aht20temp(4) - NetBSD Manual Pages

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AHT20TEMP(4)            NetBSD 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/tem- perature sensors via the envsys(4) framework. The aht20temp addr argu- ment 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 <brad@anduin.eldar.org>. NetBSD 10.99 November 15, 2022 NetBSD 10.99
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