PWM notes

Page last updated 01 Jul 2011, by Francis Griffiths. 0 replies

  1. include "mbed.h"

class PwmIn { public: PwmIn(PinName p) : _p(p) { _p.rise(this, &PwmIn::rise); _p.fall(this, &PwmIn::fall); _period = 0.0; _pulsewidth = 0.0; _t.start(); }

void rise() { _period = _t.read(); _t.reset(); }

void fall() { _pulsewidth = _t.read(); }

float period() { return _period; } float pulsewidth() { return _pulsewidth; } float dutycycle() { return _pulsewidth / _period; }

protected: InterruptIn _p; Timer _t; float _pulsewidth, _period; };

PwmOut x(p21); PwmOut y(p22);

PwmIn a(p5); PwmIn b(p6);

int main() { x = 0.5; y = 0.2; while(1) { printf("a: pw = %f, period = %f\n", a.pulsewidth(), a.period()); printf("b: pw = %f, period = %f\n", b.pulsewidth(), b.period()); wait(2); } }

Please log in to post comments.