Raspberry Pi keg fridge monitor

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duckredbeard

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My discussion isn't directly related to Automated Brewing, but it is a technology topic.

I am using a Raspberry Pi to monitor a few things around the brewery:
  1. I have fermentation temperature monitoring using two DHT22 sensors taped to the side of the fermenters. The python script runs every 5 minutes and reports the temperatures to my Android phone. I am using AutoRemote messaging and Tasker, which posts information on my home screen -- and notifications if anything gets out of an acceptable range. This data is logged to a .txt document in the Pi every 5 minutes.
  2. I have keg pressure, temperature, and volume monitoring that reports every 10 minutes. Pressure is monitored at the regulator outlet, a transducer is connected to an ADS1115 and a level shifter to provide pressure readings. Another DHT22 is monitoring the temperature inside the keg fridge. A wheatstone bridge load cell network connected to an HX711 amplifier is monitoring keg weight. This gets raw data and I use known values (empty keg and full keg) to do the math to calculate the remaining percent of the keg. Again, all infomation is sent to the Android phone for display, same as the fermentation temperatures. This data is logged to a .txt document in the Pi every 10 minutes.
I have attached screen shots of my phone and how it displays this information. The information is shown by having Tasker send information to the app MinimalisticText Widgets. On the "Home screen" page, the fermenter temps are displayed in the blue box. The keg fridge information is in the yellow box. Tapping on the keg information box brings up the "Keg Scene" screen for a graphical display of the volume. When put a new keg on, I tap "Reset to full" the keg values return to full (green). The depiction of the keg is in 20 segments to show volume and the colors change as volume decreases. In this case, I am at around 15.9%, which is why it is showing as red.

Apologies to Apple fans, but this sharing of information between Raspberry Pi and my Android phone uses apps that are only available to Android users. The apps are Tasker, Join, MinimalisticText, and AutoRemote. (In fact most of the stuff on that home screen is coming from Tasker!)

I know, this isn't automation. But having that information at my fingertips is very valuable.
 

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