DRV8434SEVM: Motor driver not generating output

Weinan Ji

Part Number: DRV8434SEVM
Other Parts Discussed in Thread: DRV8434S,

Tool/software:

Hello

I am evaluating your DRV8434S solution, and have made software to control it.

I have tested that all the signals are ok, and the SPI communications are also verified. However there is no output generated on the motor side.

I used a logic analyzer to check and verify the Enable, nSleep are both High. The STEP signal is 50% duty cycle, 1kHz.

All the VREF, VSDO are measured 3.3V.

I just wonder even if I don't configure the chip through SPI, I should still be able to generate some output on the motor, right? Since we have pulses on STEP.

We have tried different microstep, current settings, none of them actually worked.

So what could be the root cause?

Thanks in advance!

Best regards

Weinan

over 1 year ago

0 Karan Doshi over 1 year ago

TI__Intellectual 2540 points

Hi Weinan,

Can you share waveforms of the following signals to help us debug:

1. STEP
2. DIR
3. AOUT1
4. (If you have a current probe) Current in AOUT1

Regards,
Karan

0 Weinan Ji over 1 year ago

Prodigy 10 points

Hi Karan,

Thanks for the reply.

I have tried to share the waveform, but this doesn't work here.

I will try to send to you on a private message.

0 Weinan Ji over 1 year ago in reply to Karan Doshi

Prodigy 10 points

There is no current on AOUT1

0 Weinan Ji over 1 year ago in reply to Karan Doshi

Prodigy 10 points

Could it be because of some fault in the initialization we need to clear before running ?

0 Murugavel4637 over 1 year ago in reply to Weinan Ji

TI__Mastermind 44145 points

Hi Weinan,

The title of your post mentions DRV8434SEVM. Have you tried to setup the EVM with the GUI and test with a stepper motor?

In order for the output to be active the device must be awake nSLEEP = 1 wait for 1.2ms, tWAKE time then write to CTRL2, EN_OUT = 1 (SPI write), default is 0. Then when ENABLE pin is logic HIGH the outputs will be enabled. If you did not set CTRL2, EN_OUT =1 there will be no output.

Regards, Murugavel

0 Weinan Ji over 1 year ago in reply to Murugavel4637

Prodigy 10 points

Hi Murugavel,

Thank you, it was because of the EN_OUT.

Now I have the output, but the motor seems struggling and vibrating, but not really moving mechanically.

I can confirm the motor windings are connected correctly.

Could there be any other reasons for the issue? Micro_step, current, or?

Thank you!

Weinan

0 Murugavel4637 over 1 year ago in reply to Weinan Ji

TI__Mastermind 44145 points

Hi Weinan,

Good to know EN_OUT was the issue. What microstep mode were you using? What was the desired full-scale current and what was the VREF voltage input? Is it possible to get coil current waveforms for coil A and coil B? Can you share the schematic? Thank you.

Regards, Murugavel

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DRV8434SEVM: Motor driver not generating output