The combined code looks almost correct, but it requires some minor changes.
- "tic" is called twice, only one is needed before the 1000-sample loop.
- "sound_data(i) = readVoltage" is missing a semicolon which can spam the Command Window.
- Pre-allocate "sound_data/time_data" so the loop doesn’t grow arrays.
- Your first plot uses seconds on the x-axis, but the live plot uses "datenum"—mixing styles isn’t necessary. Use elapsed seconds for both.
- Add simple debouncing so a noisy button doesn’t stop the loop immediately.
clearvars; close all; clc
% 1) Connect to Arduino / Grove
a = arduino('/dev/tty.SLAB_USBtoUART','uno'); % adjust port if needed
configurePin(a,'D6','DigitalInput'); % stop button
% 2) Capture 1000 samples
max_samples = 1000;
sound_data = zeros(1,max_samples);
time_data = zeros(1,max_samples);
tic; % start timer
for i = 1:max_samples
sound_data(i) = readVoltage(a,'A2'); % Grove sound sensor on A2
time_data(i) = toc; % seconds since tic
end
figure;
plot(time_data, sound_data, 'LineWidth', 1);
grid on
xlabel('Time [s]');
ylabel('Voltage [V]');
title('Captured sound (1000 samples)');
% 3) Live feed until button D6 is pressed
figure
h = animatedline('LineWidth',1);
ax = gca; ax.YGrid = 'on'; ax.YLim = [-0.1 5];
xlabel('Time [s]'); ylabel('Voltage [V]');
title('Sound sensor voltage vs time (live)');
tic; % new timer for live view
stop = false;
lastPressT = -Inf; % for debounce
DEBOUNCE = 0.15; % seconds
while ~stop
v = readVoltage(a,'A2');
t = toc;
addpoints(h, t, v)
% show last 15 s
xlim([max(0, t-15), t])
drawnow limitrate
% --- Stop condition on D6 (adjust logic if using pull-down) ---
btn = readDigitalPin(a,'D6'); % HIGH when pressed with pull-up
if btn && (t - lastPressT) > DEBOUNCE
stop = true;
lastPressT = t;
end
end
I hope this helps you.
