How do I visualise sensor data in MATLAB Online from iPhone app

Hi,

I'm looking to experiment and visually oberve the behaviour of phone sensors (accelerometer etc)

I've managed to stream the data to MATLAB but I'm unsure how to visualise this. Could someone kindly help?

Thank you,

Jeremy

Answer 1

[Suraj]

Hi Jeremy,

It looks like you were succesful in collecting sensor data and you'd like to plot it on MATLAB. I've come up with a script that plots accelerometer data collected from my phone live.

% Start acquiring data from "mobiledev" object "m"
m.Logging = 1;
    pause(0.1);

% Figure for live plot
figure;
hX = animatedline('MaximumNumPoints', 100, 'Color', 'r');
hY = animatedline('MaximumNumPoints', 100, 'Color', 'g');
hZ = animatedline('MaximumNumPoints', 100, 'Color', 'b');
legend('accX', 'accY', 'accZ');
ax = gca;
ax.YGrid = 'on';
ax.YLim = [-20 20];  % Adjust according to your expected range

% Initialize time vector for x-axis
timeVec = [];

% Loop for live plotting while data is being collected
while m.Logging == 1
    % Read acceleration data
    [a, t] = accellog(m);
    
    % If new data is available
    if ~isempty(a)
        % Append new data to the time vector
        timeVec = [timeVec; t];
        
        % Update the plot for each axis
        addpoints(hX, t, a(:, 1));  % X-axis acceleration
        addpoints(hY, t, a(:, 2));  % Y-axis acceleration
        addpoints(hZ, t, a(:, 3));  % Z-axis acceleration
        
        % Update the x-axis limits to focus on last 2 seconds' data
        ax.XLim = [max(timeVec) - 2, max(timeVec)];
        drawnow;
    end
    
    % Pause to control the update rate
    pause(0.1);
end

% Stop logging
m.Logging = 0;

Here's a screenshot of the figure that I was able to plot:

I hope this helps !