groep 16 / Mbed 2 deprecated PES_PWM_Example

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Dependencies:   mbed

main.cpp@0:fca53941e5d5, 2018-09-18 (annotated)

Committer:
Gijsvanoort
Date:
Tue Sep 18 07:52:50 2018 +0000
Revision:
0:fca53941e5d5
Child:
1:fd5f5be335b7
Working PWM example in which you can set the frequency and duty cycle

Who changed what in which revision?

UserRevisionLine numberNew contents of line
Gijsvanoort 0:fca53941e5d5 1 // For this example, you need the BioRobotics shield.
Gijsvanoort 0:fca53941e5d5 2 // Connect POT2 (frequency)to A0
Gijsvanoort 0:fca53941e5d5 3 // Connect POT1 (pwm) to A1
Gijsvanoort 0:fca53941e5d5 4 #include "mbed.h"
Gijsvanoort 0:fca53941e5d5 5 #include <math.h>
Gijsvanoort 0:fca53941e5d5 6
Gijsvanoort 0:fca53941e5d5 7 DigitalOut gpo(D0);
Gijsvanoort 0:fca53941e5d5 8 DigitalOut led(LED_RED);
Gijsvanoort 0:fca53941e5d5 9 AnalogIn freq(A0);
Gijsvanoort 0:fca53941e5d5 10 AnalogIn pwm(A1);
Gijsvanoort 0:fca53941e5d5 11 Ticker ReadPotmetersTicker;
Gijsvanoort 0:fca53941e5d5 12 volatile double frequency_Hz=1;
Gijsvanoort 0:fca53941e5d5 13 volatile double pwm_pct = 50;
Gijsvanoort 0:fca53941e5d5 14 volatile int on_time_us; // The time the LED should be on, in microseconds
Gijsvanoort 0:fca53941e5d5 15 volatile int off_time_us;
Gijsvanoort 0:fca53941e5d5 16
Gijsvanoort 0:fca53941e5d5 17 void ReadPotmeterValues(void)
Gijsvanoort 0:fca53941e5d5 18 {
Gijsvanoort 0:fca53941e5d5 19 frequency_Hz = 1 + pow((double)freq.read(),4) * 50; // Frequency ranges from 1 to 50 Hz
Gijsvanoort 0:fca53941e5d5 20 pwm_pct = pwm.read() * 100;
Gijsvanoort 0:fca53941e5d5 21 on_time_us = (int) ((pwm_pct/100.0) * (1.0/frequency_Hz) * 1.0e6);
Gijsvanoort 0:fca53941e5d5 22 off_time_us = (int) (( (100.0-pwm_pct)/100.0) * (1.0/frequency_Hz) * 1.0e6);
Gijsvanoort 0:fca53941e5d5 23 }
Gijsvanoort 0:fca53941e5d5 24
Gijsvanoort 0:fca53941e5d5 25 int main()
Gijsvanoort 0:fca53941e5d5 26 {
Gijsvanoort 0:fca53941e5d5 27 ReadPotmetersTicker.attach(ReadPotmeterValues, 0.1);
Gijsvanoort 0:fca53941e5d5 28
Gijsvanoort 0:fca53941e5d5 29 while (true)
Gijsvanoort 0:fca53941e5d5 30 {
Gijsvanoort 0:fca53941e5d5 31 led = 0; // Turn led on
Gijsvanoort 0:fca53941e5d5 32 wait_us(on_time_us);
Gijsvanoort 0:fca53941e5d5 33 led = 1; // Turn led on
Gijsvanoort 0:fca53941e5d5 34 wait_us(off_time_us);
Gijsvanoort 0:fca53941e5d5 35 }
Gijsvanoort 0:fca53941e5d5 36 }