Let's Make Robots!

Encoder

Pushing the limits with encoders

This is now a tutorial and can be found here: http://letsmakerobots.com/node/39098

I've been working on some code so that a simple Mini Driver using a lowly ATmega8A can drive two motors with encoders and 8 servos. This may not sound hard at first until you remember that the Servo library kills PWM on the ATmega8. To make matters worse, D2 and D3 are the external interrupt pins but we need them for driving the servos.

Is an Arduino Capable of Reading All Four Rover 5 Quadrature Encoders?

Note: Sorry this post is so long. I used bold text to indicate the main point of the post.

I didn't want to hijack Oddbot's Rover 5 threadso I'm starting this one here in the forum.

In replying to odong's question about the quadrature encoders I stated (among other things):

Encoders in a dirty environment

All,

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?

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

Doing "something" with my encoder inputs.

I have a Rover 5 with the Dagu red back spider and motor controller. I have connected 2 encoders (one on each side) to the motor controller / red back spider. I found the encoder library, and tested it. I now have 2 working encoders and can read the value of them with the example sketches of the encoder library. So far so good.

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. 

Motor with encoder

Hello everyone. My college has some project organised, to introduce mobile robotics to highschools in my country, and they asked me to design a robot which would be used for that. And it needs geared motors with encoders, and since the only thing I ever used was servos, I need help choosing them.

Small stepper motors

Hello LMR,

I need to get two motors which I can control precisely, like in a CNC.

I've been looking for small stepper motors and found these, which Pololu sells:

http://www.pololu.com/catalog/product/1204

They seem to be good but I'm not sure about their speed (I've read somewhere that the are low speed and I would prefer fast motors).

 

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
A quadrature encoder, also known as an incremental rotary encoder measures the speed and direction of a rotating shaft. Quadrature encoders can use different types … Read more

Optical Encoder giving variety of results

Hello,
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.

Picaxe Encoder wheel timing

I am using the code below to monitor 2 encoder wheels connected to (pin4 left motor QRD1114 & pin3 right motor QRD1114) on my latest 28x1 picaxe project . It works fine .

My question is :- how can i calculate how long the code takes to execute?

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;

Servo+QRD1114 Wheel Encoder -- Fail!

I need wheel encoders on my current project. I believe that the gearing of the servo motors combined with the low weight of the robot won't allow the bot to roll by itself very much. Because of that I figure I don't really need full-tilt quadrature encoders. I also only have two of the QRD1114s, and I need two drive units, so each servo only gets one eye.

Homemade wheel encoder

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

encoder_40_s.gif

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

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

qrb.jpg

...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