1.. SPDX-License-Identifier: GPL-2.0 2 3Kernel driver sht4x 4=================== 5 6Supported Chips: 7 8 * Sensirion SHT4X 9 10 Prefix: 'sht4x' 11 12 Addresses scanned: None 13 14 Datasheet: 15 16 English: https://www.sensirion.com/fileadmin/user_upload/customers/sensirion/Dokumente/2_Humidity_Sensors/Datasheets/Sensirion_Humidity_Sensors_SHT4x_Datasheet.pdf 17 18Author: Navin Sankar Velliangiri <navin@linumiz.com> 19 20 21Description 22----------- 23 24This driver implements support for the Sensirion SHT4x chip, a humidity 25and temperature sensor. Temperature is measured in degree celsius, relative 26humidity is expressed as a percentage. In sysfs interface, all values are 27scaled by 1000, i.e. the value for 31.5 degrees celsius is 31500. 28 29Usage Notes 30----------- 31 32The device communicates with the I2C protocol. Sensors can have the I2C 33address 0x44. See Documentation/i2c/instantiating-devices.rst for methods 34to instantiate the device. 35 36Sysfs entries 37------------- 38 39=============== ============================================ 40temp1_input Measured temperature in millidegrees Celsius 41humidity1_input Measured humidity in %H 42update_interval The minimum interval for polling the sensor, 43 in milliseconds. Writable. Must be at least 44 2000. 45heater_power The requested heater power, in milliwatts. 46 Available values: 20, 110, 200 (default: 200). 47heater_time The requested operating time of the heater, 48 in milliseconds. 49 Available values: 100, 1000 (default 1000). 50heater_enable Enable the heater with the selected power 51 and for the selected time in order to remove 52 condensed water from the sensor surface. The 53 heater cannot be manually turned off once 54 enabled (it will automatically turn off 55 after completing its operation). 56 57 - 0: turned off (read-only value) 58 - 1: turn on 59=============== ============================================ 60