You must be familiar with Linux and programming if you want to copy this project and bring it to a success.
Is counting bubbles useful ? Probably not but it gives some impression how the yeast is doing, responds to temperture or day-night or show when it is really finished.
To improve the video quality use the Youtube controls: go to full screen mode and increase the quality to 1080p HD.
To count the bubbles I used a Raspberry PI B+ 3 with a GrovePi+ shield from Dexter Industries.
The Raspberry runs Raspbian Linux, downloaded from Dexter Industries (free).
Node-Red is used for the graphical user interface and Python3 to read the sensors.
Data exchange from Python (reading the sensors) to Node-Red is through websockets.
Node-Red does not come with the Dexter Raspbian Linux, websockets support for Python is also missing in Python. Both must be installed (see Python script).
The Sensors are:
BME280 to read temperature, humidity and pressure.
This sensor is read every minut. To read this sensor the SMBUS2 drivers must be installed for Python (see Python3 script).
FC-33 electric motor speed sensor bought from AlieXpress.
This sensor is read with 100Hz. Currently that is fast enough to measure the bubble stream.
The GrovePi+ will allow to connect up to 7 FC-33 (for 7 air locks ).
The Node-Red import file can be downloaded here.
The Python3 script can be downloaded here.