Problem of data missing while reading data through Serial port

7 次查看（过去 30 天）
garima sharma
garima sharma 2022-1-30
I am reading data in ASCII (text) format, which is coming through raspberry pi pico micro-controller. I am fascing the problem of missing of lots of sample data. I am using by default sampling rate of micr-controller 11KHz and baud rate of 115200 but when i am try to acquire even 10Hz sine wave. Data shows only 120 samples in a second for 10Hz sine signal.
My objective is to create a Real time display like a oscilloscope.
how to avoid the problem of data samples missing?
I have figured out that due to "flushinput(s)" command data samples are missing, but if i am not using the buffer clear command then any change in input reflects in recording window after a long dealy.
Also there is a warning message in command window: " Warning:- Unsuccessful read: the input buffer was filled before the terminator reach. How to avoid that as well?
Here the program:
instrreset; % reset all serial ports
clear; close all; clc;
serialPort = 'COM3';
plotTitle = 'Read Throughput';
xLabel = 'Samples'; yLabel = 'Data';
plotGrid = 'on';
min = -5; max = 5; delay = 1e-6;
baudRate = 115200;
buffersize = 1024;
%Define Function Variables
time = 0; data = 0; count = 0;
%Set up Plot
plotGraph = plot(time,data,'-r');
title(plotTitle,'FontSize',18);
xlabel(xLabel,'FontSize',15);
ylabel(yLabel,'FontSize',15);
grid(plotGrid);
dialogBox = uicontrol('Style', 'PushButton', 'String', 'Break Loop','Callback', 'loop_break = false;');
loop_break = true;
%% Open Serial COM Port
s = serial(serialPort,'BaudRate', baudRate,'InputBufferSize',buffersize,'DataBits',8,'Terminator','LF');
fopen(s);
% start stopwatch timer
tic
set(s,'TimeOut', 0.01); % if no data in the buffer matlab will keep trying to read for "Timeout" seconds
%Loop when Plot is Active
while loop_break
%Read Data from Serial as Float
dat = fscanf(s,'%f');
if(~isempty(dat) && isfloat(dat)) %Make sure Data Type is Correct
count = count + 1;
time(count) = toc; %stop the stopwatch and extract time
data(count) = dat(1); %Extract 1st Data Element
set(plotGraph,'XData',time,'YData',data,'LineWidth',2);
axis([0 time(count) min max]);
flushinput(s);
end
%Allow MATLAB to Update Plot
pause(delay);
end
%Close Serial COM Port and Delete useless Variables
if loop_break == 0
fclose(s);
clear count dat delay max min plotGraph plotGrid plotTitle s ...
serialPort xLabel yLabel;
end

请先登录，再回答此问题。

回答（0 个）

类别

在 Help Center 和 File Exchange 中查找有关 Serial and USB Communication 的更多信息

标签

产品


版本

R2016a

Community Treasure Hunt

Find the treasures in MATLAB Central and discover how the community can help you!

Start Hunting!

Translated by