Bosch BME680 is a 4-in-1 sensor with temperature, pressure, humidity
and gas sensing capability. It supports both I2C and SPI communication
protocol for effective data communication.
The device supports two modes:
1. Sleep mode
2. Forced mode
The measurements only takes place when forced mode is triggered and a
single TPHG cycle is performed by the sensor. The sensor automatically
goes to sleep after afterwards.
The device has various calibration constants/parameters programmed into
devices' non-volatile memory(NVM) during production and can't be altered
by the user. These constants are used in the compensation functions to
get the required compensated readings along with the raw data. The
compensation functions/algorithms are provided by Bosch Sensortec GmbH
via their API[1]. As these don't change during the measurement cycle,
therefore we read and store them at the probe. The default configs
supplied by Bosch are also set at probe.
0-day tested with build success.
GSoC-2018: https://summerofcode.withgoogle.com/projects/#6691473790074880
Mentor: Daniel Baluta
[1] https://github.com/BoschSensortec/BME680_driver
Datasheet:
https://ae-bst.resource.bosch.com/media/_tech/media/datasheets/BST-BME680-DS001-00.pdf
Note from Jonathan: The compensation functions are 'interesting' and
could do with a tidy up in future. However, they work so we can leave that
for another day.
Cc: Daniel Baluta <daniel.baluta@nxp.com>
Signed-off-by: Himanshu Jha <himanshujha199640@gmail.com>
Signed-off-by: Jonathan Cameron <Jonathan.Cameron@huawei.com>
Add support for CCS811 VOC sensor. This patch adds support
for reading current and voltage across the sensor and TVOC
and equivalent CO2 values.
Scale and offset values have been computed according to datasheet:
- For current: raw value is in microamps
=> 0.001 scale to convert to milliamps
- For voltage: 1.65V = 1023, therefore 1650mV = 1023
=> 1650.0/1023 = 1.612903 scale to convert to millivolts
- For eCO2: raw value range is from 400ppm to 8192ppm.
=> (val - 400) * (100 - 0) / (8192 - 400) + 0 =
(val - 400) * 0.01283367 => offset: -400, scale = 0.012834
to get a percentage value
-For TVOC: raw value range is from 0ppb to 1187ppb.
=> (val - 0) * 100 / (1187 - 0) + 0 = val * 0.0842459 =>
scale = 0.084246 for getting a percentage value
Cc: Daniel Baluta <daniel.baluta@gmail.com>
Cc: Alison Schofield <amsfield22@gmail.com>
Signed-off-by: Narcisa Ana Maria Vasile <narcisaanamaria12@gmail.com>
Signed-off-by: Jonathan Cameron <Jonathan.Cameron@huawei.com>
Add support for the Atlas Scientific pH-SM chemical sensor that can
detect pH levels of solutions in the range of 0-14.
Signed-off-by: Matt Ranostay <mranostay@gmail.com>
Signed-off-by: Jonathan Cameron <jic23@kernel.org>
Add support for AMS iAQ-core continuous and pulsed VOC sensors.
Signed-off-by: Matt Ranostay <mranostay@gmail.com>
Signed-off-by: Jonathan Cameron <jic23@kernel.org>
Add support for VZ89X sensors VOC and CO2 reporting channels in
percentage which can be converted to part per million.
Signed-off-by: Matt Ranostay <mranostay@gmail.com>
Signed-off-by: Jonathan Cameron <jic23@kernel.org>
