AHT20TEMP(4) Device Drivers Manual AHT20TEMP(4)

aht20temp — Driver for Guangzhou Aosong AHT20 sensor chip via I2C bus

aht20temp* at iic? addr 0x38

The aht20temp driver provides measurements from the AHT20 humidity/temperature sensors via the envsys(4) framework. The aht20temp addr argument selects the address at the iic(4) bus. The crc validity can be changed through sysctl(8) nodes.

The following sysctl(3) variables are provided:

If set, the crc calculation for %RH and temperature will be ignored.
If the driver is compiled with AHT20_DEBUG, this node will appear and can be used to set the debugging level.
To read %RH or temperature the chip requires that the command be sent, then a delay must be observed before a read can be done to get the values back. The delays are documented in the datasheet for the chip. The driver will attempt to read back the values readattempts number of times. The default is 10 which should be more than enough for most purposes.

envsys(4), iic(4), envstat(8), sysctl(8)

The aht20temp driver first appeared in NetBSD 10.0.

The aht20temp driver was written by Brad Spencer <brad@anduin.eldar.org>.

November 15, 2022 NetBSD 11.0