Victor Szultka / Mbed 2 deprecated 2_4_Speaker

Simulated fire alarm response, with increasing tempo and lowering tone on each repetition

Dependencies:   mbed

main.cpp@0:0651c91d96ca, 2020-07-31 (annotated)

Committer:
saltire78
Date:
Fri Jul 31 13:05:58 2020 +0000
Revision:
0:0651c91d96ca
online posting

Who changed what in which revision?

UserRevisionLine numberNew contents of line
saltire78 0:0651c91d96ca 1 #include "mbed.h"
saltire78 0:0651c91d96ca 2
saltire78 0:0651c91d96ca 3 DigitalIn fire(p14);
saltire78 0:0651c91d96ca 4 PwmOut spkr(p26);
saltire78 0:0651c91d96ca 5 AnalogIn pot1(p19);
saltire78 0:0651c91d96ca 6
saltire78 0:0651c91d96ca 7 float freqmin = 2000.0; // initialising the low frequency range
saltire78 0:0651c91d96ca 8 float freqmax = 10000.0; // initialising the high frequency range
saltire78 0:0651c91d96ca 9 float freqchange = 100; // initialising the frequency change per tone
saltire78 0:0651c91d96ca 10 float freqperiod = 1.0; // initialising the output tone
saltire78 0:0651c91d96ca 11 float speakervol = 0.5; // initialising the PWM output
saltire78 0:0651c91d96ca 12 float tonelength = 0.3; // initialising the time each tone will hold
saltire78 0:0651c91d96ca 13
saltire78 0:0651c91d96ca 14 int main()
saltire78 0:0651c91d96ca 15 {
saltire78 0:0651c91d96ca 16 while (1) {
saltire78 0:0651c91d96ca 17 for (float i=freqmin; i<freqmax; i+=freqchange) {
saltire78 0:0651c91d96ca 18 spkr.period(freqperiod/i); // PWM output frequency
saltire78 0:0651c91d96ca 19 spkr=speakervol; // output volume
saltire78 0:0651c91d96ca 20 wait(tonelength); // length of each tone
saltire78 0:0651c91d96ca 21 }
saltire78 0:0651c91d96ca 22 spkr=0.0;
saltire78 0:0651c91d96ca 23 freqperiod += 1.0; // tone sound will deepen with each repetition
saltire78 0:0651c91d96ca 24 tonelength -= 0.05; // tone sound will shorten with each repetition
saltire78 0:0651c91d96ca 25
saltire78 0:0651c91d96ca 26 while(pot1.read() < 0.5) {} // this uses the pot to control the program
saltire78 0:0651c91d96ca 27 }
saltire78 0:0651c91d96ca 28 }