AHT20TEMP(4) FreeBSD Kernel Interfaces Manual AHT20TEMP(4)
NAME
aht20temp - Driver for Guangzhou Aosong AHT20 sensor chip via I2C bus
SYNOPSIS
aht20temp* at iic? addr 0x38
DESCRIPTION
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.
SYSCTL VARIABLES
The following sysctl(3) variables are provided:
hw.aht20temp0.ignorecrc
If set, the crc calculation for %RH and temperature will be
ignored.
hw.aht20temp0.debug
If the driver is compiled with AHT20_DEBUG, this node will appear
and can be used to set the debugging level.
hw.aht20temp0.readattempts
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.
SEE ALSO
envsys(4), iic(4), envstat(8), sysctl(8)
HISTORY
The aht20temp driver first appeared in NetBSD 10.0.
AUTHORS
The aht20temp driver was written by Brad Spencer <
[email protected]>.
FreeBSD 14.1-RELEASE-p8 November 15, 2022 FreeBSD 14.1-RELEASE-p8