aht20 communication, no wiringPi

basic i2c communication with aht20 temp/humidity sensor

testing on Orange Pi Zero with Armbian 23.8.1 bullseye, kernel 5.15.93-sunxi

how to compile:

g++ -o aht20 main.c -Wall -O

sample output:

open chip at 0x38 succeeded, fd 3
sent reset command
sent control command
get status register -> 0x18, 00011000
start measurment
measurment done! bytes read: 7
byte [0] -> 0x1C, 00011100
byte [1] -> 0x3B, 00111011
byte [2] -> 0x5E, 01011110
byte [3] -> 0x86, 10000110
byte [4] -> 0x88, 10001000
byte [5] -> 0xB2, 10110010
byte [6] -> 0xD2, 11010010
CRC check -> true
humidity: 23.191071 [%]
temp: 31.674576 [°C]