Thoughts on Updated Motor/Encoder Test and Questions

[madgrizzle]

@dlang

you can’t use single axis move until the encoders are working

I think you can for this test. If I understand things correctly, the singleAxisMove would still turn the motors but the encoder values wouldn’t change so the PID controller would increase the duty cycle to full speed and after the number of movement steps are completed, it would stop the motors. The encoder values still wouldn’t have changed and the result would be a fail just like the current test.

@dlang

the PPR is not an integer (it’s multiplied by the gear ratio, which is not
always an integer)

I am referring to the PPR spec of the encoder… Whatever you call that number of which the stock motor’s encoder equals 7. (fyi, I searched the forum that very question to find out what you called it before I posted the original message )

What is correct chain pitch?

not that I can see, that would be a ratio of 289.7857:1 with 7 PPR (28 encoder steps/rev) has anyone taken a gearbox apart to count the teeth?

@dlang

trying to detect skipped steps is hard, and not something you can do accurately
in a single rotation.

Correct… that’s why I threw out the “one or more revolutions” idea. If you are off on your encoder PPR, I think you could tell from one revolution. But if you suspect maybe the gear ratio is off or you are missing encoder steps, you can tell it to do 50 revolutions…

@dlang

remember, this test is supposed to be a quick test to make sure that things are
plugged in and working, not something to calibrate the encoders or detect missed
steps.

Yes, that’s what that very simple test currently does. I’m suggesting something that gives the user a bit more information and if they want to run a single revolution test, they can and get the same results back as the current test… You could include an ‘advanced motors/encoder test’ option instead, but I don’t see the advantage of separating them other than it might help getting people to agree to a PR.