Exception(0) with delay() function and interrupts.

[david-boles]

Basic Infos

I'm trying to do stuff in the loop with an external interrupt running. Delaying causes weird crashes...

Hardware

Hardware: ESP-12f
Core Version: 2.3.0

Description

I get a crash from Exception(0) if I use delay(>0) inside the loop with my external interrupt running. Oddly, delay(0) and delayMicroseconds(1000) don't cause a crash.

Settings in IDE

Module: Generic ESP8266 Module
Flash Size: 4MB/1MB
CPU Frequency: 80Mhz
Flash Mode: dio
Flash Frequency: 40Mhz
Upload Using: SERIAL
Reset Method: Hardware (button)

Sketch

#include <ESP8266WiFi.h>
#include <ESP8266mDNS.h>
#include <WiFiUdp.h>
#include <ArduinoOTA.h>

//Pin setup
const int zeroPin = 12;
const int lightPin = 13;

//Timing setup
long triggerDelay = 7300;

//Dimming vars
long prevZeroMicros = 0;

//Pulsing vars
long newVal = 2350;
//boolean rising = true;

void setup() {
  pinMode(zeroPin, INPUT);
  pinMode(lightPin, OUTPUT);
  digitalWrite(lightPin, HIGH);
  Serial.begin(115200);

  attachInterrupt(digitalPinToInterrupt(zeroPin), dimmerCross, RISING);
}

void loop() {


  /*if(rising) newVal++;
  else newVal--;

  if(newVal>=7300) rising = false;
  else if(newVal<=2350) rising = true;
  else triggerDelay = newVal;

  delay(2);*/

  //delay(0);//works fine
  delay(1);//crashes after a little while (~20 sec from upload completion)
  //delayMicroseconds(1000);//works fine
}

void dimmerCross() {
  noInterrupts();
  if(micros()-prevZeroMicros > 6000) {//Check for accidental triggers

    dimm();

    prevZeroMicros = micros();
  }
  interrupts();
}

void dimm() {
  delayMicroseconds(triggerDelay);
  digitalWrite(13, HIGH);
  delayMicroseconds(400);
  digitalWrite(13, LOW);
}

Debug Messages

Console

Exception (0):
epc1=0x40201c90 epc2=0x00000000 epc3=0x00000000 excvaddr=0x00000000 depc=0x00000000

ctx: sys 
sp: 3ffffc30 end: 3fffffb0 offset: 01a0

>>>stack>>>
3ffffdd0:  40106b58 80be5999 fffffff0 3ffee2b8  
3ffffde0:  ffffffff 00000020 40240000 fffffe1a  
3ffffdf0:  00000006 00000006 42da0000 00000022  
3ffffe00:  3fffc200 40106b20 3fffc258 4000050c  
3ffffe10:  400043a3 00000030 00000016 ffffffff  
3ffffe20:  60000200 00000002 7c097c08 80000000  
3ffffe30:  20000000 3fff09d8 80000000 203fc180  
3ffffe40:  00000000 3fffc6fc 3ffee538 3fff09dc  
3ffffe50:  00000174 003fc180 60000600 00000030  
3ffffe60:  7fffffff 3ffe951c 3ffe951c 40201cba  
3ffffe70:  40106bbc 3ffee2b8 00000000 40106ba6  
3ffffe80:  ffffffff 00000020 3fff0004 00000000  
3ffffe90:  00000000 00000000 0000001f 40105139  
3ffffea0:  4000050c 40106b20 3fffc258 4000050c  
3ffffeb0:  40000f68 00000030 00000017 ffffffff  
3ffffec0:  40000f58 00000000 00000020 00000000  
3ffffed0:  feefeffe 3ffee538 3ffee538 fffffffe  
3ffffee0:  ffffffff 3ffede38 3ffee538 3fffdab0  
3ffffef0:  00000000 3fffdad0 3ffee6b0 00000030  
3fffff00:  00000000 400042db 00000064 60000600  
3fffff10:  40004b31 3fff0854 000002f4 003fc000  
3fffff20:  4010569e 3ffede60 3ffecf00 40106d58  
3fffff30:  40206f59 3ffecf00 3ffede60 02aaca2a  
3fffff40:  3fff0854 00001000 402073ee 00000008  
3fffff50:  00000000 00000000 4020749b 3ffecfb4  
3fffff60:  3ffede60 0083e9ab 3ffede60 60000600  
3fffff70:  40218b81 3ffecfb4 3ffede60 02aac843  
3fffff80:  40218bc6 3fffdab0 00000000 3fffdcb0  
3fffff90:  3ffede88 3fffdad0 3ffee6b0 402026cb  
3fffffa0:  40000f49 000180b6 3fffdab0 40000f49  
<<<stack<<<

 ets Jan  8 2013,rst cause:2, boot mode:(1,7)

Decoded stack

0x40106b58: interrupt_handler at /root/.arduino15/packages/esp8266/hardware/esp8266/2.3.0/cores/esp8266/core_esp8266_wiring_digital.c line 119
0x40106b20: interrupt_handler at /root/.arduino15/packages/esp8266/hardware/esp8266/2.3.0/cores/esp8266/core_esp8266_wiring_digital.c line 113
0x40201cba: dimmerCross() at /media/deb/HDD/Documents/Arduino/sketch_jul12b/sketch_jul12b.ino line 52
0x40106bbc: interrupt_handler at /root/.arduino15/packages/esp8266/hardware/esp8266/2.3.0/cores/esp8266/core_esp8266_wiring_digital.c line 135
0x40106ba6: interrupt_handler at /root/.arduino15/packages/esp8266/hardware/esp8266/2.3.0/cores/esp8266/core_esp8266_wiring_digital.c line 131
0x40105139: ets_timer_disarm at ?? line ?
0x40106b20: interrupt_handler at /root/.arduino15/packages/esp8266/hardware/esp8266/2.3.0/cores/esp8266/core_esp8266_wiring_digital.c line 113
0x4010569e: spi_flash_read at ?? line ?
0x40106d58: pvPortZalloc at /root/.arduino15/packages/esp8266/hardware/esp8266/2.3.0/cores/esp8266/heap.c line 33
0x40206f59: pm_set_sleep_time at ?? line ?
0x402073ee: pm_get_sleep_type at ?? line ?
0x4020749b: pm_get_sleep_type at ?? line ?
0x40201018: delay_end at /root/.arduino15/packages/esp8266/hardware/esp8266/2.3.0/cores/esp8266/core_esp8266_wiring.c line 40
0x40218b81: ets_timer_handler_isr at ?? line ?
0x40218bc6: ets_timer_handler_isr at ?? line ?
0x402026cb: loop_task at /root/.arduino15/packages/esp8266/hardware/esp8266/2.3.0/cores/esp8266/core_esp8266_main.cpp line 56

[me-no-dev]

using delay in the interrupt handler is not a good idea, even though it's a short one.
Here is a sketch that I and other users worked on a while back for zero cross dimming:
https://gist.github.com/me-no-dev/2e185a909000f6ac9605
Non-Blocking and no delays

[mkeyno]

@me-no-dev can you suggest schematic for your ZeroCrossTriac.ino sketch

[me-no-dev]

I did not make the device :) maybe @larsenglund can help, but AFAIK it's a pretty standard approach. ZeroCross on GPIO4 and the triac connected to GPIO5

[mkeyno]

@me-no-dev your missing loop function means we could have our specific loop? how it could implemented for dimming purpose

[me-no-dev]

the sketch runs async, so all you need to do in your loop logic is control the period variable to change the dim level

[david-boles]

Thanks, I'll take a look at your code. Still doesn't explain my crashes though...

[igrr]

ISR handler has to be marked with ICACHE_RAM_ATTR.

[david-boles]

Well, I modified your code for 60Hz just to see if it would work off the bat but no luck. I'll see if I can do more testing and merge both a bit...

[david-boles]

Well, that was an easy fix! My code works fine if you just add the ICACHE_RAM_ATTR to my ISR, thanks igrr! Do you know why that's needed? I don't see it mentioned in any ESP8266 or Arduino documentation... I'll probably continue with me-no-dev's way though, as it frees up more processor time.

Modified me-no-dev's dimmer code:

//Dimmer defs
#define TRIAC_PIN       13
#define ZERO_CROSS_PIN  12
#define DEBOUNCE_TIME   6000 //9ms - 10ms is the pulse period

//Dimmer vars
static uint32_t lastPulse = 0;
static uint16_t period    = 7000; //5ms - 50% for each half wave
static bool high = false;

void ICACHE_RAM_ATTR onTimerISR(){
  if(high){//OUTPUT is HIGH
    digitalWrite(TRIAC_PIN, LOW);
    high = false;
  } else {
    digitalWrite(TRIAC_PIN, HIGH);
    high=true;
    timer1_write(400*5);
  }
}

void ICACHE_RAM_ATTR onPinISR(){
  uint32_t now = micros();
  if(now - lastPulse < DEBOUNCE_TIME) return;
  lastPulse = now;
  timer1_write(period * 5);
}

void setup(){
  Serial.begin(115200);
  pinMode(TRIAC_PIN, OUTPUT);
  pinMode(ZERO_CROSS_PIN, INPUT);
  digitalWrite(TRIAC_PIN, LOW);
  timer1_attachInterrupt(onTimerISR);
  timer1_enable(TIM_DIV16, TIM_EDGE, TIM_SINGLE);
  attachInterrupt(digitalPinToInterrupt(ZERO_CROSS_PIN), onPinISR, RISING);
}

long newVal = 2350;
boolean rising = true;

void loop(){
  if(rising) newVal++;
  else newVal--;

  if(newVal>=7300) rising = false;
  else if(newVal<=2350) rising = true;
  else period = newVal;

  delay(1);
}

[igrr]

It is needed because ISR can come at any time, for example when flash cache
is disabled. There's an open ticket in this issue tracker about documenting
ICACHE_RAM_ATTR requirement.

On Sat, Jul 16, 2016, 03:38 david476 notifications@github.com wrote:

Well, that was an easy fix! My code works fine if you just add the
ICACHE_RAM_ATTR to my ISR, thanks igrr! Do you know why that's needed? I
don't see it mentioned in any ESP8266 or Arduino documentation... I'll
probably continue with me-no-dev's way though, as it frees up more
processor time.

Modified me-no-dev's dimmer code:

//Dimmer defs
#define TRIAC_PIN 13
#define ZERO_CROSS_PIN 12
#define DEBOUNCE_TIME 6000 //9ms - 10ms is the pulse period

//Dimmer vars
static uint32_t lastPulse = 0;
static uint16_t period = 7000; //5ms - 50% for each half wave
static bool high = false;

void ICACHE_RAM_ATTR onTimerISR(){
if(high){//OUTPUT is HIGH
digitalWrite(TRIAC_PIN, LOW);
high = false;
} else {
digitalWrite(TRIAC_PIN, HIGH);
high=true;
timer1_write(400*5);
}
}

void ICACHE_RAM_ATTR onPinISR(){
uint32_t now = micros();
if(now - lastPulse < DEBOUNCE_TIME) return;
lastPulse = now;
timer1_write(period * 5);
}

void setup(){
Serial.begin(115200);
pinMode(TRIAC_PIN, OUTPUT);
pinMode(ZERO_CROSS_PIN, INPUT);
digitalWrite(TRIAC_PIN, LOW);
timer1_attachInterrupt(onTimerISR);
timer1_enable(TIM_DIV16, TIM_EDGE, TIM_SINGLE);
attachInterrupt(digitalPinToInterrupt(ZERO_CROSS_PIN), onPinISR, RISING);
}

long newVal = 2350;
boolean rising = true;

void loop(){
if(rising) newVal++;
else newVal--;

if(newVal>=7300) rising = false;
else if(newVal<=2350) rising = true;
else period = newVal;

delay(1);
}

—
You are receiving this because you commented.

Reply to this email directly, view it on GitHub
#2284 (comment),
or mute the thread
https://github.com/notifications/unsubscribe-auth/AEJcenAXSi-zKam9qdYwdKePhdNf1DsJks5qV-G8gaJpZM4JNB-5
.

[mkeyno]

@igrr do you know link or documents which is well described specification and application of ICACHE_xx_ATTR terms ? by the way it is good example of timer's functions in actual sketch, hope find more example

[josep112]

How do I use this code with 2 lamps?
I tried to duplicate the void ICACHE_RAM_ATTR onTimerISR_1 () and void ICACHE_RAM_ATTR onTimerISR_2 () but unsuccessfully