AC Light Control
Updated by Robert Twomey <rtwomey@u.washington.edu>
Changed zero-crossing detection to look for RISING edge rather
than falling. (originally it was only chopping the negative half
of the AC wave form).
Also changed the dim_check() to turn on the Triac, leaving it on
until the zero_cross_detect() turn's it off.
Ryan McLaughlin <ryanjmclaughlin@gmail.com>
The hardware consists of an Triac to act as an A/C switch and
an opto-isolator to give us a zero-crossing reference.
The software uses two interrupts to control dimming of the light.
The first is a hardware interrupt to detect the zero-cross of
the AC sine wave, the second is software based and always running
at 1/128 of the AC wave speed. After the zero-cross is detected
the function check to make sure the proper dimming level has been
reached and the light is turned on mid-wave, only providing
partial current and therefore dimming our AC load.
Thanks to http://www.andrewkilpatrick.org/blog/?page_id=445
and http://www.hoelscher-hi.de/hendrik/english/dimmer.htm
*/
#include <TimerOne.h> // Avaiable from http://www.arduino.cc/playground/Code/Timer1
volatile int i=0; // Variable to use as a counter
volatile boolean zero_cross=0; // Boolean to store a "switch" to tell us if we have crossed zero
int AC_pin = 3; // Output to Opto Triac
int POT_pin = A3; // Pot for testing the dimming
int LED = 11; // LED for testing
int dim = 0; // Dimming level (0-128) 0 = on, 128 = 0ff
int freqStep = 75; // This is the delay-per-brightness step in microseconds.
// It is calculated based on the frequency of your voltage supply (50Hz or 60Hz)
// and the number of brightness steps you want.
//
// The only tricky part is that the chopper circuit chops the AC wave twice per
// cycle, once on the positive half and once at the negative half. This meeans
// the chopping happens at 120Hz for a 60Hz supply or 100Hz for a 50Hz supply.
// To calculate freqStep you divide the length of one full half-wave of the power
// cycle (in microseconds) by the number of brightness steps.
//
// (1000000 uS / 120 Hz) / 128 brightness steps = 65 uS / brightness step
//
// 1000000 us / 120 Hz = 8333 uS, length of one half-wave.
void setup() { // Begin setup
pinMode(AC_pin, OUTPUT); // Set the Triac pin as output
pinMode(LED, OUTPUT); // Set the LED pin as output
attachInterrupt(0, zero_cross_detect, RISING); // Attach an Interupt to Pin 2 (interupt 0) for Zero Cross Detection
Timer1.initialize(freqStep); // Initialize TimerOne library for the freq we need
Timer1.attachInterrupt(dim_check, freqStep);
// Use the TimerOne Library to attach an interrupt
// to the function we use to check to see if it is
// the right time to fire the triac. This function
// will now run every freqStep in microseconds.
}
void zero_cross_detect() {
zero_cross = true; // set the boolean to true to tell our dimming function that a zero cross has occured
i=0;
digitalWrite(AC_pin, LOW);
}
// Turn on the TRIAC at the appropriate time
void dim_check() {
if(zero_cross == true) {
if(i>=dim) {
digitalWrite(AC_pin, HIGH); // turn on light
i=0; // reset time step counter
zero_cross=false; // reset zero cross detection
}
else {
i++; // increment time step counter
}
}
}
void loop() {
dim = analogRead(POT_pin) / 8; // read dimmer value from potentiometer
analogWrite(LED, dim); // write dimmer value to the LED, for debugging
}
Cateva stari ale intensitatii becului:
Un filmulet cu functionarea acestui variator de tensiune pentru bec comandat de un potentiometru se numeste ac light dimmer with Arduino (XIII):
Al doilea sketch pe care l-am folosit folosesc 2 LED-uri din cele 3 ale LED-lui multicolor pentru a prezenta starea becului, doar LED-ul albastru aprins indica bec stins, iar doar LED-ul rosu aprins indica bec aprins la intensitate maxima:
/*
AC Light Control
Updated by Robert Twomey <rtwomey@u.washington.edu>
Ryan McLaughlin <ryanjmclaughlin@gmail.com>
Thanks to http://www.andrewkilpatrick.org/blog/?page_id=445
and http://www.hoelscher-hi.de/hendrik/english/dimmer.htm
modified sketch by niq_ro from http://www.tehnic.go.ro &
http://www.nicuflorica.blogspot.com
version 1m2 - 15.04.2013
*/
#include <TimerOne.h> // Avaiable from http://www.arduino.cc/playground/Code/Timer1
volatile int i=0; // Variable to use as a counter
volatile boolean zero_cross=0; // Boolean to store a "switch" to tell us if we have crossed zero
int AC_pin = 3; // Output to Opto Triac
int POT_pin = A3; // Pot for testing the dimming
int LED = 10; // LED for testing
int LED2 =11; // second LED
int dim = 0; // Dimming level (0-128) 0 = on, 128 = 0ff
int freqStep = 75; // This is the delay-per-brightness step in microseconds (for 50Hz)
void setup() { // Begin setup
pinMode(AC_pin, OUTPUT); // Set the Triac pin as output
pinMode(LED, OUTPUT); // Set the LED pin as output
pinMode(LED2, OUTPUT); // Set the LED2 pin as output
attachInterrupt(0, zero_cross_detect, RISING); // Attach an Interupt to Pin 2 (interupt 0) for Zero Cross Detection
Timer1.initialize(freqStep); // Initialize TimerOne library for the freq we need
Timer1.attachInterrupt(dim_check, freqStep);
// Use the TimerOne Library to attach an interrupt
// to the function we use to check to see if it is
// the right time to fire the triac. This function
// will now run every freqStep in microseconds.
}
void zero_cross_detect() {
zero_cross = true; // set the boolean to true to tell our dimming function that a zero cross has occured
i=0;
digitalWrite(AC_pin, LOW);
}
// Turn on the TRIAC at the appropriate time
void dim_check() {
if(zero_cross == true) {
if(i>=dim) {
digitalWrite(AC_pin, HIGH); // turn on light
i=0; // reset time step counter
zero_cross=false; // reset zero cross detection
}
else {
i++; // increment time step counter
}
}
}
void loop() {
dim = analogRead(POT_pin) / 8; // read dimmer value from potentiometer
analogWrite(LED, dim); // write dimmer value to the LED, for debugging
analogWrite(LED2, 255-2*dim); // write dimmer value to the second LED, for debugging
}
Cateva poze:
/*
AC Light Control
Updated by Robert Twomey <rtwomey@u.washington.edu>
Thanks to http://www.andrewkilpatrick.org/blog/?page_id=445
and http://www.hoelscher-hi.de/hendrik/english/dimmer.htm
adapted sketch by niq_ro from
http://www.tehnic.go.ro
http://www.niqro.3x.ro
http://nicuflorica.blogspot.com
*/
#include <TimerOne.h> // Avaiable from http://www.arduino.cc/playground/Code/Timer1
volatile int i=0; // Variable to use as a counter
volatile boolean zero_cross=0; // Boolean to store a "switch" to tell us if we have crossed zero
int AC_pin = 3; // Output to Opto Triac
int buton1 = 4; // first button at pin 4
int buton2 = 5; // second button at pin 5
int buton3 = 6; // second button at pin 6
int buton4 = 7; // second button at pin 7
int redLED = 11; // red LED at pin 11
int greenLED = 9; // green LED at pin 9
int blueLED = 10; // blue LED at pin 10
int dim2 = 0; // led control
int dim = 128; // Dimming level (0-128) 0 = on, 128 = 0ff
int pas = 8; // step for count;
// version: 4m7 (15.04.2013 - Craiova, Romania) - 16 steps, 4 button & LED blue to red (off to MAX)
int freqStep = 75; // This is the delay-per-brightness step in microseconds.
void setup() { // Begin setup
Serial.begin(9600);
pinMode(buton1, INPUT); // set buton1 pin as input
pinMode(AC_pin, OUTPUT); // Set the Triac pin as output
pinMode(redLED, OUTPUT); // Set the LED pin as output
pinMode(greenLED, OUTPUT); // Set the LED pin as output
pinMode(blueLED, OUTPUT); // Set the LED pin as output
attachInterrupt(0, zero_cross_detect, RISING); // Attach an Interupt to Pin 2 (interupt 0) for Zero Cross Detection
Timer1.initialize(freqStep); // Initialize TimerOne library for the freq we need
Timer1.attachInterrupt(dim_check, freqStep);
// Use the TimerOne Library to attach an interrupt
}
void zero_cross_detect() {
zero_cross = true; // set the boolean to true to tell our dimming function that a zero cross has occured
i=0;
digitalWrite(AC_pin, LOW);
}
// Turn on the TRIAC at the appropriate time
void dim_check() {
if(zero_cross == true) {
if(i>=dim) {
digitalWrite(AC_pin, HIGH); // turn on light
i=0; // reset time step counter
zero_cross=false; // reset zero cross detection
}
else {
i++; // increment time step counter
}
}
}
void loop() {
if (digitalRead(buton3) == LOW)
{
dim = 0;
}
if (digitalRead(buton4) == LOW)
{
dim = 127;
}
if (digitalRead(buton1) == LOW)
{
if (dim<127)
{
dim = dim + pas;
if (dim>127)
{
dim=127;
}
}
else
{
analogWrite(greenLED, 255); // LED is ON for indicate an error
delay (100);
analogWrite(greenLED, 0); // LED is now OFF
}
}
if (digitalRead(buton2) == LOW)
{
if (dim>5)
{
dim = dim - pas;
if (dim<0)
{
dim=1;
}
}
else
{
analogWrite(greenLED, 255); // LED is ON for indicate an error
delay (100);
analogWrite(greenLED, 0); // LED is now OFF
}
}
while (digitalRead(buton1) == LOW) { }
delay(10); // waiting little bit...
while (digitalRead(buton2) == LOW) { }
delay(10); // waiting little bit...
analogWrite(blueLED, 2*dim); // write dimmer value to the LED, for debugging
dim2 = 255-2*dim;
if (dim2<0)
{
dim2 = 0;
}
analogWrite(redLED, dim2); // write dimmer value to the LED, for debugging
Serial.print("dim=");
Serial.print(dim);
Serial.print(" dim2=");
Serial.print(dim2);
Serial.print(" dim1=");
Serial.print(2*dim);
Serial.print('\n');
delay (100);
}
