motor interference

ChuckT

I am looking for ideas on how to keep motor noise from killing the Propeller.
I am using a 7.2v nicad battery. regulate that down to 5V. Then I have 2 separate 3.3 v regulators.
One for the Propeller and one for the motor.
Even if I run the motor at minimal voltage (using a Pololu smc02B dual H bridge) it stops the process running on the propeller.

The problem only happens if the motor is actual spinning, its not the static load.

SRLM

Are you running the motor on 3.3 v? Why not just use battery voltage? By stepping it down to 5v, then to 3.3v, you loose some power that you could use elsewhere (like to turn the motor shaft.) Doing this might also help your noise problem.

Leon

You could use separate supplies for the motor and controller. Transient suppressors are very useful.

Leon

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Amateur radio callsign: G1HSM
Suzuki SV1000S motorcycle

T Chap

Maybe post your schematic, pics of the pcb. Do you have sufficient bypass caps on the Prop?

When you say "killing the Prop", you mean resetting on low power? Or the noise affects communication from and to the Prop?

ChuckT

Thanks for the ideas, no luck yet.
I attached the schematic.
I tried using 7.2V to power the motor, and adding bypass caps on the prop and at the motor.
I also tried adding big electrolytic cap on the motor supply voltage.

When the motor spins the prop resets.
I have tried pulling up the reset pin.

I appreciate the ideas.

T Chap

I would suggest a beefier power supply as the next thing to try. Low power sounds like your problem.

You need caps on every device, especially .01's near every Prop 3v3 pin, all other Vcc.

BTX

Hi Chuck.

1- Don't abuse with the electrolityc capacitors value, instead add 0.1uf very close propeller and motor power supply.
2- Use separate power suplies as recomended Leon.
3- Try to opto isolate the control pulses from the pack motor/cnotroller to the propeller, and forget.

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Regards.

Alberto.