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quartiq / stabilizer

Firmware and software for the Sinara Stabilizer module with high speed, low latency ADC/DAC data processing and powerful DSP algorithms in between
http://quartiq.de/stabilizer/
Apache License 2.0
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[v1.3.2 hw] DAC8831IBD noise #931

Closed MorganTL closed 4 months ago

MorganTL commented 4 months ago

Flashed ff2c2c1 on v1.3.2 hardware, both DAC8831IBD outputs are very noisy.

Test setup

With ADC input

noisy

Using signal_generator

noisy_sig_gen

Related issue

jordens commented 4 months ago

Certainly doesn't look like a DAC issue and potentially not even a software issue then. Could you please check the ADC data?

jordens commented 4 months ago

And show me platform service

jordens commented 4 months ago

And the manufacturer will aid you with hardware issues. Who is it?

ryan-summers commented 4 months ago

The linked issue implies this was built by Creotech, and the further information indicates this is indeed a DAC issue, as replacement of the DAC8831 with the AD5542A was claimed to have resolved this issue.

It seems like there is a concern that SPI timing characteristics may not be being met with the new DAC, but I don't see a significant difference between the two while taking a cursory glance.

jordens commented 4 months ago

@ryan-summers I'd be more cautious about those conclusions. I don't see how the issue implies manufacturer. The fact that excluding the ADC also makes the issue go away points elsewhere. Please let @MorganTL respond to my requests.

MorganTL commented 4 months ago

And the manufacturer will aid you with hardware issues. Who is it?

The card is a production sample from us (M-labs). And I am the electronics engineer who debugged the hardware issue. I raised an issue here because @gkasprow suggested it maybe an SPI issue.

Certainly doesn't look like a DAC issue and potentially not even a software issue then. Could you please check the ADC data? And show me platform service

Unfortunately, we returned the production sample to our PCBA provider for rework.

jordens commented 4 months ago

Non-reproducible then. Feel free to reopen when you get it back, can reproduce it, and have the requested info.