101で複数ピンに対応したPWM周波数の変更

　Genuino（Arduino）101で複数pinに対応したPWM周波数の変更を試してみました。

#include "aux_regs.h"
#include "interrupt.h"
#include "conf.h"

#define pinCnt 2      // number of PIN
#define PWMPeriod 300 // Hz

typedef struct {
  unsigned int nbr;
  unsigned int duty;
  unsigned int isState;
  unsigned long highTicks;
  unsigned long lowTicks;
  unsigned long nextTicks;
} pin_t;

unsigned long totalTicks;

pin_t PWMPin[pinCnt];

void setup() {
  PWMPin[0].nbr = 13; //PWM pin assign
  PWMPin[1].nbr = 6; //PWM pin assign

  PWMPin[0].duty = 30; //duty %
  PWMPin[1].duty = 70; //duty %

  totalTicks = 32000000 / PWMPeriod;

  for (int i = 0; i < pinCnt; i++) {
    pinMode(PWMPin[i].nbr, OUTPUT);
    PWMPin[i].isState   = 0;
    PWMPin[i].highTicks = (totalTicks * PWMPin[i].duty) / 100;
    PWMPin[i].lowTicks  = totalTicks - PWMPin[i].highTicks;
    PWMPin[i].nextTicks = 0;
    digitalWrite(PWMPin[i].nbr, PWMPin[i].isState);
  }

  // Timer1 Initialization.
  aux_reg_write(ARC_V2_TMR1_CONTROL, 0);
  aux_reg_write(ARC_V2_TMR1_LIMIT, 0);
  aux_reg_write(ARC_V2_TMR1_COUNT, 0);

  // Timer1 interrupt start.
  interrupt_connect(ARCV2_IRQ_TIMER1, timer1Isr);
  aux_reg_write(ARC_V2_TMR1_LIMIT, 10000);
  aux_reg_write(ARC_V2_TMR1_CONTROL, ARC_V2_TMR_CTRL_NH | ARC_V2_TMR_CTRL_IE);
  aux_reg_write(ARC_V2_TMR1_COUNT, 0);
  interrupt_enable(ARCV2_IRQ_TIMER1);
}

void loop() {
}

void timer1Isr() {
  // Timer1 counter RESET.
  aux_reg_write(ARC_V2_TMR1_COUNT, 0);

  //PWM
  for (int i = 0 ; i < pinCnt; i++) {
    if (PWMPin[i].nextTicks == 0) {
      PWMPin[i].isState = 1 - PWMPin[i].isState;
      digitalWrite(PWMPin[i].nbr, PWMPin[i].isState);
      PWMPin[i].nextTicks = (PWMPin[i].isState ? PWMPin[i].highTicks : PWMPin[i].lowTicks);
    }
  }

  //nextTicks
  unsigned long minTicks = PWMPin[pinCnt - 1].nextTicks;
  for (int i = 0; i < (pinCnt - 1); i++) {
    if (PWMPin[i].nextTicks < minTicks) minTicks = PWMPin[i].nextTicks;
  }
  for (int i = 0; i < pinCnt; i++) {
    PWMPin[i].nextTicks = PWMPin[i].nextTicks - minTicks;
  }

  // Timer1 set
  aux_reg_write(ARC_V2_TMR1_CONTROL, ARC_V2_TMR_CTRL_NH | ARC_V2_TMR_CTRL_IE);
  aux_reg_write(ARC_V2_TMR1_LIMIT, minTicks);
}