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mp-se / gravitymon

iSpindle replacement firmware for beer brewing/fermenting
MIT License
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Strange temperature readings #159

Closed Avalonnw closed 11 months ago

Avalonnw commented 1 year ago

Greetings!

I was wondering if I could get some insight into this weird temperature graph I was getting: image image Hardware - iSpindel on Jeffrey board. Latest version of gravmon flashed via brewflasher. Graphs are from Home Assistant.

mp-se commented 1 year ago

Lets see what we can conclude. First I would like to get some information on the configuration of your setup:

  1. What accuracy do you have on the temp sensor (9,10,11 or 12 bits)? or are you using the sensor in the gyro?
  2. How do you send data to HA ?
  3. What is the format template you have used for sending the data ?
Avalonnw commented 1 year ago
  1. I tried it with 12 bits, then switched back to 9. The plots are with 9
  2. MQTT using default template. The only change was with name on the sensor.
mp-se commented 1 year ago

Thanks, I will do a similar setup and see if I can spot any problems. I cant really see how big the difference is in your graphs. Can you check what the min / max values are in the graph so I can validate that compared to the accuracy of the sensor.

There is a big difference in accuracy depending on what resolution is used on the temp sensor. But the increased accuracy comes with a price in conversion time = less battery life.

9 bits = 0.5°C, up to 93 ms 10 bits =0.25°C, up to 187 ms 11 bits = 0.125°C, up to 375 ms 12 bits = 0.0625°C, up to 850 ms

Note! Update the docs with this information.

mp-se commented 1 year ago

Ive done some tests on one of my builds. This first one is 1.5 hours with 9 bits and really stable.

image

This second one is over a few hours with 12 bits accuracy but there are not any real big variation that I can see.

image

Could be that you have an faulty temp sensor or a copy of the dallas original.

Avalonnw commented 1 year ago

It could be. I am not sure though. My values float within 1 degree, from 10.8 to 11.8. At the same time I have a temperature probe from ITC-308 in the wort and it's not showing any of this. Interestingly, when I was doing formula calibration in a separate container, I haven't seen such behaviour. It has started only when I added that long metal probe for the temperature controller. Could it be some sort of interference?

mp-se commented 1 year ago

Strange, could you take it out and run it outside your container to see if there is the same difference / fluctuation in room temperature?

If you measured it in an active fermentation it could be real temperature since the fermentation process generates heat.

Avalonnw commented 1 year ago

Will do, thanks.

On Wed, 16 Aug 2023, 15:40 Magnus, @.***> wrote:

Strange, could you take it out and run it outside your container to see if there is the same difference / fluctuation in room temperature?

If you measured it in an active fermentation it could be real temperature since the fermentation process generates heat.

— Reply to this email directly, view it on GitHub https://github.com/mp-se/gravitymon/issues/159#issuecomment-1680018049, or unsubscribe https://github.com/notifications/unsubscribe-auth/ABXKDUNLZ7JL5ISLCCWU7ZLXVRP6RANCNFSM6AAAAAA3PGWMQE . You are receiving this because you authored the thread.Message ID: @.***>

mp-se commented 1 year ago

This is from one of my fermentations and as you can see the temperature is fluctuating a bit. This was without cooling but even with cooling it will take time to have an effect on a batch.

image

Avalonnw commented 1 year ago

It fluctuates but nothing like the sinewave I'm getting.

mp-se commented 1 year ago

I cannot reproduce the issue, so I would believe this is a hardware related problem.

Leaving this open for now and come back if you have more input that points to a software problem.

Avalonnw commented 1 year ago

Thank you. I'm still getting this zigzag for some reason. Will try a different iSpindel later.

On Wed, 30 Aug 2023 at 00:37, Magnus @.***> wrote:

I cannot reproduce the issue, so I would believe this is a hardware related problem.

Leaving this open for now and come back if you have more input that points to a software problem.

— Reply to this email directly, view it on GitHub https://github.com/mp-se/gravitymon/issues/159#issuecomment-1697630026, or unsubscribe https://github.com/notifications/unsubscribe-auth/ABXKDUIB75NBXVSUSFLJ3A3XXYATLANCNFSM6AAAAAA3PGWMQE . You are receiving this because you authored the thread.Message ID: @.***>

-- Best Regards, Anton Khrapov

mp-se commented 11 months ago

Updated docs, reopen if needed