MATLAB: How to read multiple sensors through the serial.

arduinoMATLABserial

Hi guys
I hope you can help me.
I have connected 4 force sensors to an Arduino, and I´m sending the data to the serial port simultanious – no problems so far.
Now I would like Matlab to read the serial and plot 4 graphs, 1 from each sensor.
The data in the serial are organized in 8 coloums with a description and the value for each sensor.
My problem is, that I dont know how to seperate the serial so each of the four dataset is placed in its own variable so I afterwards can make the plots.
This is my code:
clear all
clc
arduino=serial('COM4','BaudRate',9600);
fopen(arduino);
x=linspace(1,100);
for i=1:length(x);
y(i)=fscanf(arduino,'%f'); 
end
fclose(arduino)
This very basic code only reads the first "coloum" in the serial – how do I add the other coloum, so I can get that data as well?
I appreciate any help 🙂
Best regards Kasper

Best Answer

numcols = 8;
y = zeros(length(x), numcols);
for k = 1 : numcols
  for i=1:length(x);
    y(i, k)=fscanf(arduino,'%f'); 
  end
end
plot(y);
Note: this depends upon all of the data for one sensor being consecutive on the serial port, but the way you describe it you have one data value for each sensor before proceeding to the next data value for the first sensor, and so on. I think it should probably be more like,
numcols = 8;
y = zeros(length(x), numcols);
fmt = repmat('%f', 1, numcols);
for i=1:length(x);
  y(i, :) = fscanf(arduino, fmt); 
end
plot(y);
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