# [SOLVED] Timers and Interrupts not being triggered

• Hi,

I'm making an AC (mains) dimmer using a circuit from this website https://arduinodiy.wordpress.com/2012/10/19/dimmer-arduino/. I basically uses interrupts to detect when the sine wave crosses zero and then triggers a triac. To achieve this I'm using this sketch:

``````/*AC Light Control

Updated by Robert Twomey

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.

Adapted from sketch by Ryan McLaughlin
http://www.arduino.cc/cgi-bin/yabb2/YaBB.pl?num=1230333861/30

*/

#include  <TimerOne.h>          // Avaiable from http://www.arduino.cc/playground/Code/Timer1
volatile int i=0;               // Variable to use as a counter volatile as it is in an interrupt
volatile boolean zero_cross=0;  // Boolean to store a "switch" to tell us if we have crossed zero
int AC_pin = 11;                // Output to Opto Triac
int dim = 0;                    // Dimming level (0-128)  0 = on, 128 = 0ff
int inc=1;                      // counting up or down, 1=up, -1=down

int freqStep = 75;    // This is the delay-per-brightness step in microseconds.
// For 60 Hz it should be 65
// It is calculated based on the frequency of your voltage supply (50Hz or 60Hz)
// and the number of brightness steps you want.
//
// Realize that there are 2 zerocrossing per cycle. This means
// zero crossing happens at 120Hz for a 60Hz supply or 100Hz for a 50Hz supply.

// To calculate freqStep divide the length of one full half-wave of the power
// cycle (in microseconds) by the number of brightness steps.
//
// (120 Hz=8333uS) / 128 brightness steps = 65 uS / brightness step
// (100Hz=10000uS) / 128 steps = 75uS/step

void setup() {                                      // Begin setup
pinMode(AC_pin, OUTPUT);                          // Set the Triac 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 off TRIAC (and AC)
}

// 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+=inc;
if((dim>=128) || (dim<=0))
inc*=-1;
delay(18);
}

``````

The circuit and the sketch works fine until I introduce the mysensors library and a radio. When I do that the interrupt never detects the zero crossing and therefore the triac never triggers. I have not changed anything in my sketch except to include the mysensors library. My modified sketch looks like this:

``````/*AC Light Control

Updated by Robert Twomey

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.

Adapted from sketch by Ryan McLaughlin
http://www.arduino.cc/cgi-bin/yabb2/YaBB.pl?num=1230333861/30

*/
#define MY_DEBUG

#define MY_NODE_ID 300
#define SN "ACDimmer"
#define SV "1.0"
#define AC1_ID 1

#include <MySensors.h>
#include <SPI.h>
#include  <TimerOne.h>          // Avaiable from http://www.arduino.cc/playground/Code/Timer1

volatile int i=0;               // Variable to use as a counter volatile as it is in an interrupt
volatile boolean zero_cross=0;  // Boolean to store a "switch" to tell us if we have crossed zero
int AC_pin = 4;                // Output to Opto Triac
int dim = 0;                    // Dimming level (0-128)  0 = on, 128 = 0ff
int inc=1;                      // counting up or down, 1=up, -1=down
int freqStep = 65;    // This is the delay-per-brightness step in microseconds.
// For 60 Hz it should be 65

MyMessage dimmerMsg(AC1_ID, V_DIMMER);

void setup() {                                      // Begin setup
pinMode(AC_pin, OUTPUT);                          // Set the Triac pin as output
attachInterrupt(1, 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);
}

void presentation() {
// Register the LED Dimmable Light with the gateway
present( AC1_ID, S_DIMMER );

sendSketchInfo(SN, SV);
}

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 off TRIAC (and AC)
}

// 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+=inc;
if((dim>=128) || (dim<=0))
inc*=-1;
delay(18);
}
``````

My node registers with my gateway and all seems fine. Is the mysensors library using the same timer?

Any help would be appreciated.

Thank you,

Mike

• @Mike-Cayouette you changed the interrupt number to attach to from 0 to 1, which is probably causing the issue.
Hardcoding the number is bad coding practice; see https://www.arduino.cc/en/Reference/AttachInterrupt
Use the digitalPinToInterrupt() function instead to convert pin number to interrupt number.

• @Yveaux Sorry for the confusion. In my testing I did in fact change the original sketch to use interrupt 1 as I have in my modified sketch and it worked. I did this knowing the radio was going to be connected to 0. I understand your comment about hard coding the interrupt and agree it is not best practice, however, that does not take away from the fact that the sketch did not work when I added the mysensors library in my changes. I believe, even with it hard coded, it should have worked or am I missing something?

Thank you,

Mike

• Just to be clear, below is the exact sketch that I used, i added the digitalPinToInterrupt() to the sketch.

``````/*AC Light Control

Updated by Robert Twomey

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.

Adapted from sketch by Ryan McLaughlin
http://www.arduino.cc/cgi-bin/yabb2/YaBB.pl?num=1230333861/30

*/

#include  <TimerOne.h>          // Avaiable from http://www.arduino.cc/playground/Code/Timer1
volatile int i=0;               // Variable to use as a counter volatile as it is in an interrupt
volatile boolean zero_cross=0;  // Boolean to store a "switch" to tell us if we have crossed zero
int AC_pin = 4;                // Output to Opto Triac
int interruptPin = 3;
int dim = 0;                    // Dimming level (0-128)  0 = on, 128 = 0ff
int inc=1;                      // counting up or down, 1=up, -1=down

int freqStep = 65;    // This is the delay-per-brightness step in microseconds.
// For 60 Hz it should be 65
// It is calculated based on the frequency of your voltage supply (50Hz or 60Hz)
// and the number of brightness steps you want.
//
// Realize that there are 2 zerocrossing per cycle. This means
// zero crossing happens at 120Hz for a 60Hz supply or 100Hz for a 50Hz supply.

// To calculate freqStep divide the length of one full half-wave of the power
// cycle (in microseconds) by the number of brightness steps.
//
// (120 Hz=8333uS) / 128 brightness steps = 65 uS / brightness step
// (100Hz=10000uS) / 128 steps = 75uS/step

void setup() {                                      // Begin setup
pinMode(AC_pin, OUTPUT);                          // Set the Triac pin as output
attachInterrupt(digitalPinToInterrupt(interruptPin), 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 off TRIAC (and AC)
}

// 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+=inc;
if((dim>=128) || (dim<=0))
inc*=-1;
delay(18);
}

``````

The above sketch works as intended. When I add the mysensors library to the sketch, as I did below, the triac never gets triggered.

``````/*AC Light Control

Updated by Robert Twomey

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.

Adapted from sketch by Ryan McLaughlin
http://www.arduino.cc/cgi-bin/yabb2/YaBB.pl?num=1230333861/30

*/
#define MY_DEBUG

#define MY_NODE_ID 300
#define SN "ACDimmer"
#define SV "1.0"
#define AC1_ID 1

#include <MySensors.h>
#include <SPI.h>
#include  <TimerOne.h>          // Avaiable from http://www.arduino.cc/playground/Code/Timer1

volatile int i=0;               // Variable to use as a counter volatile as it is in an interrupt
volatile boolean zero_cross=0;  // Boolean to store a "switch" to tell us if we have crossed zero
int AC_pin = 4;                 // Output to Opto Triac
int interruptPin = 3;
int dim = 0;                    // Dimming level (0-128)  0 = on, 128 = 0ff
int inc=1;                      // counting up or down, 1=up, -1=down
int freqStep = 65;    // This is the delay-per-brightness step in microseconds.
// For 60 Hz it should be 65

MyMessage dimmerMsg(AC1_ID, V_DIMMER);

void setup() {                                        // Begin setup
pinMode(AC_pin, OUTPUT);                            // Set the Triac pin as output
attachInterrupt(digitalPinToInterrupt(interruptPin), 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);
}

void presentation() {
// Register the LED Dimmable Light with the gateway
present( AC1_ID, S_DIMMER );

sendSketchInfo(SN, SV);
}

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 off TRIAC (and AC)
}

// 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+=inc;
if((dim>=128) || (dim<=0))
inc*=-1;
delay(18);
}

``````

What would be preventing the interrupt from triggering?

Thank you,

Mike

• @Mike-Cayouette then I guess dim_check never gets called. Can you check if the timer works as expected?

• @Yveaux How can I get Serial.println to work? I'm using the new 2.0 library and I have a few Serail.println() command in various places, including in void setup(), but I am not getting any output on the serial monitor except for all the debug data.

Sketch with serial output:

``````/*AC Light Control

Updated by Robert Twomey

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.

Adapted from sketch by Ryan McLaughlin
http://www.arduino.cc/cgi-bin/yabb2/YaBB.pl?num=1230333861/30

*/
#define MY_DEBUG

#define MY_NODE_ID 300
#define SN "ACDimmer"
#define SV "1.0"
#define AC1_ID 1

#include <MySensors.h>
#include <SPI.h>
#include <TimerOne.h>          // Avaiable from http://www.arduino.cc/playground/Code/Timer1

volatile int i=0;               // Variable to use as a counter volatile as it is in an interrupt
volatile boolean zero_cross=0;  // Boolean to store a "switch" to tell us if we have crossed zero
int AC_pin = 4;                 // Output to Opto Triac
int interruptPin = 3;
int dim = 0;                    // Dimming level (0-128)  0 = on, 128 = 0ff
int inc=1;                      // counting up or down, 1=up, -1=down
int freqStep = 65;    // This is the delay-per-brightness step in microseconds.
// For 60 Hz it should be 65

MyMessage dimmerMsg(AC1_ID, V_DIMMER);

void setup() {                                        // Begin setup
Serial.println("Dim Sketch started");

pinMode(AC_pin, OUTPUT);                            // Set the Triac pin as output
attachInterrupt(digitalPinToInterrupt(interruptPin), 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);

}

void presentation() {
// Register the LED Dimmable Light with the gateway
present( AC1_ID, S_DIMMER );

sendSketchInfo(SN, SV);
}

void zero_cross_detect() {
Serial.println("Zero Cross");

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 off TRIAC (and AC)
}

// Turn on the TRIAC at the appropriate time
void dim_check() {
Serial.println("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() {
Serial.print("Dim value: ");
Serial.println(String(dim));

dim+=inc;
if((dim>=128) || (dim<=0))
inc*=-1;
delay(18);
}

``````

• @Mike-Cayouette if you don't have MY_DEBUG defined you should call Serial.begin() with the Baudelaire yourself.

• @Yveaux There is something wrong with the Serial print command. I have the most basic of sketches below but I see none on the Serial.println() output, but I get all the debug output.

``````#define MY_DEBUG

#define SN "ACDimmer"
#define SV "1.0"

#include <SPI.h>
#include <MySensors.h>

int AC1_ID = 1;

MyMessage dimmerMsg(AC1_ID, V_DIMMER);

void setup() {                                        // Begin setup
Serial.println("Dim Sketch started");
}

void presentation() {
// Register the LED Dimmable Light with the gateway
present( AC1_ID, S_DIMMER );

sendSketchInfo(SN, SV);
}

void loop() {
Serial.println("Loop");
}

``````

what am I doing wrong?

Mike

• @Mike-Cayouette Maybe this helps

``````void setup() {                                        // Begin setup
Serial.begin( 115200 );
Serial.println("Dim Sketch started");
}
``````

• @TheoL I tried that also but I thought that was not needed if MY_DEBUG was defined. In any case, event with Serial.begin( 115200 ) it still does not work.

I did notice the following 2 errors in the debug output, one after the other.

``````TSP:CHKUPL:FAIL (hops=255)
!TSM:UPL:FAIL
``````

but I see my sensor registered on my MQTT server.

Thank you,

Mike

• @Mike-Cayouette I think you won't be getting any serial output from the println's because the node cannot get a handshake with the gateway. But I'm still not familiar with the new debug output.

• @Mike-Cayouette try putting the code suggested by @theol in the before() method instead of in setup()

• @Yveaux There is still something odd happening. This is now my basic sketch

``````//#define MY_DEBUG

//#define MY_NODE_ID 300
#define SN "ACDimmer"
#define SV "1.0"

#include <SPI.h>
#include <MySensors.h>

unsigned long previousMillis = 0;
unsigned long currentMillis = 0;
int AC1_ID = 1;
int SET_DELAY = 300;

MyMessage dimmerMsg(AC1_ID, V_DIMMER);

void before() {
Serial.begin( 115200 );
Serial.println("Dim Sketch started");

}

void setup() {                                        // Begin setup
}

void presentation() {
// Register the LED Dimmable Light with the gateway
present( AC1_ID, S_DIMMER );

sendSketchInfo(SN, SV);
}

void loop()
{
Serial.println("Loop");
if (currentMillis - previousMillis > SET_DELAY) {
send( dimmerMsg.set("Message From Dimmer") );
previousMillis = millis();
}
currentMillis = millis();

}

``````

I get the output that is in the before() method, but what I have in the loop is not output at all. Its as if loop is not running at all.

Mike

• @Mike-Cayouette that's because the mysensors stack doesn't start (e.g radio fails to initialize, or parent can not be found)
That is probably also causing setup() not to be called and your timer not being registered!

• @Yveaux I find it hard to believe that the radio is not initialized. My MQTT server receives the following when I have the node running:

``````mymqtt-out/44/255/3/0/24
``````

``````void receive(const MyMessage &message) {

Serial.print("Message: ");
Serial.println(message.type);
Serial.print("Message Data: ");
Serial.println(message.data);

}
``````

when I send a payload of 50 to mymqtt-in/44/1/1/0/3, the serial output shows the following:

``````Dim Sketch started
Message: 3
Message Data: 50
``````

I would think if the radio is not initialized this would not be possible.

My debug output is below:

``````Dim Sketch started
Starting sensor (RNNNA-, 2.0.0)
TSM:INIT
TSP:ASSIGNID:OK (ID=44)
TSM:FPAR
TSP:MSG:SEND 44-44-255-255 s=255,c=3,t=7,pt=0,l=0,sg=0,ft=0,st=bc:
TSP:MSG:FPAR RES (ID=0, dist=0)
TSP:MSG:PAR OK (ID=0, dist=1)
TSM:FPAR:OK
TSM:ID
TSM:CHKID:OK (ID=44)
TSM:UPL
TSP:PING:SEND (dest=0)
TSP:MSG:SEND 44-44-0-0 s=255,c=3,t=24,pt=1,l=1,sg=0,ft=0,st=ok:1
TSP:CHKUPL:FAIL (hops=255)
!TSM:UPL:FAIL
TSM:FPAR
TSP:MSG:SEND 44-44-255-255 s=255,c=3,t=7,pt=0,l=0,sg=0,ft=0,st=bc:
TSP:MSG:FPAR RES (ID=0, dist=0)
TSP:MSG:PAR OK (ID=0, dist=1)
TSM:FPAR:OK
TSM:ID
``````

I remember in the past when the radio would not initialize it said radio init failed or something like that.

Thank you,

Mike

• @Yveaux I solved the problem.

The issue was not my sketch, but rather my ESP8266 MQTT Gateway. I was using an older development version. After upgrading to version 2.0 everything started working. Thankfully my older nodes, using the older development version, are still working, I will upgrade them over time.

This is my final sketch:

``````#define MY_DEBUG

#define MY_NODE_ID 300

#define SN "ACDimmer"
#define SV "1.0"
#define AC1_ID 1
#define FADE_DELAY 18      // Delay in ms for each percentage fade up/down (10ms = 1s full-range dim)

#include <TimerOne.h>
#include <SPI.h>
#include <MySensors.h>

MyMessage dimmerMsg(AC1_ID, V_DIMMER);

volatile int i=0;               // Variable to use as a counter volatile as it is in an interrupt
volatile boolean zero_cross=0;  // Boolean to store a "switch" to tell us if we have crossed zero
int AC_pin = 4;                // Output to Opto Triac
int intPin = 3;
int dim = 0;                    // Dimming level (0-128)  0 = on, 128 = 0ff
int inc=1;                      // counting up or down, 1=up, -1=down
int freqStep = 65;    // This is the delay-per-brightness step in microseconds.
unsigned long previousMillis = 0;        // will store last time LED was updated
unsigned long currentMillis = 0;
int currentLevel =  0;
int requestedLevel = 0;

void before() {
#ifdef MY_DEBUG
Serial.println("Dimmer Node Starting");
#endif

pinMode(AC_pin, OUTPUT);                          // Set the Triac pin as output
attachInterrupt(digitalPinToInterrupt(intPin), 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);
}

void setup() {                                      // Begin setup
}

void presentation() {
present( AC1_ID, S_DIMMER );

sendSketchInfo(SN, SV);
}

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 off TRIAC (and AC)
}

// Turn on the TRIAC at the appropriate time
void dim_check() {
if(zero_cross == true) {
if(i>=currentLevel) {
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() {

}

#ifdef MY_DEBUG
Serial.print("Message: ");
Serial.println(message.type);
Serial.print("Message Data: ");
Serial.println(message.data);
#endif

if (message.type == 3) {
int requestedLevel = map(atoi( message.data ), 0, 100, 128, 0); //128 = off | 0 = ON

while (currentLevel != requestedLevel) {

if(currentLevel<=requestedLevel) inc=1;
if(currentLevel>=requestedLevel) inc=-1;

currentLevel+=inc;

#ifdef MY_DEBUG
Serial.print("Current Level:");
Serial.println(String(currentLevel));
#endif

//delay
currentMillis = previousMillis = millis();
while (currentMillis - previousMillis < FADE_DELAY) {
currentMillis = millis();
}

}

}
}
``````

There is still one error though. When I try to set my own node id using #define MY_NODE_ID 300, I get the following error:

``````In file included from /home/sketchbook/libraries/MySensors/MySensors.h:253:0,
from /home/sketchbook/ACDimmer_Test/ACDimmer_Test.ino:11:
/home/sketchbook/libraries/MySensors/core/MyTransport.cpp: In function 'void stInitTransition()':
/home/sketchbook/libraries/MySensors/core/MyTransport.cpp:74:16: warning: large integer implicitly truncated to unsigned type [-Woverflow]
_nc.nodeId = MY_NODE_ID;
^
In file included from /home/sketchbook/libraries/MySensors/core/MyHwATMega328.cpp:22:0,
from /home/sketchbook/libraries/MySensors/MySensors.h:69,
from /home/sketchbook/ACDimmer_Test/ACDimmer_Test.ino:11:
/home/sketchbook/libraries/MySensors/core/MyHwATMega328.h:69:88: warning: large integer implicitly truncated to unsigned type [-Woverflow]
#define hwWriteConfig(__pos, __value) (eeprom_update_byte((uint8_t*)(__pos), (__value)))
^
/home/sketchbook/libraries/MySensors/core/MyTransport.cpp:76:5: note: in expansion of macro 'hwWriteConfig'
``````

I was able to set my own node id's in the older development version but it does not seem to work now.

Thank you for all your help.

Mike

• @Mike-Cayouette node id needs to be in the range of 1..254.

• @Mike-Cayouette well, suggesting the radio fails was just one of the many possible failures as I indicated.
Great to hear you finally nailed it!

• @mfalkvidd Node id's work now.

Thank you everyone for your help.

Mike