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