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Diffstat (limited to 'Documentation/w1/slaves/w1_ds2438.rst')
| -rw-r--r-- | Documentation/w1/slaves/w1_ds2438.rst | 19 |
1 files changed, 18 insertions, 1 deletions
diff --git a/Documentation/w1/slaves/w1_ds2438.rst b/Documentation/w1/slaves/w1_ds2438.rst index a29309a3f8e5..4fa671fbc93f 100644 --- a/Documentation/w1/slaves/w1_ds2438.rst +++ b/Documentation/w1/slaves/w1_ds2438.rst @@ -22,7 +22,7 @@ is also often used in weather stations and applications such as: rain gauge, wind speed/direction measuring, humidity sensing, etc. Current support is provided through the following sysfs files (all files -except "iad" are readonly): +except "iad" and "offset" are readonly): "iad" ----- @@ -44,6 +44,23 @@ Internally when this file is read, the additional CRC byte is also obtained from the slave device. If it is correct, the 8 bytes page data are passed to userspace, otherwise an I/O error is returned. +"page1" +------- +This file provides full 8 bytes of the chip Page 1 (01h). +This page contains the ICA, elapsed time meter and current offset data of the DS2438. +Internally when this file is read, the additional CRC byte is also obtained +from the slave device. If it is correct, the 8 bytes page data are passed +to userspace, otherwise an I/O error is returned. + +"offset" +-------- +This file controls the 2-byte Offset Register of the chip. +Writing a 2-byte value will change the Offset Register, which changes the +current measurement done by the chip. Changing this register to the two's complement +of the current register while forcing zero current through the load will calibrate +the chip, canceling offset errors in the current ADC. + + "temperature" ------------- Opening and reading this file initiates the CONVERT_T (temperature conversion) |