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Based on kernel version 3.13. Page generated on 2014-01-20 22:03 EST.

1	Kernel driver sht21
2	===================
3	
4	Supported chips:
5	  * Sensirion SHT21
6	    Prefix: 'sht21'
7	    Addresses scanned: none
8	    Datasheet: Publicly available at the Sensirion website
9	    http://www.sensirion.com/en/pdf/product_information/Datasheet-humidity-sensor-SHT21.pdf
10	
11	  * Sensirion SHT25
12	    Prefix: 'sht21'
13	    Addresses scanned: none
14	    Datasheet: Publicly available at the Sensirion website
15	    http://www.sensirion.com/en/pdf/product_information/Datasheet-humidity-sensor-SHT25.pdf
16	
17	Author:
18	  Urs Fleisch <urs.fleisch@sensirion.com>
19	
20	Description
21	-----------
22	
23	The SHT21 and SHT25 are humidity and temperature sensors in a DFN package of
24	only 3 x 3 mm footprint and 1.1 mm height. The difference between the two
25	devices is the higher level of precision of the SHT25 (1.8% relative humidity,
26	0.2 degree Celsius) compared with the SHT21 (2.0% relative humidity,
27	0.3 degree Celsius).
28	
29	The devices communicate with the I2C protocol. All sensors are set to the same
30	I2C address 0x40, so an entry with I2C_BOARD_INFO("sht21", 0x40) can be used
31	in the board setup code.
32	
33	sysfs-Interface
34	---------------
35	
36	temp1_input - temperature input
37	humidity1_input - humidity input
38	
39	Notes
40	-----
41	
42	The driver uses the default resolution settings of 12 bit for humidity and 14
43	bit for temperature, which results in typical measurement times of 22 ms for
44	humidity and 66 ms for temperature. To keep self heating below 0.1 degree
45	Celsius, the device should not be active for more than 10% of the time,
46	e.g. maximum two measurements per second at the given resolution.
47	
48	Different resolutions, the on-chip heater, using the CRC checksum and reading
49	the serial number are not supported yet.
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