HB-25 Motor controller not functioning correctly

navila17

Hello,

I have been using a HB-25 motor controller with my propeller demo board. Once I figured out how t communicate with it correctly, it was working ok. But now I go to try it out this morning and it is acting funny. So I decide to just send specific pulses to it and read what it does on a multi-meter. For some reason it will only put out 0 volts, or 100% negative or positive, no matter what pulse I send to it. For example, if I send a 1.250ms pulse, this should put out half power, but it puts out the full 100% voltage. It seems to be unrelated to voltage as I am using a variable power supply and tried with a few voltages.

I have tried power cycling and redoing all the wires/connections a few times already and it doesn't help.

Is it pretty much just broken? Or does anyone think there is a way to fix it?

Thanks,
Nick

Ken Gracey

Try powering up the microcontroller first, then the HB-25. Did this solve the problem?

These little guys are finicky in this way. See page 5 of the product docs.

And if it's actually broken, no worries - we'll replace it.

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Ken Gracey
Parallax Inc.

Follow me at http://twitter.com/ParallaxKen for some insider news.

navila17

Thanks for the reply. Yes I do always try to start the micro controller first, doesn't seem to help. It was working yesterday, then this morning I didn't change anything at all but now I am getting these wrong voltages. So I guess it is broken. How do I go about getting it replaced? I've never had to return anything from Parallax yet, I guess that's pretty good on your part. If it is better, you can just email me back at nickavila1@gmail.com

Thanks a lot,
Nick

JonnyMac

Keep in mind that the output is PWM'd, so checking with a multimeter is not going to be helpful. For a real test you'll need to connect a 'scope to compare the duty-cycle output with the command that you're sending.

Also, the HB-25 has its own initialization period; are you following the start-up protocol to monitor the command line (for its ready state) before you attempt to send pulses to the device?

If you do have a bad device you'll need to call Parallax.

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Jon McPhalen
Hollywood, CA