Home

Welcome to the aht20 wiki!

C++ example

https://github.com/Seeed-Studio/Seeed_Arduino_AHT20/blob/master/src/ATH20.cpp

    unsigned char str[6];
    int index = 0;
    while (Wire.available())
    {
        str[index++] = Wire.read(); // receive a byte as character
    }

    if(str[0] & 0x80)return 0;

    unsigned long __humi = 0;
    unsigned long __temp = 0;

    __humi = str[1];
    __humi <<= 8;
    __humi += str[2];
    __humi <<= 4;
    __humi += str[3] >> 4;

    *h = (float)__humi / 1048576.0;

    __temp = str[3]&0x0f;
    __temp <<=8;
    __temp += str[4];
    __temp <<=8;
    __temp += str[5];

    *t = (float)__temp / 1048576.0 * 200.0 - 50.0;

Elixir equivalent

# 7 bytes (56 bits)
raw_data_from_sensor = <<28, 38, 154, 118, 66, 231, 118>>    
<<_state::8, humi::20, temp::20, _crc::8>> = raw_data_from_sensor   
humiduty_rh   = humi * 100 / 1048576
temperature_c = temp * 200 / 1048576 - 50