74 lines
2.8 KiB
ReStructuredText
74 lines
2.8 KiB
ReStructuredText
|
.. SPDX-License-Identifier: GPL-2.0-or-later
|
||
|
|
|
||
|
|
Kernel driver ChipCap2
|
||
|
|
======================
|
||
|
|
|
||
|
|
Supported chips:
|
||
|
|
|
||
|
|
* Amphenol CC2D23, CC2D23S, CC2D25, CC2D25S, CC2D33, CC2D33S, CC2D35, CC2D35S
|
||
|
|
|
||
|
|
Prefix: 'chipcap2'
|
||
|
|
|
||
|
|
Addresses scanned: -
|
||
|
|
|
||
|
|
Datasheet: https://www.amphenol-sensors.com/en/telaire/humidity/527-humidity-sensors/3095-chipcap-2
|
||
|
|
|
||
|
|
Author:
|
||
|
|
|
||
|
|
- Javier Carrasco <javier.carrasco.cruz@gmail.com>
|
||
|
|
|
||
|
|
Description
|
||
|
|
-----------
|
||
|
|
|
||
|
|
This driver implements support for the Amphenol ChipCap 2, a humidity and
|
||
|
|
temperature chip family. Temperature is measured in milli degrees celsius,
|
||
|
|
relative humidity is expressed as a per cent mille. The measurement ranges
|
||
|
|
are the following:
|
||
|
|
|
||
|
|
- Relative humidity: 0 to 100000 pcm (14-bit resolution)
|
||
|
|
- Temperature: -40000 to +125000 m°C (14-bit resolution)
|
||
|
|
|
||
|
|
The device communicates with the I2C protocol and uses the I2C address 0x28
|
||
|
|
by default.
|
||
|
|
|
||
|
|
Depending on the hardware configuration, up to two humidity alarms to control
|
||
|
|
minimum and maximum values are provided. Their thresholds and hystersis can be
|
||
|
|
configured via sysfs.
|
||
|
|
|
||
|
|
Thresholds and hysteris must be provided as a per cent mille. These values
|
||
|
|
might be truncated to match the 14-bit device resolution (6.1 pcm/LSB)
|
||
|
|
|
||
|
|
Known Issues
|
||
|
|
------------
|
||
|
|
|
||
|
|
The driver does not support I2C address and command window length modification.
|
||
|
|
|
||
|
|
sysfs-Interface
|
||
|
|
---------------
|
||
|
|
|
||
|
|
The following list includes the sysfs attributes that the driver always provides,
|
||
|
|
their permissions and a short description:
|
||
|
|
|
||
|
|
=============================== ======= ========================================
|
||
|
|
Name Perm Description
|
||
|
|
=============================== ======= ========================================
|
||
|
|
temp1_input: RO temperature input
|
||
|
|
humidity1_input: RO humidity input
|
||
|
|
=============================== ======= ========================================
|
||
|
|
|
||
|
|
The following list includes the sysfs attributes that the driver may provide
|
||
|
|
depending on the hardware configuration:
|
||
|
|
|
||
|
|
=============================== ======= ========================================
|
||
|
|
Name Perm Description
|
||
|
|
=============================== ======= ========================================
|
||
|
|
humidity1_min: RW humidity low limit. Measurements under
|
||
|
|
this limit trigger a humidity low alarm
|
||
|
|
humidity1_max: RW humidity high limit. Measurements above
|
||
|
|
this limit trigger a humidity high alarm
|
||
|
|
humidity1_min_hyst: RW humidity low hystersis
|
||
|
|
humidity1_max_hyst: RW humidity high hystersis
|
||
|
|
humidity1_min_alarm: RO humidity low alarm indicator
|
||
|
|
humidity1_max_alarm: RO humidity high alarm indicator
|
||
|
|
=============================== ======= ========================================
|