1 Kernel driver sht3x 2 =================== 3 4 Supported chips: 5 6 * Sensirion SHT3x-DIS 7 8 Prefix: 'sht3x' 9 10 Addresses scanned: none 11 12 Datasheets: 13 - https://sensirion.com/media/documents/213E6A3B/63A5A569/Datasheet_SHT3x_DIS.pdf 14 - https://sensirion.com/media/documents/051DF50B/639C8101/Sensirion_Humidity_and_Temperature_Sensors_Datasheet_SHT33.pdf 15 16 * Sensirion STS3x-DIS 17 18 Prefix: 'sts3x' 19 20 Addresses scanned: none 21 22 Datasheets: 23 - https://sensirion.com/media/documents/1DA31AFD/61641F76/Sensirion_Temperature_Sensors_STS3x_Datasheet.pdf 24 - https://sensirion.com/media/documents/292A335C/65537BAF/Sensirion_Datasheet_STS32_STS33.pdf 25 26 Author: 27 28 - David Frey <david.frey@sensirion.com> 29 - Pascal Sachs <pascal.sachs@sensirion.com> 30 31 Description 32 ----------- 33 34 This driver implements support for the Sensirion SHT3x-DIS and STS3x-DIS 35 series of humidity and temperature sensors. Temperature is measured in degrees 36 celsius, relative humidity is expressed as a percentage. In the sysfs interface, 37 all values are scaled by 1000, i.e. the value for 31.5 degrees celsius is 31500. 38 39 The device communicates with the I2C protocol. Sensors can have the I2C 40 addresses 0x44 or 0x45 (0x4a or 0x4b for sts3x), depending on the wiring. See 41 Documentation/i2c/instantiating-devices.rst for methods to instantiate the 42 device. 43 44 Even if sht3x sensor supports clock-stretch (blocking mode) and non-stretch 45 (non-blocking mode) in single-shot mode, this driver only supports the latter. 46 47 The sht3x sensor supports a single shot mode as well as 5 periodic measure 48 modes, which can be controlled with the update_interval sysfs interface. 49 The allowed update_interval in milliseconds are as follows: 50 51 ===== ======= ==================== 52 0 single shot mode 53 2000 0.5 Hz periodic measurement 54 1000 1 Hz periodic measurement 55 500 2 Hz periodic measurement 56 250 4 Hz periodic measurement 57 100 10 Hz periodic measurement 58 ===== ======= ==================== 59 60 In the periodic measure mode, the sensor automatically triggers a measurement 61 with the configured update interval on the chip. When a temperature or humidity 62 reading exceeds the configured limits, the alert attribute is set to 1 and 63 the alert pin on the sensor is set to high. 64 When the temperature and humidity readings move back between the hysteresis 65 values, the alert bit is set to 0 and the alert pin on the sensor is set to 66 low. 67 68 The serial number exposed to debugfs allows for unique identification of the 69 sensors. For sts32, sts33 and sht33, the manufacturer provides calibration 70 certificates through an API. 71 72 sysfs-Interface 73 --------------- 74 75 =================== ============================================================ 76 temp1_input: temperature input 77 humidity1_input: humidity input 78 temp1_max: temperature max value 79 temp1_max_hyst: temperature hysteresis value for max limit 80 humidity1_max: humidity max value 81 humidity1_max_hyst: humidity hysteresis value for max limit 82 temp1_min: temperature min value 83 temp1_min_hyst: temperature hysteresis value for min limit 84 humidity1_min: humidity min value 85 humidity1_min_hyst: humidity hysteresis value for min limit 86 temp1_alarm: alarm flag is set to 1 if the temperature is outside the 87 configured limits. Alarm only works in periodic measure mode 88 humidity1_alarm: alarm flag is set to 1 if the humidity is outside the 89 configured limits. Alarm only works in periodic measure mode 90 heater_enable: heater enable, heating element removes excess humidity from 91 sensor: 92 93 - 0: turned off 94 - 1: turned on 95 update_interval: update interval, 0 for single shot, interval in msec 96 for periodic measurement. If the interval is not supported 97 by the sensor, the next faster interval is chosen 98 repeatability: write or read repeatability, higher repeatability means 99 longer measurement duration, lower noise level and 100 larger energy consumption: 101 102 - 0: low repeatability 103 - 1: medium repeatability 104 - 2: high repeatability 105 =================== ============================================================ 106 107 debugfs-Interface 108 ----------------- 109 110 =================== ============================================================ 111 serial_number: unique serial number of the sensor in decimal 112 =================== ============================================================
Linux® is a registered trademark of Linus Torvalds in the United States and other countries.
TOMOYO® is a registered trademark of NTT DATA CORPORATION.