Robots

These are my “Go To” robot brains or robot “compute”. Below you’ll see an Arduino Leonardo ~$25, an ESP 8266 (NodeMCU) ~$8, and a Raspberry Pi 3 ~$45. I’ve included links to purchase below along with their specs as well as the specs of other similar items.

So why these items? Well the Leonardo has a friendlier USB connector, a Micro USB, and more digital, PWM and Analog inputs compared to the Uno. The ESP 8266 isn’t as powerful as the ESP 32, but the compile time is faster and I mostly work with WiFi vs. Bluetooth. The Raspberry Pi 3, also isn’t as powerful as the Pi 4 or Pi 5, but it also takes the Micro USB cable and the camera connector is more compatible with older less “Pure” cameras. Also because I do most of my work via API / Wi-Fi, it’s perfect for being a connector to all things on the Robot to the network.

Here’s a summary of all the stuff I’ve purchased over the years with some specs.

Device	Connector	Input Power Voltage	Memory	Speed	MIPS	Inputs	Notes
Arduino Uno	USB-B	7-12V DC (via barrel jack) / 5V USB	32K Flash, 2K SRAM	16 MHz	16 MIPS	14 Digital I/O (6 PWM), 6 Analog inputs, 1 Serial (UART)	Arduino Compiled
Arduino Leonardo	MicroUSB	7-12V DC (via barrel jack) / 5V USB	32K Flash, 2.5K SRAM	16 MHz	16 MIPS	20 Digital I/O (7 PWM), 12 Analog inputs, 1 Serial (UART), 1 USB	Arduino Compiled
Arduino Mega256	USB-B	7-12V DC (via barrel jack) / 5V USB	256K Flash, 8K SRAM	16 MHz	16 MIPS	54 Digital I/O (15 PWM), 16 Analog inputs, 4 Serial (UART)	Arduino Compiled
ESP8266	MicroUSB	3.0V – 3.6V	4MB Flash, 80K SRAM	80-160 MHz	80-160 MIPS	17 GPIO (up to 9 usable), 1 WiFi, 1 Serial (UART)	Arduino Compiled, WiFi
ESP32	MicroUSB	3.0V – 3.6V	4MB Flash, 520K SRAM	240 MHz	600 MIPS	36 GPIO, 16 PWM, 2 WiFi, 2 Bluetooth, 3 Serial (UART)	Arduino Compiled, Bluetooth, Wi-Fi, Dual Core
ESP32-CAM	MicroUSB	3.0V – 3.6V	4MB Flash, 520K SRAM	240 MHz	600 MIPS	11 GPIO, 1 Camera, 1 WiFi, 2 Bluetooth, 3 Serial (UART)	Arduino Compiled, Bluetooth, Wi-Fi, Dual Core w/ Camera
Raspberry Pi Zero	MicroUSB	5V	512 MB RAM	1 GHz	2000 MIPS	40 GPIO, 1 Camera Serial Interface (CSI), 1 Serial (UART), 1 I2C, 1 SPI	Full OS
Raspberry Pi Zero W	MicroUSB	5V	512 MB RAM	1 GHz	2000 MIPS	40 GPIO, 1 Camera Serial Interface (CSI), 1 WiFi, 1 Bluetooth, 1 Serial (UART), 1 I2C, 1 SPI	Full OS, Wireless
Raspberry Pi Zero 2	MicroUSB	5V	512 MB RAM	1 GHz	4000 MIPS	40 GPIO, 1 Camera Serial Interface (CSI), 1 WiFi, 1 Bluetooth, 1 Serial (UART), 1 I2C, 1 SPI	Full OS, Wireless, Quad Core
Raspberry Pi	MicroUSB	5V	256-512 MB RAM	700 MHz	1000 MIPS	26 GPIO, 1 Camera Serial Interface (CSI), 1 Serial (UART), 1 I2C, 1 SPI	Full OS
Raspberry Pi B	MicroUSB	5V	512 MB RAM	700 MHz	1000 MIPS	26 GPIO, 1 Camera Serial Interface (CSI), 1 Serial (UART), 1 I2C, 1 SPI	Full OS
Raspberry Pi 2	MicroUSB	5V	1 GB RAM	900 MHz	3600 MIPS	40 GPIO, 1 Camera Serial Interface (CSI), 1 Serial (UART), 1 I2C, 1 SPI	Full OS, Quad Core
Raspberry Pi 3	MicroUSB	5V	1 GB RAM	1.2 GHz	4800 MIPS	40 GPIO, 1 Camera Serial Interface (CSI), 1 WiFi, 1 Bluetooth, 1 Serial (UART), 1 I2C, 1 SPI	Full OS, Bluetooth, WiFi, Quad Core
Raspberry Pi 4	USB-C	5V	1, 2, 4, 8 GB RAM	1.5 GHz	6000 MIPS	40 GPIO, 1 Camera Serial Interface (CSI), 1 WiFi, 1 Bluetooth, 1 Serial (UART), 2 I2C, 1 SPI	Full OS, Bluetooth, WiFi, Quad Core
Raspberry Pi 5	USB-C	5V	1, 2, 4, 8 GB RAM	2.4 GHz	9600 MIPS	40 GPIO, 2 Camera Serial Interfaces (CSI), 1 WiFi, 1 Bluetooth, 1 Serial (UART), 2 I2C, 1 SPI	Full OS, Bluetooth, WiFi, Quad Core

Here’s a few robots and videos from 2007 to 2009.

CRAB Robot Diagnostic

This is a small robot I hooked up to my PC and I added some TTS (Text-To-Speech). I think this is around 2007, so it’s pretty old footage. For anyone that recognizes it, this is the same J.A.R.V.I.S. voice I use for my house and during my CodeMash talks.

Same robot but doing some computer vision. I ended up using blue because of the low light and the cheap webcam tended to make everything green & red.

Feynman Series – Navigating The Sidewalk

Little bit more coding than I thought to make this work. This is a smaller version of the Feynman Series robot, the Feynman Jr. series. I ended up using some different motors as well, two NPC-2212 with 6″ wheels. Turns out it was a very rough ride, eventually the webcam servo mount broke because of the shock.

This is a continued post about my robots as I prepare to archive and rebuild ScottsBots.Com.

Feynman MK1 – 2002

The “Feynman” name for my robots actually comes from the names of the computers in my house, this computer housed in wood below was called Feynman, and I happened to turn it into a robot.

This robot came equipped with a robot arm, sonar, a compass, and a webcam. The chassis was made from plywood and PVC. The motors were Black & Decker cordless drills. I powered the drills via speed controls from robot control cars. It had speakers and could “talk” using primitive text to speech. It was still powered via 110 VAC.

The computer itself was an AMD K6-2 500MHz, running Windows 2000 and Visual Basic 6. I programmed and tested it using VNC. I used a Basic Stamp 2 to get sensor readings from the sonar, compass and infrared sensors. I used the Scott Edwards Mini-SSC to control PWM channels on the speed controller connected to the drill motors.

Computer Vision Tinkering

From the image above, I also started to tinker with computer vision. This was a simple VB6 thresholding program, where i looped through all the pixels and if they were below a certain number I changed them to zero (black) and if they were above it, I changed the pixel to 255 (white).

Feynman MK3 – 2003

This version contained a lot of upgrades. I still had a plywood base but I used 80/20 Aluminum Extrusion for the chassis and I used 2 33AH Batteries for power. I upgraded the drive motors to use two windshield wiper motors from an F-150. I upgraded the speed controls to two Victor 883 from IFI Robotics @$150 each. I upgraded the webcams to Two Pyro 1394 Firewire webcams.

The computer changed to a lower powered version. VIA EPIA M10000 Mini-ITX with 259 MB of ram and a 20GB HDD. It had Wi-Fi and all the software to program and run it was 100% Java.

This is a picture of the base of the robot. The drive system used coupling nuts connected directly to the shaft of the wiper motors and the wheels. This wasn’t very efficient and the motors themselves didn’t prove to be that reliable. Another thing I didn’t do well with this design was account for the spacing of the caster wheels. They were a little above the drive wheel and movement of this robot was a little jarring as it would rock back and forth when starting and stopping. This rocking eventually led a really difficult time doing computer vision with the two cameras, ultimately i needed a better solution.

Feynman MK5 – 2004

This was the robot I used for my book, The Definitive Guide to Building Java Robots.

This design and software to run it is outlined completely in the book. Additional upgrades include PVC from McMaster Carr. Two new NPC-41250 Motors from National Power Chair. 3 SRF-4 Devantech Sonar Sensors. I also removed the front caster made it a little backwards heavy so it rested on the batteries. This created a much more stable platform for moving around doing navigation.

Feynman MK6 – 2005

Once I wrote the book I started getting invited to speak at local user groups and conferences about Java and Robots.

I created a switch so that I could remote control the robot as I would drive it places. This is the robot at some location in town, it could even be a conference. This robot is mostly the same as Feynman 5, just a little taller with a single webcam.

I think this was the first version of my robot I took to CodeMash. as speaker.

Feynman MK7 – 2006

This is the final version of the robot.

Most of this robot remains unchanged to this day. I removed and upgraded the computer a few times, eventually switching to a Raspberry Pi, but ultimately the robot proved too difficult to transport. It weighted about 200 pounds and required 2-3 people to load into the truck to transport to conferences and meet-ups. Currently this robot sits in the garage unused. 🙁

I thought I’d put a post together summarizing some of my robots as I prepare to archive and rebuild ScottsBots.Com.

TetherBot – 1999

I built this robot in 1999. I hacked two hobby servers (Futaba 3003) to make it move and built my own sensors with some parts from Radio Shack. To move this robot I connected an ethernet cable to the parallel port on my Windows 98 Machine.

Baby Joe – 2001

This was my second and third robot. I reused the hacked servo motors from TetherBot, but this time I used a Basic Stamp microcontroller to control the IR sensors and send PWM signals to the servo motors. I also used Aluminum and plexiglass as construction materials.

Rovey – 2002

I started to experiment with different chassis materials (this time PVC). Also because I had more servos (pan/tilt) webcam and 2 drive servos (same ones) I upgraded the controller from a Basic Stamp 2 to a Scott Edwards Mini-SSC. This device allowed me to send commands to the servos with 3 bytes (255, servo(0-7), position (0-255). So (255,0,127) would send a stop/neutral pulse to servo connected to the 0 pin. (255,0,0) would send full clockwise pulse to the servo on pin 0. (255,0,255) would send a full counter clockwise pulse to the servo on pin 0. This is a great little board and one I use to this day on some of my new robots.

I created this robot for a talk at COSI. The idea was that students could login and control the robot from a web browser. The idea of the talk was to connect with Mars Pathfinder robot which at the time was discovering it’s way around Mars. The photo isn’t great I tried to create a Martian landscape and added rocks for the robot to explore. The robot was tethered so it could have continuous power, but to prevent the robot from getting tangled I connected the robot wires to a string hung from the ceiling.

The temperature bot a.k.a. the algorithm that controls the temperature in my house underwent a slight upgrade this week.

The old algorithm:

If (setTemperature > averageHouseTemperature) HEAT, otherwise COOL.

Simple right? Not so much.

Scenario 1:

Let’s say I set the temperature to 70, and it’s currently 71 in the house. According to the bot, the AC would go on, this would be fine if it was 80 degrees outside but not if it’s 55. I’d rather just open the windows, and furthermore, I want it to just stay off until I close the windows.

Scenario 2:

Let’s say I set the temperature to 72, and it’s currently 70 in the house. According to the Bot, the HEAT would go on, this would be fine if it was 55 degrees outside, but not if it’s 80. I’d rather just let it heat up naturally, then if it gets above 72, I want it the AC to come on.

Let’s look at these scenarios in more detail.

In Scenario 1, the set temp is LOWER than the average house temperature, rather than the AC turning on, I want to open the windows and I want the HEAT/AC to stay OFF.

In Scenario 2, the set temp is HIGHER than the average house temperature, rather than the HEAT turning on, I want the house to just heat up naturally but I want AC to kick on if it gets too HOT.

The new LOGIC.

return (outdoorTemp < 62 || outdoorTemp < 67 && setTemp > indoorTemp) 
   ? 'heat' : 'cool';

The final piece of the puzzle is I need to call this on an interval since the indoor and outdoor temperature will fluctuate throughout the day.

(Updated 4/18/2018)