0001 Kernel driver sht15
0002 ===================
0003
0004 Authors:
0005
0006 * Wouter Horre
0007 * Jonathan Cameron
0008 * Vivien Didelot <vivien.didelot@savoirfairelinux.com>
0009 * Jerome Oufella <jerome.oufella@savoirfairelinux.com>
0010
0011 Supported chips:
0012
0013 * Sensirion SHT10
0014
0015 Prefix: 'sht10'
0016
0017 * Sensirion SHT11
0018
0019 Prefix: 'sht11'
0020
0021 * Sensirion SHT15
0022
0023 Prefix: 'sht15'
0024
0025 * Sensirion SHT71
0026
0027 Prefix: 'sht71'
0028
0029 * Sensirion SHT75
0030
0031 Prefix: 'sht75'
0032
0033 Datasheet: Publicly available at the Sensirion website
0034
0035 http://www.sensirion.ch/en/pdf/product_information/Datasheet-humidity-sensor-SHT1x.pdf
0036
0037 Description
0038 -----------
0039
0040 The SHT10, SHT11, SHT15, SHT71, and SHT75 are humidity and temperature
0041 sensors.
0042
0043 The devices communicate using two GPIO lines.
0044
0045 Supported resolutions for the measurements are 14 bits for temperature and 12
0046 bits for humidity, or 12 bits for temperature and 8 bits for humidity.
0047
0048 The humidity calibration coefficients are programmed into an OTP memory on the
0049 chip. These coefficients are used to internally calibrate the signals from the
0050 sensors. Disabling the reload of those coefficients allows saving 10ms for each
0051 measurement and decrease power consumption, while losing on precision.
0052
0053 Some options may be set via sysfs attributes.
0054
0055 Notes:
0056 * The regulator supply name is set to "vcc".
0057 * If a CRC validation fails, a soft reset command is sent, which resets
0058 status register to its hardware default value, but the driver will try to
0059 restore the previous device configuration.
0060
0061 Platform data
0062 -------------
0063
0064 * checksum:
0065 set it to true to enable CRC validation of the readings (default to false).
0066 * no_otp_reload:
0067 flag to indicate not to reload from OTP (default to false).
0068 * low_resolution:
0069 flag to indicate the temp/humidity resolution to use (default to false).
0070
0071 Sysfs interface
0072 ---------------
0073
0074 ================== ==========================================================
0075 temp1_input temperature input
0076 humidity1_input humidity input
0077 heater_enable write 1 in this attribute to enable the on-chip heater,
0078 0 to disable it. Be careful not to enable the heater
0079 for too long.
0080 temp1_fault if 1, this means that the voltage is low (below 2.47V) and
0081 measurement may be invalid.
0082 humidity1_fault same as temp1_fault.
0083 ================== ==========================================================
