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83 lines
2.3 KiB
83 lines
2.3 KiB
Kernel driver sht15 |
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=================== |
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Authors: |
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* Wouter Horre |
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* Jonathan Cameron |
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* Vivien Didelot <[email protected]> |
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* Jerome Oufella <[email protected]> |
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Supported chips: |
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* Sensirion SHT10 |
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Prefix: 'sht10' |
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* Sensirion SHT11 |
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Prefix: 'sht11' |
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* Sensirion SHT15 |
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Prefix: 'sht15' |
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* Sensirion SHT71 |
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Prefix: 'sht71' |
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* Sensirion SHT75 |
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Prefix: 'sht75' |
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Datasheet: Publicly available at the Sensirion website |
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http://www.sensirion.ch/en/pdf/product_information/Datasheet-humidity-sensor-SHT1x.pdf |
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Description |
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----------- |
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The SHT10, SHT11, SHT15, SHT71, and SHT75 are humidity and temperature |
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sensors. |
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The devices communicate using two GPIO lines. |
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Supported resolutions for the measurements are 14 bits for temperature and 12 |
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bits for humidity, or 12 bits for temperature and 8 bits for humidity. |
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The humidity calibration coefficients are programmed into an OTP memory on the |
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chip. These coefficients are used to internally calibrate the signals from the |
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sensors. Disabling the reload of those coefficients allows saving 10ms for each |
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measurement and decrease power consumption, while losing on precision. |
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Some options may be set via sysfs attributes. |
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Notes: |
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* The regulator supply name is set to "vcc". |
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* If a CRC validation fails, a soft reset command is sent, which resets |
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status register to its hardware default value, but the driver will try to |
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restore the previous device configuration. |
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Platform data |
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------------- |
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* checksum: |
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set it to true to enable CRC validation of the readings (default to false). |
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* no_otp_reload: |
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flag to indicate not to reload from OTP (default to false). |
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* low_resolution: |
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flag to indicate the temp/humidity resolution to use (default to false). |
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Sysfs interface |
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--------------- |
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================== ========================================================== |
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temp1_input temperature input |
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humidity1_input humidity input |
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heater_enable write 1 in this attribute to enable the on-chip heater, |
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0 to disable it. Be careful not to enable the heater |
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for too long. |
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temp1_fault if 1, this means that the voltage is low (below 2.47V) and |
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measurement may be invalid. |
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humidity1_fault same as temp1_fault. |
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================== ==========================================================
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