Necessary, but not sufficient:
sudo apt install avr-libc
_________
| U |
Reset (PB5) | 1 8 | VCC (+)
(A3) PB3 | 2 7 | PB2 (A1, SCK, SCL)
(A2) PB4 | 3 6 | PB1 (PWM, MISO)
(-) GND | 4 5 | PB0 (PWM, AREF, MOSI, SDA)
_________
Notes:
* An means "Analog Input n"
* PB means PORTB
* PB5 requires a "fuse" to be set in order to use it.
- clock - setting the clock frequency
- carcoleptic - reduced power consumption
- megaphone