Let's Make Robots!


Trouble with servos!

I’m working on a robot that’s supposed to place dominoes in a track. As part of the design, there’s an arm that grabs and places the dominoes.

Continuously Rotating Servos

I have a pair of servos that were modded to rotate continuously about a year ago. I've been trying to make them rotate with the command:

servo 0, 1 : servo 1, 1

but I find that this does nothing but make the servos twitch. However, when I use:

servo 0, 1 : servo 1, 1

wait 2

the servos rotate clockwise for two seconds. Furthermore, when I use:

servo 0, 2 : servo 1, 2

wait 2

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.

Continuous Rotation Servo & Picaxe

Ok, so I finally got all my gear set up to build robot numero uno, but Im goin friggin nuts trying to control my continuous rotation servos from parallax. Im using a picaxe 18x to produce the code, but no matter what pulsout or servo commands I use, my servo's only go clockwise.I NEED them to be able to go counterclockwise  for my differential drive train to work right. I have read every post on LMR about servos and have tried a lot. I have read their parallax data sheet and that they should respond based upon the pulse width, but no go.