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- Kernel driver w1_ds2423
- =======================
- Supported chips:
- * Maxim DS2423 based counter devices.
- supported family codes:
- W1_THERM_DS2423 0x1D
- Author: Mika Laitio <lamikr@pilppa.org>
- Description
- -----------
- Support is provided through the sysfs w1_slave file. Each opening and
- read sequence of w1_slave file initiates the read of counters and ram
- available in DS2423 pages 12 - 15.
- Result of each page is provided as an ASCII output where each counter
- value and associated ram buffer is outpputed to own line.
- Each lines will contain the values of 42 bytes read from the counter and
- memory page along the crc=YES or NO for indicating whether the read operation
- was successful and CRC matched.
- If the operation was successful, there is also in the end of each line
- a counter value expressed as an integer after c=
- Meaning of 42 bytes represented is following:
- - 1 byte from ram page
- - 4 bytes for the counter value
- - 4 zero bytes
- - 2 bytes for crc16 which was calculated from the data read since the previous crc bytes
- - 31 remaining bytes from the ram page
- - crc=YES/NO indicating whether read was ok and crc matched
- - c=<int> current counter value
- example from the successful read:
- 00 02 00 00 00 00 00 00 00 6d 38 00 ff ff 00 00 fe ff 00 00 ff ff 00 00 ff ff 00 00 ff ff 00 00 ff ff 00 00 ff ff 00 00 ff ff crc=YES c=2
- 00 02 00 00 00 00 00 00 00 e0 1f 00 ff ff 00 00 ff ff 00 00 ff ff 00 00 ff ff 00 00 ff ff 00 00 ff ff 00 00 ff ff 00 00 ff ff crc=YES c=2
- 00 29 c6 5d 18 00 00 00 00 04 37 00 ff ff 00 00 ff ff 00 00 ff ff 00 00 ff ff 00 00 ff ff 00 00 ff ff 00 00 ff ff 00 00 ff ff crc=YES c=408798761
- 00 05 00 00 00 00 00 00 00 8d 39 ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff crc=YES c=5
- example from the read with crc errors:
- 00 02 00 00 00 00 00 00 00 6d 38 00 ff ff 00 00 fe ff 00 00 ff ff 00 00 ff ff 00 00 ff ff 00 00 ff ff 00 00 ff ff 00 00 ff ff crc=YES c=2
- 00 02 00 00 22 00 00 00 00 e0 1f 00 ff ff 00 00 ff ff 00 00 ff ff 00 00 ff ff 00 00 ff ff 00 00 ff ff 00 00 ff ff 00 00 ff ff crc=NO
- 00 e1 61 5d 19 00 00 00 00 df 0b 00 ff ff 00 00 ff ff 00 00 ff ff 00 00 ff ff 00 00 ff ff 00 00 ff ff 00 00 ff ff 00 00 ff ff crc=NO
- 00 05 00 00 20 00 00 00 00 8d 39 ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff crc=NO
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