Let's Make Robots!


Motor control with PID and PWM

Working on adding encoders to my project and could use some resources/help on understanding how to code pulse width modulation (PWM) with Proportional Integral Derivative (PID) to control brushed DC motors. Any help would be wonderful. 


Encoders in a dirty environment


In my quest for a cleaner house, I am building a mopping robot.  I find that if my innovations make my wife's life easier, she is more likely to concur with financial outlays so this is the most recent project.

Rover 5: how to measure distance with one encoder output

I recently bought a Rover 5, Arduino Uno and 2A Motor Shield and made my first sketches.
I would now like to use the encoders to control the motors and I have a question about that.

I would like to measure distance and am not interested in direction.
That must be possible with one encoder output but how?

Synchronizes a cieling full of UV LEDs to music
This project began as a graduation gift to my sister. I thought it would be cool to install lights in our basement that react to music so that it could be used as a … Read more

Dagu Rover 5 Asymmetrical Encoder Output Problem

I'm having problems with Dagu Rover 5 with asymmetrical encoder outputs.  They do not have a 50% duty cycle and when the two outputs are decoded they don't give the same count going forwards as backwards.  I'm using 74HC14 Schmidt Triggers with a Teensy++ 2.0 and 4x encoder library.  My fix is to count by 1's going forwards and 1.75 backwards.  Is there a way to fix these encoders to have a 50% duty cycle?Dagu Rover 5 Encoder Output

Cheap gearhead motor with built in encoder

I just saw that The Electronic Goldmine has the Faulhaber gearhead motors with built in encoders sold "As Is" for $2.95 (regular $11.95) because the ribon cable may have cuts in it and some motors may not work properly. Still, for the price of a pair at a regular price you get 4 pairs of motors to use in several projects, so I thought I should share. I've used these motors in my MiniEric robot and I'm very happy with them.

Navigate around via ultrasound
Using a
Hi guys! I want to submit to you my first project (and I hope not last). I know this good site for a long time and now I decided to share my robot. Read more

Dagu Rover 5 & Arduino Uno /Help

Hello everyone.

I'm trying to make a robot for experimentation, something i can use in my studies aswell. I'm studying Electronics & Computer engeneering, first year, and i want a platform that i can improve in the years to come. 

I started playing around with LEDs and an arduino some time ago, this week i bought a Dagu Rover 5 with 4 motors and 4 encoders. The problem is i don't have the 4 channel DC motor controller. 

How to keep pixace controlled robot from getting stuck?


I have built my first robot after advice of  LMR start here. So my robot is navigating with help of IR sensor and has those standard geared motors.

 I'm wondering if picaxe can read information from motors if the robot gets stuck. I guess motor makes some noise in such a situation?Can pushing against some obstacle with rubberwheels on harm picaxe?

I would be grateful for any piece of advice!


guide light, conduct air, be tubey
When your project, like mine, needs a tube pipe to fit exactly around something, consider making your own. I could not find anything with the exact inner diameter … Read more

Optical Encoder giving variety of results

I have a QRB 1114 and have done a little experimenting with electrical tape on my wheels.  I "thought" that I had this working before in a different setup, but maybe it was not working "correctly" before.

Simple Optical/Rotary Encoder Generator

Was building a simple Rotary Encoder for the ARP platofrm yesterday. Could not find a simple tool to generate the pattern according to my needs, there were some Postscript based tools but they did not work on Windows.

So here is my little script to generate it ...

PHP Code:

header("Content-type: image/gif");
$size = isset($_GET['size'])?intval($_GET['size']):200;
$size1 = isset($_GET['size1'])?intval($_GET['size1']):0;
$count = isset($_GET['count'])?intval($_GET['count']):10;

Homemade wheel encoder

Basically I just printed out one of these (laser printer recommended):


...And attached it to a wheel (double sided tape recommended).

Then I hooked up one of these (a 2$ IR sensor: QRB1134):


...And attached it to the motor pointing towards the wheel.

Robot position with quadrature encoder

I'm building a robot for environment mapping. It's a simple "start here"-class robot: 2 wheels, 2 dc motors and a range sensor mounted on a servo. I plan to hook it up with my PC 1st by USB and later on by wireless somehow.

I want it to drive around and send the range sensor readings to the PC which in turn will be building a map of the environment. The hard part will be knowing the robot's position relative to it's earlier position(s). I know this would be easy with a GPS or an accelerometer, however I wish to find a more lowtech/DIY solution, so here is my idea:

Gives feedback to your robot brain...
Encoders, Encoders... Encoders can be used to provide feedback info to your pic to let it know what the mechanics of the machine are doing. In the case of this … Read more