Serial Receive in ASCII

I am sending and receiving data over serial port the data i am receiving is in ASCII one character after another. i conactenated the characters to get an endless string however I want the last two values from the string which in my case are 42.000 and 2.000

[Ashal Akhtar]

ok so we can apply scan string but not on the endless string but like last 20 characters or something

[Aiswarya]

Do you want to create an endless string (of 42 and 2)? Or do you simply want to obtain the result as 42 and 2?

Answer 1

[Raj]

Hi,

I understand you are trying to exchange data and want to fetch just the last 2 characters of it. Follow the steps stated below to resolve the issue

1. Open the serial port connection using the `serial` function in MATLAB. Assign the specific port to the variable
2. Use the `fread` function to read the signal from the serial port. You can store the value in the buffer as the length of the data is unknown
3. Extract the last 2 characters using MATLAB indexing
4. Use the `fclose` function to close the serial port connection.

As I do not have access to your code, an indicative code is here, adapt it with your code accordingly

s = serialport('COM1');  % Replace 'COM1' with the appropriate port name
fopen(s);

b_Size = 1024;  % Specify the buffer size
data = [];
while s.BytesAvailable > 0
    data = [data; fread(s, b_Size)];
end

lastTwoChars = char(data(end-1:end)');

fclose(s);

Additionally refer to the documentation of fread and Serial receive for better understanding

“fread” - https://www.mathworks.com/help/matlab/ref/fread.html?s_tid=doc_ta

“Serial receive”- https://www.mathworks.com/help/instrument/serialreceive.html?searchHighlight=serial%20receive&s_tid=srchtitle_support_results_1_serial%20receive

I hope this resolves your query!