LXR linux/Documentation/hwmon/sht15.rst

   1Kernel driver sht15
   2===================
   3
   4Authors:
   5
   6  * Wouter Horre
   7  * Jonathan Cameron
   8  * Vivien Didelot <vivien.didelot@savoirfairelinux.com>
   9  * Jerome Oufella <jerome.oufella@savoirfairelinux.com>
  10
  11Supported chips:
  12
  13  * Sensirion SHT10
  14
  15    Prefix: 'sht10'
  16
  17  * Sensirion SHT11
  18
  19    Prefix: 'sht11'
  20
  21  * Sensirion SHT15
  22
  23    Prefix: 'sht15'
  24
  25  * Sensirion SHT71
  26
  27    Prefix: 'sht71'
  28
  29  * Sensirion SHT75
  30
  31    Prefix: 'sht75'
  32
  33Datasheet: Publicly available at the Sensirion website
  34
  35        http://www.sensirion.ch/en/pdf/product_information/Datasheet-humidity-sensor-SHT1x.pdf
  36
  37Description
  38-----------
  39
  40The SHT10, SHT11, SHT15, SHT71, and SHT75 are humidity and temperature
  41sensors.
  42
  43The devices communicate using two GPIO lines.
  44
  45Supported resolutions for the measurements are 14 bits for temperature and 12
  46bits for humidity, or 12 bits for temperature and 8 bits for humidity.
  47
  48The humidity calibration coefficients are programmed into an OTP memory on the
  49chip. These coefficients are used to internally calibrate the signals from the
  50sensors. Disabling the reload of those coefficients allows saving 10ms for each
  51measurement and decrease power consumption, while losing on precision.
  52
  53Some options may be set via sysfs attributes.
  54
  55Notes:
  56  * The regulator supply name is set to "vcc".
  57  * If a CRC validation fails, a soft reset command is sent, which resets
  58    status register to its hardware default value, but the driver will try to
  59    restore the previous device configuration.
  60
  61Platform data
  62-------------
  63
  64* checksum:
  65  set it to true to enable CRC validation of the readings (default to false).
  66* no_otp_reload:
  67  flag to indicate not to reload from OTP (default to false).
  68* low_resolution:
  69  flag to indicate the temp/humidity resolution to use (default to false).
  70
  71Sysfs interface
  72---------------
  73
  74================== ==========================================================
  75temp1_input        temperature input
  76humidity1_input    humidity input
  77heater_enable      write 1 in this attribute to enable the on-chip heater,
  78                   0 to disable it. Be careful not to enable the heater
  79                   for too long.
  80temp1_fault        if 1, this means that the voltage is low (below 2.47V) and
  81                   measurement may be invalid.
  82humidity1_fault    same as temp1_fault.
  83================== ==========================================================
  84