How can I read the whole input buffer of a serial port object?
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Valentino Tomasic
on 22 Jun 2015
Commented: Walter Roberson
on 22 Jun 2015
I am communicating with a device via rs-232 and I would like to read the whole iput buffer of the serial object at once.
What I already tried was:
s = serial('com1');
fopen(s);
fscanf(s,'%f',s.bytesavailable);
So when I run the code I only get the last value instead of the whole input buffer.
Do you have a clue what the issue could be?
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Accepted Answer
Walter Roberson
on 22 Jun 2015
s = serial('com1');
fopen(s);
data = char(fread(s, s.bytesavailable));
sscanf(data,'%f');
Are you certain that you want to try to read floating point text numbers when the buffer might happen to end in the middle of a number?? For text you normally want to work line-by-line (fgetl() or fgets()) or else fscanf() without a count (allowing the scanning to pause for more characters to be received)
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More Answers (1)
Valentino Tomasic
on 22 Jun 2015
1 Comment
Walter Roberson
on 22 Jun 2015
Is the input terminated somehow? linefeed? Or even just a comma between entries? If so then you should be programming a bytesavailablefcn callback. That callback can grab values from the serial port and store them away for a later run of the processing loop. For example you could keep a circular buffer, such as is shown blog or file exchange
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