Dennis Lee Bieber wrote:
>
>> The really sad thing is that I get a perfectly constructed
>> packet from the reading variable, and that gets butchered when I
>> try to slice it up to pick out individual elements. Since
>> pyserial doesn’t do anything to rearrange the data, then the
>> CMUcam must do the heavy lifting of extracting a perfect packet
>> from the data stream. It’s a real shame I couldn’t use it
>
> More likely it is running fast enough to keep up with the serial
> port, and synchronizes on the "\rM". Your code seems to be reading in
> bursts and somehow losing parts during your processing (which is
> strange, I'd have expected pyserial to buffer some data between reads).
>
> Lacking that, I'd probably end up creating a thread to handle the
> serial port reading, which basically looks like:
>
> while ser.read(1) != "\r": pass #synchronize
> while not Done:
> bfr = []
> while True:
> c = ser.read(1)
> bfr.append(c)
> if c == "\r": break
> queue.put("".join(bfr))
>
> This should result in complete packets (from the "M" to a "\r")
Oh well. readline(eol="\r") will do that much better.
while 1:
data = ser.readline(eol="\r")
args = data.split()
if args[0] == "M":
# command M; do something with args[1:]
elif args[0] == "KK":
# command KK; do something with args[1:]
[.. process other commands ..]
else:
# Invalid command: might be an incomplete
# packet. Just ignore it.
pass
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