Oscillation following a fresh install

I reinstalled and upgraded to the Jan 2022 release and started seeing oscillation (about a 0.8F amplitude):

Prior to that I’ve had really excellent PID stability (Setpoint unexplainably jumped). I’m fairly confident I was using the default PID settings back then (Brewblox release 2020/12/02 - #3 by Bob_Steers). I looked back at a log I captured before the upgrade (Ferment graph broke on update to 2021/02/25 release - #3 by hexamer) and unfortunately it seems the log only captures the PID parameters for the active blocks and I must have had it in fridge mode.

Currently I’m going through a painfully slow tuning based on a discussion about pidtuner on the discord. So I’m wondering is there something else I’m missing or something that’s changed in recent builds?

I don’t think we changed anything related to this.
If you share the internal PID graphs, I can have a better idea of the cause.

Let me know if there are other parameters you’re looking for:

can you just open each PID, and show the default chart that is included with the block?
If you can screenshot that with the settings included, that would be best.

The graphs at the bottom are the default PID charts zoomed-in to a time-frame similar to above. Ignore the last few hours where the oscillation starts to grow larger. That was me accidentally changing the beer PID values to the default fridge PID values.

As I looked back at my first post on this thread, I do see some oscillation from my previous (2021 system). It’s about 0.4F, but only when controlling near room temperature:

I see you have alternating heating and cooling. You can increase the time the mutex is locked after cooling, that will help. You don’t want the actuators compensating for each other all the time, you want one active at a time.

It will also be easier to tune the settings with one of them active, so they cannot compensate for each other’s overshoot.

The integrator of the heater is above zero on average, but that might be to compensate for the cooler getting in between.

I would make these changes to start:

  • Ti at least 12 hours on both
  • Mutex lock time 6 hours on both