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