Fermentation mutex

Good Morning,

I have recently just started brewing beer again after moving home. I have had to re-install brewblox on to a new RPi 3 after a what appears to be file system corrumption. No problems installing the software or reconnection to the Spark 3, however i had to re-flash the spark 3 with new firmware to allow it. work with the latest Brewblox software. The issue I am having is that the beer temp is sitting at 19.3 degrees and the profile is calling for 20 degrees, this has been like this for the past 18 hours. When I check the Heat pin seems to be under the control of the Mutex, my understand was that the mutex was to prevent the compressor from being switch on and off to frequently along with not allowing heat and cool to be running at the same time.

Grateful for any advice

Stuart Mearns

It may be in the lockout period right now, where if the compressor has been active, it prevents the heater (but not itself) from switching on for some time after it has released the mutex.

If you open the heater digital actuator block, this countdown should be shown if active.

18 hours is rather long though. Could you please post a screenshot of your fermentation graph with digital actuator state included?

Thanks for quick response. I can confirm that the mutex is active on the heat digital actuator block, with about 12 mins remaining. I thought that it would have achieved the target temp after 18 hours. Am I being too impatient? I have not seen (or noticed this in past brews).

Good News. I have solved the issue. It is down to human error I am afraid. When putting the system back together, I had transposed the beer temp sensor and the chamber temp sensor on the Spark. Doh. Sorry for the bother on a Saturday morning. Everything looks more normal now.


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