 

Asher, the guy fucking Leo’s girlfriend—ok, ex-girlfriend, Leo would allow—worked at a soulless Citibank branch on the westernmost side of the shopping center, just off the perpetually busy westside LA artery Sepulveda Boulevard, which just a few miles down the road in either direction was known by its more famous name, Pacific Coast Highway. Leo’s table faced the front of the coffee shop with its ceiling to floor windows, giving him an unobstructed view of the bank’s employee parking lot. 

Leo had been coming to the coffee shop every morning for a week. The day Celia left him, which was sixteen days after they had signed a lease on a two bedroom apartment in Torrance, and twelve days after delivery of a new dresser and new bed, still in the boxes, Leo found a wet and bent business card in the bathroom trashcan underneath the bag, grimy and stuck to the side. Leo noted that a cell phone number was written in blue ink on the card—this was something beyond a business card hand-off. He flashed to a vision of Celia in the bathroom, the door locked, smiling breathlessly as she sent an illicit text message to the person possessing the name on the business card: Asher Williams, Citibank Location 103 Branch Manager. 

Celia had told Leo she was staying at her friend’s apartment in Pasadena, a white lie so easily debunked that her lack of effort in covering her tracks hurt him to his bones. 

He felt another similar pain, this one was in his chest for some reason, as he sat in the coffee shop looking out the window, the still powerful heat of the sun on the mid-November day warming his face. Not that he felt it.  He felt… nothing, maybe. That felt dramatic to think. But it also felt accurate, he thought as he watched a crow inspect a discarded Fat Burger wrapper in the parking lot before flying away…

When out of nowhere Celia walked up to the car… Leo wasn’t sure if his mouth dropped open. The look on her face. The way she walked, head up high, already wearing a half-smile in excitement. It was a punch in the gut. Seeing her so… happy. 

A moment later, Asher walked out the front of the bank towards the car. They embraced and kissed then walked over to Chipotle. A cheeky little lunch date—a bank manager and a paralegal. How fucking cute. Maybe the kid will go to Long Beach State.

It’s the ease of the hug, the kiss, the holding hands, the opening of the door for her that hit him like a splash of ice cold water to the face. The familiarity. Leo considered himself a student of human nature, often finding himself at a library in the middle of the day reading some new book on anthropology or social sciences, so…

How long has this been going on? He asked himself or rather tortured himself with the question. 

Much longer than she admitted. Why she had destroyed him, lied to him, he had no idea. Couldn’t pinpoint one thing. Sure, they had had problems. His career hadn’t taken off the way he thought it would with his talent. And, sure, he had been fired almost exactly a year ago, but the guy who fired him was an asshole with an axe to grind who didn’t understand what marketing really is, the nuance of it, the time it takes… No, none of it was Leo’s fault. He could hang his hat on that. Besides, Leo was an artist. This was an extended rough patch. A rough patch with no sex for the last six months. How long had she been with this guy? Suddenly, moments where Celia avoided Leo’s touch flashed in his memory and he desperately tried to reach out to dates on an invisible calendar in his mind.  

Leo was reminded of the paranoia of the Bill Withers song Who is He (and what is he to you?) where the listener is in the POV of a man walking with his girlfriend as they pass someone who is more than just a passerby to the woman. 

Leo waited for thirty eight minutes, and they finally came out of the restaurant. In a quick fluid movement, Celia got up on her tiptoes and kissed Asher. Leo watched her familiar walk then lost her as she passed around the side of building to the west side of the parking lot, presumably to her car. 

Leo looked at his untouched six dollar iced Americano with oat milk sweating in the sun and felt a heat in his face. He was frozen in place. A melting piece of ice shifted in the drink. Leo stood up and grabbed his backpack, a prop he hadn’t opened once today, and walked out the door. But it was too late to get to Celia, besides suddenly he felt smaller than he was sad, and what would he do anyway, so he hid his face and walked back toward the coffee shop. It was then he realized Asher has walked behind him toward the opposite side of the building away from Celia. The smaller less traveled east side of the parking lot where a hardly used side door of the coffee shop opens to another back door to the high class gym next door that some patrons run out of during the presumed cardio section of some workout. But most of the time, no one used this side of the parking lot, so it was empty. 

“Yeah babe, I had a meeting during lunch,” Asher said into the phone. Leo heard this clearly. “We still on for tonight?” Asher turned the corner and Leo made a quick decision. He didn’t know what it meant but he was excited—it was a good feeling to be distracted by right then. He darted back into the coffee shop instead of following Asher around the side of the building and being obvious about it. He walked to the bathroom at the back of the shop, his eyes already on the side door that exits to the side parking lot. 

Leo popped out of the side door and descended the three concrete steps, pretending to look into his phone. Asher was puffing on a lit cigarette leaning against the gym as he spoke into his phone, his back to Leo. Who smokes in 2024? This fucking guy who is clearly seeing another woman—she chose this guy over me? Leo tucked his phone back into his pocket and looked up again and saw Asher’s head back around the building to the front parking lot, his cigarette still smoking on the asphalt. Leo takes a step forward then stops himself, suspended directionless but now seething, his pulse beating in his ears.

Then SMAAASH! 


Red Lines Cover
Red Lines Cover by Sara McCarthy

Leo looked over to the back of the building. He heard the sound of crunching plastic as a green beat-up late 90’s Eclipse slammed into the three foot tall steel yellow barrier that bends around the building toward the back of the coffee shop. The building that today held the coffee shop, a nail salon, and a tailor shop, at one point was a Circuit City where trucks would snake around the back and drop off large items, hence the industrial grade protective steel barriers, which probably only survived to this day because they weren’t noticeable from the current day business side of the building and would be expensive to remove. 

Leo watched, stunned, as the car rolled back from the yellow steel barrier it had just hit, a low speed collision that made no sense, yellow paint now caked on its front bumper. Independent of the crash, the car was in terrible condition. The hood was painted a different shade of green than the rest of the car, rust seeped through all over so much so that the tail gate looked like it would disintegrate with the flick of a finger.  

He watched as the driver leaned his head down a bit, gathered himself after perhaps knocking his head on the steering wheel or on the drivers side door window. Leo looked around but no one else was around to share in the strangeness of the moment. The driver looked to be in his fifties with a weathered and worn face. He wore a cruel expression that Leo understood to be his default look. It was a face that sets off alarm bells in your gut and instinctively makes you turn away. 

Then the passenger door swung open and the woman jumped out of the car. She wore purple Uggs, off-brand high rise athletic shorts, and a dirty yellow men’s hoodie that slid down off one shoulder. None of it fit well. Leo caught the first look of her face as she ran toward the back of the car, tripped on her boot and fell backward, landing behind the bumper of the car. She had streaked eye-liner on her face, behind which Leo could see clear acne scars. She possessed wide, intelligent eyes that looked like they had once been kind and open to the world but were now fixed into tight small daggers for self preservation. Hers was a face that radiated neglect. 

The man, in full control, opened his door and exited toward the back of the car. He threw his hands up into the air violently. 

“Get in the fucking car, bitch.”

On the ground, she slid herself away from him with her feet as she simultaneously tried to pick herself up. 

“No. No. Let me go, you psycho!” 

The woman quickly got to her feet and ran away toward a small section of dirt behind the side parking lot and the small street behind it. That’s when he looked right at Leo. 

“What are you looking at, buddy?”

Something about the word buddy stopped Leo from listening to the alarm bells and running in the opposite direction. And he couldn’t shake the look of fear on the woman’s face. So, instead, he surprised himself and took a step closer. 

Leo noticed his shaking voice start to get more steady. “What are you doing with this woman?”

The man considered Leo for another moment then turned to run after the woman. He caught up to her with ease and grabbed her by the arm, viciously turning her toward him. He walked her toward the car as she tried to use her body weight to pull herself way from him. 

She screamed, “Get the fuck off of me.”  

Leo looked around for help then said, “Let her go. What is this? What are you doing?”

“Stay the fuck back,” the man yelled. But Leo hadn’t move forward. 

But now he felt himself move forward. And with this one step, there was a clarity.

As the man shoved the woman into the passenger side of the car and elbowed her in the face for good measure, Leo found himself walking around the backside of the car. 

The man trained his eyes on Leo and slowly turned toward him, his open mouth and sharply-turned neck telegraphing his surprise.

“You don’t want to get involved bro. I’ll fuck you up.” 

“Let me out,” the woman yelled.

The man slammed the car door and pointed at her. 

“Stay the fuck inside the car,” he said.

Then all was silent. She gave up. The whole episode could have been over. Swept under the rug, no repercussions. The man turned toward Leo. 

As he took a step towards Leo, his face became more clear. He wasn’t in his fifties. He looked to be more like early forties but with a pock-marked overly tanned face, and a scar running deep over his right eyebrow down just past the top of his cheekbone. A faded neck tattoo peaked up above his shirt line. 

Leo’s eyes darted to the woman in the car. Through the tinted window he could see she had her head in her hands, crying and defeated. 

The man got another step closer. Leo knew he should run. And that’s when he felt the brick in his hand. 

——

Sitting in the back of the police car, Leo saw PCH differently than he’d ever seen it before. The spaces between buildings, the dumpster-filled alleys all came into stark focus. The small little lawless sections of this upscale area and every area.

“Is that guy…?” Leo asked.

“What do you think, man?” The cop asked, almost chuckling. 

The cop then leaned over and said something quietly into the radio in his right hand, an action that caught Leo’s rapt attention.

“What are you…”

“It’s not about you.” The cop’s whole body shuddered as he again coughed into his hand, which still awkwardly clutched the radio receiver. 

Leo asked, “Where are we going?” 

“We’re taking a short trip.”

Leo looked down at his hands. 

“Can you just drop me off here?”

The cop laughed hard until he coughed again. This time Leo noticed there was blood. 

“OK, so where are we going?”

“To get the rest of them.”

“The rest of them?” 

“Let’s listen to some music. You like rap?” 

The cops turned the radio up. Big X The Plug’s clogged-throat and lispy boasts in the song MmmHmm filled the car as Leo takes a deep breath and leans back in his seat.

——


Next Episode:  Leo and the cop drive to Santa Ana to find the safe house where they have intel that other victims are imprisoned. They learn that a ship has left from San Pedro that evening, but at the house, find evidence linking this Russian gang with the kidnapping of the cop’s daughter. The house is under close surveillance, so Leo and the cop’s journey back up the freeway isn’t a solo one.

Copyright Chris McCarthy and MDA Press 2024, Graphic by Sara McCarthy Designs

Eight Legs, Two Motors and a Lot of Personality

Please take a look at the videos demonstrating these Robot Walkers. Our study of minimal actuation for walking robots has lead to pairs of specialized leg mechanisms at each of four corners of the walker, eight in all. The robot is steerable with two separate drive motors, that is each side has four leg mechanisms connected through a gear train to a motor. This is a lot of moving parts, but the result is remarkable.

All of these robot walkers respond to commands from an infra-red remote control. They can go forward and backwards, speed up and slow down, turn right and left, and even spin in place. 

It was a pleasure working with students on these projects. Their creativity and enthusiasm is fun to be around.

Stegosaurus Walker: This first video shows the Stegosaurus Walker designed and built by the team of Cristian Albrektsen, Itzel Montoya, Matthew Reber, John Williams, and Megan Yang. Select this link or the image.

The Grinch Walker: This second walker captures the Grinch Who Stole Christmas at the moment he brings the toys back to Whoville. It was designed and built by Melissa Lepe, Esteban Ruiz, Sebastian Petcu, Purushotham Verma and Jasper Yao. Select this link or the image.

Tio de Nadal Walker: The third walker celebrates a Catalan tradition known as the Tio de Nadal, which is a magical log that delivers presents and warms the family. It was designed and built by Paula Simo, Lois Meira, Eudald Sangenis, and Marc Quiroga. Select this link or the image.

Jiaji Li’s Robotic Rowboat

Jiaji Li has succeeded in building a prototype Robotic Rowboat. I have used 3D printing technology ever since it was introduced decades ago to build spatial mechanisms and routinely failed, which is why this is a particularly satisfying outcome.

He convinced me to buy an inexpensive 3D printer and said he was sure PLA (poly lactic acid) would provide a strong but light-weight product. So I gave it a chance and find the result to be very nice.

Please take a look: Robotic Rowboat