29319 Position Controller Problem (M&WK)

Chuck Rice

I have the M&WK (motor & wheel kit) which comes with two 29319 position controllers. I have been working on the right side, and finally have it working. I can transmit a QPOS+motorID command to it and it responds with the position. This shows on the oscilloscope and I can see all three bytes, and if the wheel moves, the scope shows bits in the return bytes changing with the position. And the data sent back to my terminal shows the correct position values.

So far so good.

Now that I have the right motor working, I thought it would be good to have two wheels work, so I plugged in the second board. I get nothing. On the scope, I see the QPOS+motorID byte sent, but no response, and the code hangs waiting for the answer bytes. I thought that I might have the motorID wrong, so I tried them all (1,2,3,4). No Joy. I checked the +5 volt pin against the ground on the propeller. Perfect +5.04. so I tore it apart, disconnected motor 1, and connected the cable directly to motor 2, setting the jumpers back to the 1 position. No Joy. Same result.

So at the moment, it looks like I might have a bad board. The question is: How can I test the board? Are there any signals that would indicate that it is indeed alive?

NOTE: I do not have the HB25s. I am only using the position controller as an encoder.

dandreae

If I understand correctly you have two boards and one that works and the other does not?· If so, I suggest taking voltage measurements from the good board and comparing them to the other board in order to troubleshoot the problem.

Regards,

Dave





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Dave Andreae

Parallax Tech Support·

Chuck Rice

Thanks, but I already sent it in to you. -CHuck-