On Wednesday, September 28, 2016 at 5:15:40 AM UTC-4, Lloyd Kinsella wrote:
>
> I'm pushed out the code to https://github.com/lkinsella/wh2310 hopefully
> it'll help. Any questions just ask and I'll do my best to answer them.
>
lloyd,
does your code actually work? does it properly read current values from
the station? how often do the values change?
the docs say we should expect this for the reply to a READ_RECORD:
nbytes value
1 READ_RECORD
1 size
x data
1 checksum
the code you posted that reads current conditions seems a bit odd.
in the function ReadRecord(), there is a hid_write of 4 bytes with the
READ_RECORD command.
then you do a PerformRead (which is a hid_read), followed by a loop that
does PerformRead (additional hid_read) until you get enough bytes.
the thing that looks odd is the byte accounting from the raw reads.
in the first read, you check for a 0x01 in byte 0, payload_size in byte 1,
0x04 (READ_RECORD) in byte 2, and packet_length in byte 3.
in subsequent reads you skip bytes 0 and 1, but append the rest of the
bytes to the buffer.
on the last read, you skip bytes 0 and 1, and also skip the last byte (the
checksum).
is this a correct description of what ReadRecord is doing?
it seems odd that there is a 0x01 identifier followed by payload size in
each packet (payload size ignored in all but the first packet), plus a
READ_RECORD identifier and packet_size in the first packet, plus a checksum
in the last byte of the last packet.
could you post a few raw sequences with associated decoded values so i can
verify the decoding?
for example, something like this:
[
{'sequence': "01 3b 04 4a ...",
'decoded': {{"label":"in_temp", "value":"25.1 C"},
{"label":"out_humidity", "value":"55"}, ...}
},
{'sequence': "01 45 04 39 ...",
'decoded': {{"label":"in_temp", "value":"22.4 C"},
{"label":"out_humidity", "value":"54"}, ...}
]
when i try to run with an equivalent python implementation on linux using
python-usb, i get garbage from the hardware (or my decoder is not
correct). but at least the hardware is responding now :)
also, i have had no luck reading the eeprom for station parameters and
historical records. i get the same garbage values no matter what address i
request. but that is a different topic...
m
--
You received this message because you are subscribed to the Google Groups
"weewx-user" group.
To unsubscribe from this group and stop receiving emails from it, send an email
to [email protected].
For more options, visit https://groups.google.com/d/optout.
