Balancing Robot Vehicle 
Sunday, December 10, 2017, 02:34 AM - Robots
Posted by Administrator

Balancing Robot Vehicle

I used this guy's YABR (Yet Another Balancing Robot) project as my guide:

I used his code with some slight modifications:
- uses NRF24L01 radios instead of bluetooth to Nunchuk
- uses the pin mappings of my CNC shield whereas he directly wired to his DRV8825 drivers
- added incr/decr buttons for P and I and D to help to tune the PID variables.

My code is here:

2 x Arduino Uno (one for vehicle, one for joystick) - $20
1 x CNC shield - $5
2 x DRV8825 Stepper Drivers - $10
1 x MPU6050 Gyro/Accel - $5
2 x NEMA17 1.7A stepper motors - $25
2 x NRF24L01 2.4ghz radio with external antenna - $10
2 x NRF24L01 breakout adapter (converts to 5v) - $5
1 x Funduino Joystick - $10
2 x Wheel+Tire 12mm hex - $15
1 x Matek Duo power supply (12v for motors, 5v for Arduino) - $20

Everything above can be purchased on Amazon, probably Amazon Prime. If you enter exactly what I have for my description into your Amazon search you should be able to find the product.

2 x 3d printed wheel adapters

1 x 3d printed Kobalt battery adapter

The controller code is also at the link above.

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Upgrade LM293D Motor Controller 
Tuesday, May 9, 2017, 12:02 AM - Robots, Devices, Tutorials
Posted by Administrator

Upgrade an LM293D Motor Controller

The lm293d is only rated for around 600ma of continuous current. To increase that greatly, swap out the chip, and stack the chips to double the current handling. The sn75441one chip is rated at 1 amp, 2 amps peak. Stacking them gives 2 amps, 4 amps peak (though I wouldn't recommend 4 amps through it).

How to hotrod a lm293d motor controller

1 - replace the lm293d chips with SN754410NE chips, like these:

2 - stack the SN75441ONE chips pin-for-pin, use thermal tape, and use a heat sink like this: ... Asd08P8HAQ

thermal tape:

This should provide around 2 amps per motor, continuous, over triple the original current handling of the lm293d. Here's what it looks like on the MotoPi motor controller that stacks onto a Raspberry Pi Zero W:

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Robo Roadie 
Sunday, August 14, 2016, 09:31 PM - Robots, Programs
Posted by Administrator

Robo Roadie


I've got this RockNRoller cart thing that's basically a dolly/cart with collapsible arms that can be extended, and is great for hauling speakers and heavy musical equipment around. It's very handy as is, but I don't really use it all that much. What would motivate me to use it more? If it were motorized and remote control from my cellphone, of course!


If you count the cost of the cart then this is a pretty expensive project. I've had the cart for years though. This could work with just about any wheeled cart you can round up, assuming you're willing to figure out how to mount the motors to it.

1 x Rock N Roller R10RT cart - $185
2 x Auto Power Seat Motors - $30
2 x 8" Pneumatic Tires+Wheels - $16
2 x Hobbywing Quicrun 1060 ESC - $40
1 x Arduino Nano - $4
1 x Arduino Nano I/O Shield (not required) - $8
1 x HC-06 Bluetooth Adapter - $8
1 x 5v BEC (not absolutely required) - $8
1 x 12v Battery (I used a 3S Lipo) - $15
1 x Android phone/tablet to control over bluetooth - ???
1 x Blueberry Android App - free

So, total cost not including the cart was about $130. With that particular cart, around $310 I guess.


Here's what I wound up with:

Here's what I started with:

I'll upload a video as soon as I get a chance to video it in action.

So I took off the back wheels and mounted some fairly powerful motors onto it. I used two power seat motors for cars. They're great because:

1. they're cheap (around $15 on Amazon)
2. they're easily powered by 12vdc
3. the housing is not grounded (unlike most power wiper motors), so they're reversible without shorting out via the metal frame.

Here's a link to what I got, though I'd recommend looking for an "Amazon Prime" version if you can find it:

I used a couple of wheels+tires that I got from Freight Harbor. It's 8", supposedly non-marring, and is fairly easy to adapt to the motors I've got by using some hardware from Lowes. I used a 0.5" sleeve to get it to snug down pretty tight on the motor shaft.

An Arduino Nano and a I/O shield handle the logic, and a cheap bluetooth adapter (around $8 on amazon) handles the communications from the controller. I use my Android phone as the controller, and the app Blueberry does a great job of collecting speed/direction via screen presses.

Inexpensive Arduino Nano on Amazon:

The Nano I/O shield:

The bluetooth adapter:

The Blueberry app:

That app "Blueberry" is really cool. It won't work by just installing and pairing it, you have to code for its heartbeat signals. That's a really good thing though. That way, if the Arduino quits responding then the app almost immediately notices it, and it disconnects. Also, the Arduino will know very quickly if the app has disappeared. It helps to keep this Robo Roadie from going berserko and breaking ankles. It's definitely powerful enough to do great harm to an ankle should it get loose.

To drive the motors I used some inexpensive reversible brushed speed controllers. I've used these on several projects and they're reliable and fairly powerful. The Hobbywing Quicrun 1060 - around $20 per wheel.

For power, I use whatever 3S Lipo battery I've got charged up. They can be had for $15 or so from HobbyKing. It runs for a long time on a 5000Mah 3S battery. I also used a separate BEC to get the ~12v down to 5v for the arduino+bluetooth adapter. I could probably use the BEC that's built into the ESCs, but I've pretty much decided to quit trusting ESCs for 5v. Separate BECs are so cheap (around $8), I'd rather just use one and know for certain that I'm going to get around 5v. I used a Dr. Mad Thrust 3A BEC that also has an on/off switch that you can use to turn on/off another device, like headlights. ... ouse_.html

My Arduino code does the following:
- connects to the bluetooth adapter via software serial
- waits for a connection from an external device (Blueberry)
- watches for speed commands, remaps/mixes them, and sends them out to the speed controllers

The code is here:
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Nerf Gun Robot 
Thursday, June 9, 2016, 03:41 PM - Robots, Programs
Posted by Administrator


This 4 wheel drive robot supports RC remote control, a headlight, a 2DOF arm with a gripper, remote Nerf gun firing, 5.8ghz video transmission, and automation via Raspberry Pi (not yet implemented).

Parts List:

4 x Pololu brushed DC gearmotors (2 with encodersj, 2 without)

4 x Pololu wheels

2 x Pololu motor mounting brackets (1 pair/pkg)

1 x Ion Motion 2x15A Roboclaw motor controller

Aluminum angles from Lowes - as needed to build frame.

2 x misc. servos for arm

1 x misc. servo for Nerf gun trigger

2 x misc. aluminum servo brackets (with bearing)
I can't find the ones that I usually get. I was getting them on ebay for around $4 each.

1 x ~5v headlight that can be turned on and off by simply removing or restoring power. Don't get one that uses a soft switch, because when you apply DC to those, they don't turn on until the button is pressed.

1 x Makeblock gripper

1 x Arduino Nano

1 x Arduino Nano breakout board

1 x Keystudio I2C PWM driver

1 x 5.8ghz video transmitter

1 x 12v camera

1 x Misc dual H Bridge, for controlling headlight and gripper

1 x electric Nerf gun. I used N Strike Elite

1 x 5v BEC for servo power and Arduino

1 x Misc 12v battery for video transmitter, camera, motor controller, and drive motors


Arduino Nano code is on my github:

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Sunday, June 14, 2015, 05:47 PM - Robots
Posted by Administrator


Atticbot is a remote control vehicle thing that I designed to remotely crawl around my attic and inspect the bats that had moved in. It's basically just a couple of continuous-rotation servos attached to a yardstick frame, a battery, an RC receiver, a video transmitter, and a camera.

Parts List:

2 x continuous rotation servos

2 x yardsticks for frame

1 x RC receiver - FrSky somethingorother
1 x RC transmitter - Turnigy 9XR-Pro perhaps
1 x 5.8ghz Video transmitter+camera
1 x 5.8ghz Video receiver/display

I've really skimped on details on this parts list. Email me if you have questions.

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