Let's Make Robots!

quadrature

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):

My Persistent Brain - Rover 5

This blog entry is my persistent auxillary brain for robotics stuff.

Motors:

Can't generally run a DC Motor from an Arduino because motors draw too much current and it would fry the board.  So the Arduino needs to provide logic controlling an external power supply.

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

Hack your servo v 2.00 – Add 10-bit incremental / absolute encoder feedback to your hobby servo

Modified continuous-rotation servos are used extensively by roboticists due to their small form-factor, enclosed motor-gearbox, ease of mounting and high-availability. Some users keep the original drive electronics and the potentiometer feedback element but this approach allows for limited position control and velocity control / profiling. Others tend to remove them and use external control/drive boards and custom-made encoders. Ideally one would prefer to have the feedback element and the new drive electronics enclosed inside the servo.

An advanced line follower with quadrature encoders, MicroSD Fat32 recording and more
Using a
This is a bot I built a few years ago when I wanted to start learning robotics. More images here. Its based on the Atmel Mega644P MCU and has an dual H-Bridge … Read more

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: