Raspberry gpio

pigpio
https://raspi.tv/2013/rpi-gpio-basics-1-how-to-check-what-rpi-gpio-version-you-have

https://raspi.tv/2013/rpi-gpio-basics-6-using-inputs-and-outputs-together-with-rpi-gpio-pull-ups-and-pull-downs

https://github.com/joan2937/pigpio

http://abyz.me.uk/rpi/pigpio/download.html

pinouts
https://pinout.xyz/pinout/pin7_gpio4#

bristolwatch
https://www.youtube.com/watch?v=1p1rgkslO0U i2c

http://www.bristolwatch.com/rpi/i2clcd.htm

i2c
https://github.com/bradgillap/I2C-LCD-Display

https://www.youtube.com/watch?v=CoC2qDgqmac

https://github.com/HariHend1973/lcd_mpd import SMbus

https://raspberrypi.stackexchange.com/questions/79091/smbus-i2c-sensor-returns-fixed-data

pigpio and i2c
https://i2c-lcd.readthedocs.io/en/latest/installation.html #install i2c_lcd
 * sudo pigpio

links
Raspberry pi