avnish aggarwal / Mbed 2 deprecated Book-PE_09-10_Metronomexx

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Dependencies:   mbed

Fork of Book-PE_09-10_Metronomex by avnish aggarwal

main.cpp@3:0de69a4b8aac, 2013-10-28 (annotated)

Committer:
avnisha
Date:
Mon Oct 28 08:44:02 2013 +0000
Revision:
3:0de69a4b8aac
Parent:
2:d1d15e8c083f 
bug relating to int/float

Who changed what in which revision?

UserRevisionLine numberNew contents of line
robt 0:d7c850cdbc39 1 /*Program Example 9.10: Metronome. Uses Ticker to set beat rate
avnisha 1:733a0de4d34c 2
avnisha 1:733a0de4d34c 3
avnisha 1:733a0de4d34c 4 */
robt 0:d7c850cdbc39 5 #include "mbed.h"
robt 0:d7c850cdbc39 6 #include <stdio.h>
robt 0:d7c850cdbc39 7 Serial pc(USBTX, USBRX);
avnisha 1:733a0de4d34c 8 DigitalIn up_button(p15);
avnisha 1:733a0de4d34c 9 DigitalIn down_button(p16);
avnisha 1:733a0de4d34c 10 DigitalOut redled(LED1); //displays the metronome beat
avnisha 2:d1d15e8c083f 11 Ticker beat_rate;
avnisha 2:d1d15e8c083f 12 PwmOut spkr(p26);
avnisha 2:d1d15e8c083f 13
robt 0:d7c850cdbc39 14 void beat(void);
avnisha 3:0de69a4b8aac 15 float period (1);
avnisha 3:0de69a4b8aac 16 float rate (60);
robt 0:d7c850cdbc39 17
robt 0:d7c850cdbc39 18 int main() {
robt 0:d7c850cdbc39 19 pc.printf("\r\n");
robt 0:d7c850cdbc39 20 pc.printf("mbed metronome!\r\n");
robt 0:d7c850cdbc39 21 pc.printf("_______________\r\n");
robt 0:d7c850cdbc39 22 period = 1;
robt 0:d7c850cdbc39 23 redled = 1; //diagnostic
robt 0:d7c850cdbc39 24 wait(.1);
robt 0:d7c850cdbc39 25 redled = 0;
robt 0:d7c850cdbc39 26 beat_rate.attach(&beat, period); //initialises the beat rate
robt 0:d7c850cdbc39 27 //main loop checks buttons, updates rates and displays
robt 0:d7c850cdbc39 28 while(1){
robt 0:d7c850cdbc39 29 if (up_button ==1) //increase rate by 4
robt 0:d7c850cdbc39 30 rate = rate + 4;
robt 0:d7c850cdbc39 31 if (down_button ==1) //decrease rate by 4
robt 0:d7c850cdbc39 32 rate = rate - 4;
robt 0:d7c850cdbc39 33 if (rate > 208) //limit the maximum beat rate to 208
robt 0:d7c850cdbc39 34 rate = 208;
robt 0:d7c850cdbc39 35 if (rate < 40) //limit the minimum beat rate to 40
robt 0:d7c850cdbc39 36 rate = 40;
robt 0:d7c850cdbc39 37 period = 60/rate; //calculate the beat period
avnisha 3:0de69a4b8aac 38 pc.printf("metronome rate is %f\r\n", rate);
avnisha 3:0de69a4b8aac 39 pc.printf("metronome period is %f\r\n", period);
robt 0:d7c850cdbc39 40 wait (0.5);
robt 0:d7c850cdbc39 41 }
robt 0:d7c850cdbc39 42 }
robt 0:d7c850cdbc39 43
robt 0:d7c850cdbc39 44 void beat() { //this is the metronome beat
robt 0:d7c850cdbc39 45 beat_rate.attach(&beat, period); //update beat rate at this moment
avnisha 2:d1d15e8c083f 46
avnisha 2:d1d15e8c083f 47 // speaker
avnisha 2:d1d15e8c083f 48 spkr.period(1.0/5000);
avnisha 2:d1d15e8c083f 49 spkr=0.5;
avnisha 2:d1d15e8c083f 50
avnisha 2:d1d15e8c083f 51 // led
robt 0:d7c850cdbc39 52 redled = 1;
robt 0:d7c850cdbc39 53 wait(.1);
avnisha 2:d1d15e8c083f 54
avnisha 2:d1d15e8c083f 55 // turn off speaker and led
robt 0:d7c850cdbc39 56 redled = 0;
avnisha 2:d1d15e8c083f 57 spkr = 0.0;
robt 0:d7c850cdbc39 58 }
robt 0:d7c850cdbc39 59