This code is based on Lewis Loflin's code: https://www.bristolwatch.com/rpi/i2clcd.htm
Adaptions I made:
- using pigpio (http://abyz.me.uk/rpi/pigpio/index.html) instead of wiringPi
- added two more lines for 20x04 LCDs
Instructions to install pigpio: http://abyz.me.uk/rpi/pigpio/download.html
Running this demo:
- download the code
- run make
- run sudo ./i2clcd