The objective of the blub-o-meter is to measure fermentation intensity on a fermentation lock by counting the number of bubbles. Reads from a LSM6DS3 accelerometer and converts it to bubbles/time and finally sends this imformation to a server.

• Raspberry Pi 3 (any version is fine)
• LSM 6DS3 accelerometer

• configure i2c interface see instructions by adafruit
  • sudo apt-get install -y python3-smbus i2c-tools
  • sudo raspi-config then Advanced Options->I2C->Yes
  • test I2C using sudo i2cdetect -y 1(or sudo i2cdetect -y 0 on a 256MB Raspberry Pi Model B)

• Adafruit Python GPIO Library see instructions on github -sudo apt-get update -sudo apt-get install build-essential python3-pip python3-dev python3-smbus git -cd externals -git clone https://github.com/adafruit/Adafruit_Python_GPIO.git -cd Adafruit_Python_GPIO -sudo python3 setup.py install

The values are saved as unsigned little endian values, except for the acceleration values, which are signed.

• Header:
  • Magic number 0xb100bb100b (5 bytes)
  • Format version (currently 0x000000, 3 bytes)
  • Start timestamp (Unix timestamp in ms, 8 bytes)
• Any number of entries, each of the following format:
  • Timestamp (# ms since start timestamp, 4 bytes, may overflow)
  • Raw x, y and z acceleration values (2 bytes each)