eez-open / modular-psu-firmware

Firmware for EEZ Bench Box 3 (BB3)
https://www.envox.eu/eez-bb3/
GNU General Public License v3.0
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DCP405 current readout unstable with noisy load #288

Open brianbienvenu opened 2 years ago

brianbienvenu commented 2 years ago

The front panel current readout for the DCP405 is unstable with a noisy load. This is the shape of the current load waveform, from a stepper motor driver: image It's slightly above 1 kHz, although the DCP405 shows similar effects at many load frequencies.

Here's a short video showing what the DCP405 https://www.dropbox.com/s/emnk0k948xu6vqn/2021-11-02%2017.55.50.mp4?dl=0

Here's a plot of some samples from the start of the video: image

Here's another short video, showing the internal plot on the front panel: https://www.dropbox.com/s/emr0hzxsuwf2spn/2021-11-02%2018.16.18.mp4?dl=0

It seems that the DCP405 has that higher rate data available internally, but isn't doing any low-pass filtering on the front panel output. I guess that any one of those samples can show up on the screen, depending on when a screen update was scheduled.

It would be great if the front-panel samples could be smoothed better, rather than presenting these noisy readouts.

Thanks!