diff options
Diffstat (limited to 'Documentation')
| -rw-r--r-- | Documentation/ABI/stable/sysfs-driver-w1_ds2438 | 7 | ||||
| -rw-r--r-- | Documentation/w1/slaves/w1_ds2438.rst | 11 |
2 files changed, 17 insertions, 1 deletions
diff --git a/Documentation/ABI/stable/sysfs-driver-w1_ds2438 b/Documentation/ABI/stable/sysfs-driver-w1_ds2438 index fa47437c11d9..d2e7681cc287 100644 --- a/Documentation/ABI/stable/sysfs-driver-w1_ds2438 +++ b/Documentation/ABI/stable/sysfs-driver-w1_ds2438 @@ -4,3 +4,10 @@ Contact: Luiz Sampaio <sampaio.ime@gmail.com> Description: read the contents of the page1 of the DS2438 see Documentation/w1/slaves/w1_ds2438.rst for detailed information Users: any user space application which wants to communicate with DS2438 + +What: /sys/bus/w1/devices/.../offset +Date: April 2021 +Contact: Luiz Sampaio <sampaio.ime@gmail.com> +Description: write the contents to the offset register of the DS2438 + see Documentation/w1/slaves/w1_ds2438.rst for detailed information +Users: any user space application which wants to communicate with DS2438 diff --git a/Documentation/w1/slaves/w1_ds2438.rst b/Documentation/w1/slaves/w1_ds2438.rst index ac8d0d4b0d0e..5c5573991351 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" ----- @@ -52,6 +52,15 @@ 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) |