Kernel driver htu21 =================== Supported chips: * Measurement Specialties HTU21D Prefix: 'htu21' Addresses scanned: none Datasheet: Publicly available at the Measurement Specialties website http://www.meas-spec.com/downloads/HTU21D.pdf Author: William Markezana Description ----------- The HTU21D is a humidity and temperature sensor in a DFN package of only 3 x 3 mm footprint and 0.9 mm height. The devices communicate with the I2C protocol. All sensors are set to the same I2C address 0x40, so an entry with I2C_BOARD_INFO("htu21", 0x40) can be used in the board setup code. This driver does not auto-detect devices. You will have to instantiate the devices explicitly. Please see Documentation/i2c/instantiating-devices for details. sysfs-Interface --------------- temp1_input - temperature input humidity1_input - humidity input Notes ----- The driver uses the default resolution settings of 12 bit for humidity and 14 bit for temperature, which results in typical measurement times of 11 ms for humidity and 44 ms for temperature. To keep self heating below 0.1 degree Celsius, the device should not be active for more than 10% of the time. For this reason, the driver performs no more than two measurements per second and reports cached information if polled more frequently. Different resolutions, the on-chip heater, using the CRC checksum and reading the serial number are not supported yet.