Dimmer de 2 canais - Arquivo 010

Referência:
http://www.instructables.com/id/3-channel-Dimmerfader-for-Arduino-or-other-microco/step2/3-channel-Dimmerfader-for-Arduino-or-other-microco/
http://br-arduino.org/2016/04/arduino-interrupcoes-timer1.html

Lista de Materiais:
IDE Arduino 1.0.6
1x  Board Arduino MEGA 2560
1x  Cabo USB-A male to USB-B male 
2x  Lâmpada incandescente 40w 127Vac
2x  Bocal para lâmpada
1x  Shield Mega Relay & Dimmer V.2.1 

Montagem:

Firmware 01:
int AC_LOAD = 5;             // Output to Opto Triac pin
int dimming;                      // Dimming level (0-128)  0 = ON, 128 = OFF
//*******************************************************************************
void setup(){
  pinMode(AC_LOAD, OUTPUT);
  attachInterrupt(0, zero_crosss_int, RISING);
}
//*******************************************************************************
void zero_crosss_int() {
  int dimtime = (65*dimming);      
  delayMicroseconds(dimtime);                      // Off cycle
  digitalWrite(AC_LOAD, HIGH);                 // triac firing
  delayMicroseconds(8.33);                            // triac On propogation delay
  digitalWrite(AC_LOAD, LOW);                 // triac Off
}
//*******************************************************************************

void loop(){

  dimming = 100;  
}

Firmware 02:
#include <TimerOne.h>  
         
#define PINS 2
//*******************************************************************************
volatile int pinCount[PINS];    
volatile boolean zero_cross=0;  
int AC_pins[] = {4,5};        
int AC_dim[PINS];           
int freqStep = 65;   
//*******************************************************************************
void setup() {
  for(int a=0; a < PINS; a++) { 
   pinMode(AC_pins[a],OUTPUT);
   pinCount[a] = 0;            
   AC_dim[a] = 0;              
  }
  attachInterrupt(0, zero_cross_detect, FALLING); 
  Serial.begin(9600);
  Timer1.initialize(freqStep);                   
  Timer1.attachInterrupt(dim_check, freqStep);                                               
}
//*******************************************************************************
void zero_cross_detect() {                                 
   zero_cross = 1;             
}                                
//*******************************************************************************
void dim_check() {                
 if(zero_cross == 1) {            
   for(int a=0; a < PINS; a++) {
     if(pinCount[a] >= AC_dim[a]) {    
       digitalWrite(AC_pins[a], HIGH);   
       delayMicroseconds(5);              
       digitalWrite(AC_pins[a], LOW);    
       pinCount[a] = 0;            
       zero_cross = 0;                        
     } else {
       pinCount[a]++;                    
     }    
   }
 }
}
//*******************************************************************************
void loop() {
 for(int i=0; i<127; i ++) {
   for(int a=0; a < PINS; a++) {
      int ii = i+42;          
      if(ii > 127) ii -= 127;
      AC_dim[a] = ii;
    }
    delay(50);
  }
}

Download: TimerOne.h