HYTHYGTEMP(4)

HYTHYGTEMP(4) | Device Drivers Manual | HYTHYGTEMP(4)

# NAME

`hythygtemp` —
Driver for IST-AG HYT-221/271/939 sensor chip via I2C bus

# SYNOPSIS

`hythygtemp* at iic? addr 0x28`

# DESCRIPTION

The `hythygtemp` driver provides measurements from the HYT-221/271/939 humidity/temperature sensors via the envsys(4) framework. The `hythygtemp` addr argument selects the address at the iic(4) bus. The sampling interval can be changed through the sysctl(8) node `hw.hythygtemp0.interval`.

The sensor chips can be reconfigured to respond to other addresses than the default value of 0x28 by external utilities, like for example the pkgsrc/sysutils/hytctl package.

# SYSCTL VARIABLES

The following sysctl(3) variables are provided:

hw.hythygtemp0.interval
  Defines the sensor's sampling interval in seconds. It defaults to 50 seconds.

# SEE ALSO

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

# HISTORY

The `hythygtemp` driver first appeared in NetBSD 7.0.

# AUTHORS

The `hythygtemp` driver was written by Frank Kardel <kardel@NetBSD.org> and Frank Wille ⟨phx@NetBSD.org⟩.

September 9, 2015 | NetBSD 10.0