How can I fix it?

Im trying to make may arduino play a sequence of notes using a buzzer.

code:

%arduino music

pin = 'D5';

tune = 'eefggfedccdee dd';

beats = [1 1 1 1 1 1 1 1 1 1 1 1 1 2 2 3];
notes = ['c', 'd', 'e', 'f', 'g', ' '];
freq = [262 294 330 349 392 0];

for ii = 1:length(tune)
    playTone(arduino,pin,freq(strcmp(tune(ii),notes)),0.1*beats(ii))
    pause(0.1*beats(ii))
end

output:

>> musicArduino
Error using musicArduino (line 12)
Invalid parameter type. The tone frequency
value must be a scalar double between 0 and
32767 (Hz).

Answer 1

[Walter Roberson]

You strcmp a single character from the tune to the 6 character vector formed by notes. The result will be a scalar false leading to empty freq selection.

Easiest fix is to make notes a cell array instead of a character vector. Remember that ['a', 'b'] means horzcat('a', 'b') which is 'ab'

[Natalio Ramirez]

Then the values assigned to variable freq have nothing to do with the error?

[Walter Roberson]

The values assigned to freq had nothing to do with the error. The problem was that you were ending up passing [] in the frequency location, and [] is not a scalar double .

Change

notes = ['c', 'd', 'e', 'f', 'g', ' '];

to

notes = {'c', 'd', 'e', 'f', 'g', ' '};