What read() function with <<1,'uint8'>> arguments returns afterall?
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I'm trying to read data from a serial port.
So, my code is something like this:
ser = serialport('COM2',2400);
ser.DataBits = 8;
ser.StopBits = 1;
ser.ByteOrder = 'big-endian';
data = read(ser,1,'uint8');
My Question: What data type 'data' is?
From what I thought it would be an unsigned integer from 0 to 128.
But then when I make de2bi(data) it shows an error saying: "Error using bi2de>validateInputs (line 44). Expected input number 1, binary vector b, to be nonempty.".
Is perahps read() function returning some kind of data array?!
Thanks for help!
採用された回答
Steven Lord
2020 年 1 月 10 日
When you call the serialport function then call read on the ouput of that function, you're calling this version of the read function. According to that documentation page "For all numeric precision types, data is a row vector of double values. For the text type precision values of 'char' or 'string', data is of the specified type."
But based on the text of the error message you received I suspect Walter is correct, that it is an empty row vector because the serialport object timed out and so didn't return any data.
2 件のコメント
Walter Roberson
2020 年 1 月 10 日
You should test the result of read() for empty so your code will not crash when you go to index the variable.
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