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![Alexander A. Klimov](/assets/img/avatar_default.png)
Rationale: Reduces attack surface on kernel devs opening the links for MITM as HTTPS traffic is much harder to manipulate. Deterministic algorithm: For each file: If not .svg: For each line: If doesn't contain `\bxmlns\b`: For each link, `\bhttp://[^# \t\r\n]*(?:\w|/)`: If neither `\bgnu\.org/license`, nor `\bmozilla\.org/MPL\b`: If both the HTTP and HTTPS versions return 200 OK and serve the same content: Replace HTTP with HTTPS. Signed-off-by: Alexander A. Klimov <grandmaster@al2klimov.de> Link: https://lore.kernel.org/r/20200719175512.60745-1-grandmaster@al2klimov.de Signed-off-by: Guenter Roeck <linux@roeck-us.net>
68 lines
1.6 KiB
ReStructuredText
68 lines
1.6 KiB
ReStructuredText
Kernel driver sht21
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===================
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Supported chips:
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* Sensirion SHT21
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Prefix: 'sht21'
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Addresses scanned: none
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Datasheet: Publicly available at the Sensirion website
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https://www.sensirion.com/file/datasheet_sht21
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* Sensirion SHT25
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Prefix: 'sht25'
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Addresses scanned: none
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Datasheet: Publicly available at the Sensirion website
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https://www.sensirion.com/file/datasheet_sht25
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Author:
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Urs Fleisch <urs.fleisch@sensirion.com>
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Description
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-----------
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The SHT21 and SHT25 are humidity and temperature sensors in a DFN package of
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only 3 x 3 mm footprint and 1.1 mm height. The difference between the two
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devices is the higher level of precision of the SHT25 (1.8% relative humidity,
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0.2 degree Celsius) compared with the SHT21 (2.0% relative humidity,
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0.3 degree Celsius).
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The devices communicate with the I2C protocol. All sensors are set to the same
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I2C address 0x40, so an entry with I2C_BOARD_INFO("sht21", 0x40) can be used
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in the board setup code.
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sysfs-Interface
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---------------
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temp1_input
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- temperature input
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humidity1_input
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- humidity input
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eic
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- Electronic Identification Code
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Notes
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-----
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The driver uses the default resolution settings of 12 bit for humidity and 14
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bit for temperature, which results in typical measurement times of 22 ms for
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humidity and 66 ms for temperature. To keep self heating below 0.1 degree
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Celsius, the device should not be active for more than 10% of the time,
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e.g. maximum two measurements per second at the given resolution.
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Different resolutions, the on-chip heater, and using the CRC checksum
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are not supported yet.
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