sht4xtemp
—
Driver for Sensirion SHT40/SHT41/SHT45 sensor chip via I2C
bus
sht4xtemp* at iic? addr 0x44
The sht4xtemp
driver provides measurements from the
SHT40/SHT41/SHT45 humidity/temperature sensors via the
envsys(4) framework. The
sht4xtemp
addr argument selects
the address at the iic(4) bus. The
resolution, heater controls and crc validity can be changed through
sysctl(8) nodes.
The following sysctl(3) variables
are provided:
hw.sht4xtemp0.resolutions
- Lists the resolutions supported by the driver and chip.
hw.sht4xtemp0.resolution
- Set the resolution, or number of bits, used for %RH and temperature. Use
one of the strings listed in
hw.sht4xtemp.resolutions
.
hw.sht4xtemp0.ignorecrc
- If set, the crc calculation for %RH and temperature will be ignored.
hw.sht4xtemp0.heateron
- Turn the heater on and off. Please note that the heater is turned on right
before the measurement and runs for a pulse width of time. Then the
measurement is taken and the heater is turned off. There is no way to keep
the heater running with this chip.
hw.sht4xtemp0.heaterstrength
- From 1 to 3, the amount of energy put into the heater. The higher the
number, the more power used.
hw.sht4xtemp0.heaterpulses
- Lists the valid heater pulses supported by the driver and chip.
hw.sht4xtemp0.heaterpulse
- Set the heater pulse length. Use one of the strings listed in
hw.sht4xtemp.heaterpulses
.
hw.sht4xtemp0.debug
- If the driver is compiled with
SHT4X_DEBUG
, this
node will appear and can be used to set the debugging level.
hw.sht4xtemp0.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.
The sht4xtemp
driver first appeared in
NetBSD 10.0.