Found the source of the problem, but I'm not sure why it is a problem.
ow_1923.c (OW_w_mem):
ret = CRC16(p, 4 + rest);
if (ret) {
printf("OW_w_mem: crc err1\n");
}
The CRC16 fails, causing the read of temperature and humidity to
fail. I was feeling brave, so I simply changed the CRC16 call to the
following:
ret = 0;
That worked! Both temperature and humidity appear to read back with
reasonable values.
As a little background, this write routine is called as part of
OW_oscillator to make sure the oscillator is enabled before a read
operation (presumably to prevent the latchup condition in this
part). Not sure why the CRC fails, but the write seems to
work. Hopefully someone else can help explain that.
Michael
At 07:57 PM 6/28/2008, Michael D. Petersen wrote:
>What is the latest level of support for the DS1923? The list of
>devices (http://owfs.org/index.php?page=standard-devices) says there
>is no support, but when I plugged one into the bus, it was
>recognized. However, both the temperature and humidity files are
>unreadable (yes, I did make sure the RTC was running). Just curious
>if this is truly the current state of things.
>
>Thanks,
>Michael
>
>
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