Pioreactor / Pioreactor/pioreactor

[what happened] Periodic signal at 2min / cycle in od reading

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hardware turbidity / OD signal / optics what-happened
Dominant language
Python
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149
Forks
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PR merge metrics
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Description

Screen Shot 2022-01-18 at 11 46 21 AM

If the OD signal looks like this, then likely the LED driver output is saturated and we are basically seeing the 5V rail noise. You can test this by running a CPU intense command (like pio update --app --dev) and seeing the OD drop (pictured above).


Solution is to drop the ir_intensity in the config. In the above graph, the IR intensity was 95%, and I was using v0.1 HAT. After setting the ir_intensity to 45%, this was the result:

Screen Shot 2022-01-18 at 11 53 04 AM

Nice.

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First steps

  1. Read the whole issue, then the project's contributing guide.
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  3. Fork the repository and make your change on a branch.
  4. Open a pull request that references the issue number.

Research direction

Start with the ir_intensity configuration and reproduce the periodic OD signal using the CPU-intensive pio update --app --dev command described in the report. Compare the signal at the reported intensity levels; done means the saturation behavior and the appropriate configuration guidance or change are confirmed.

Written by the indexing model from the issue text.

Assessment

Tech stack
raspberry-pi
Domain
embedded-iot
Issue type
Bug
Difficulty
4/5
Estimated time
3-5 days
Activity status
Stale
Clarity
Needs clarification
Newbie friendliness
30/100

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