SCORBOT ER V controller

Russ Ferguson

The back of N&V said that the Propeller has 2 counters for each prop. How easy would it be to configure 5 independent up-down counters for absolute positioning of encoders on gear motors?

The class I teach was given a SCORBOT arm with out the controller.
http://www.intelitekdownloads.com/Manuals/Robots/ER_V_plus_manual_100016.pdf

I have a Propeller on the Wulfden board and would appreciate help from this group to make a controller for the SCORBOT arm.

Timmoore

It looks from the manual the encoders are quadrature encoders. There is software available that supports upto 16 encoders, take a look at http://obex.parallax.com/objects/24/

Russ Ferguson

Thank you for the help. Looks like I learn about quad encoders. What is a two bit grey code, is it the same as having 2 opto interupters 90 degrees out of phase?

Russ Ferguson

Thank you for the help. Looks like I learn about quad encoders. What is a two bit grey code, is it the same as having 2 opto interupters 90 degrees out of phase?

Chad George

Since the 2 bit grey code sequence is:
00
01
11
10

I think this is just another way of saying its 2 square waves 90 degrees out of phase.

Timmoore

Correct, you probably need to check the voltages since I didn't see that in the manual. the prop wants 3.3V but 5V can be connected as long as you run it through a 1K inline resistor. The thing I couldn't tell is whether the emittor is powered from the controller or not, you probably need to follow the encoder wiring and work out whats expected. Also with the output, it could be 0/5V or it could be open collector so you need a pull-up resistor. Take a look and see if you can find a part number on the opti isolators.
You haven't mentioned the motors - the manual says 12V motor though the controller drives them at 24V. So the thing to work out is the current draw.