That is the resolution of the sensor. I chose to display the actual value of the sensor, instead of the output of the filter.
This is what is actually measured, without any delay.
Elco, youāre still not using the room temp sensor for anything, correct? Just noticed some weird behavior today with the beta firmware: I opened my garage door for awhile, which quickly warmed the room up, but it actually caused the fridge set point to increase quickly, not decrease. Seemed odd. The beer is fine, it was just unexpected. Default settings with the new firmware and scripts.
Unrelated (and a more problematic issue) I canāt seem to heat and cool on the same profile anymore. Let me explain: Iāve had my BrewPi year now and have done 20-30 batches with the same configuration and havenāt touched my wiring or BrewPi. Worked great. I took a break for a bit in the winter, upgraded to the latest beta firmware recently, and now Iām having a really weird problem. The fridge works perfect (as you can see in the graph above) however whenever it needs heat the signal fails to stay on. Instead it pulses, turning the heater on for 1 second, then off, then on, then off, etc. Iāve ruled out the heater and SSR. How? If I set it to test mode they work perfectly. Also, Iāve swapped ports, cables, SSRs, and everything works perfect, the problem always is directly from the Spark. Everything points back to the Spark not maintaining the relay signal and cutting in and out. If I set it to just heat, or just cool, it works fine. But dual devices loaded of both cool and heat cause one of them to freak out, in this case heat.
This is due to the new PWM outputs. It will puls each 4 seconds with a duty cycle needed to maintain stable temperature.
OK, so sorry for my ignoranceā¦ how do I get back to normal cooling/heating? The cooling seems to work the same as always, I just canāt heat.
The On/Off behavior is normal. It is used to be able to heat gradually, instead of full ON/ full OFF.
Based on your chart:
- Your beer temperature does not follow your fridge temperature quickly. Perhaps you can add a fan to circulate air in the fridge.
- You can increase beer-to-fridge Kp for a higher difference between fridge and beer temperature.
- You should increase Kp for the heater and perhaps increase the period. Then it will heat for longer each cycle. At which temperature difference do you think the heater should be full on? Kp = 100 / diff.
Ah, understood. I missed the whole PWM update change last year which was why I was so confused going back after some time off. Itās a 14gl conical, so beer response time is slow even with a fan, but thatās fine. Now that I understand whatās going on Iāll play with the numbers. Increasing the heater Kp and period definitely the trick. By the way, I realized this means that when Iām lagering in the summer I can have long deep cooling cycles rather short bursty ones, which was a problem last year. Thank you for making that change!
Just one more thought: for a future feature request, it might be useful to have a handful of default profiles available for different types of configurations that are commonly used that youāve seen on the forum. I realize everyone is a little different, but at least having 5 or 6 choices would probably reduce the number of questions you get on configurations and show people how the number configurations should ideally be in different situations. I feel like most people fall into a couple of categories.
2 Likes
+1 for adding some kind of profiles!
Thanks for the assistance Elco, I have to say that holding for 24 hours with no more than 0.1 degress deviation is pretty impressive!
Thatās the best we can do. One bit resolution of the sensor is 0.06 degrees Celsius, so 0.1 degree Fahrenheit. Canāt do better than the sensor resolution!
Your fridge temp setting is lower than the beer, but it is actually heating to maintain that temp due to the lower outside temperature.
This release is stable for me as well. running default settings except that i have changed Beer-to-Fridge proportional gain (Kp) to 10. needed to up it due to fermenting about 60 liters. Got some over / undershoot when changing temperature but not anything alarming. Now it is steady as a rock at 18 degreesā¦
Also did a 2 step mashing test (forgot to save the graph) with recommended settings from mashing thread. Also worked out great with only minimal overshoot.
Now only thing i need is a way to changed between these 2 modes so that i do not need to reconfigure from scratch every time. Best would of course be if both is supported at the same time. I got probes and outputs to have all devices active all the time.
My setup would be.
Fermenting:
2 tempprobes. (beer constant mode)
2 actuators ( heater and cooler)
Mashing;
2 tempprobes (mash constant mode)
1 actuator (heater)
maybe an extra room tempprobe as well.
+1 on this, I just got my BrewPi delivered and planning to use it in the same setup. This would of course we resolved once multiple chambers is available.
1 Like
Running beta version and everything seems fine.
Anyway, I found this:
If you look at the fridge off time, it is about 2 minutes (120 secs), while the Cooler minimum off time is set at the default value of 180 secs
I hope this is due to the logging interval of 30 seconds! Can you set the logging interval to 10 seconds? On the settings tab.
Thanks all for the feedback. I have released the beta as stable now.
Logging interval is set to 10 seconds. I guess it is the default value, as I didnāt change any parameter since I loaded the beta.
Anyway, looking at the logs in csv format, I see a gap between 15:41:05 and 15:42:33
Not sure about the reason for the missing samples, however the apparently too short interval may be due to this gap.
Can you check in the log files whether the script/controller restarted at that time?