timerAttachInterrupt(): EDGE timer interrupt is not supported

codehampster · October 23, 2022, 2:05am

Developing on ESP32 Firebeetle and trying to add watchdog with timer on my task execution scheduler. Having the following code

main.h
#include “esp_system.h”
#include “esp_int_wdt.h”
#include “esp_task_wdt.h”
…
hw_timer_t * timer = NULL;
portMUX_TYPE timerMux = portMUX_INITIALIZER_UNLOCKED;
int flag[] = {0, 0, 0, 0,0,0,0,0,0,0};

main.cpp

void IRAM_ATTR onTimer() {
portENTER_CRITICAL_ISR(&timerMux);
// Check all flags if True then kick the dog
if (flag[0] == 1 && flag[1] == 1 && flag[2] == 1 && flag[3] == 1 && flag[4] == 1 && flag[5] == 1 && flag[6] == 1 && flag[7] == 1 && flag[8] == 1 && flag[9] == 1) {
// Reset all flags
flag[0] = 0;
flag[1] = 0;
flag[2] = 0;
flag[3] = 0;
flag[4] = 0;
flag[5] = 0;
flag[6] = 0;
flag[7] = 0;
flag[8] = 0;
flag[9] = 0;
// Kick the dog
timerWrite(timer, 0);
}
else {
ESP.restart();
}
portEXIT_CRITICAL_ISR(&timerMux);
}

void setup() {
Wire.begin();
Serial.begin(SERIAL_LOGGER_BAUD_RATE);
set_logging_function(logging_function)
Serial.println(“Starting up…”);
vTaskDelay( 1000 / portTICK_PERIOD_MS );

timer = timerBegin(0, 80, true);
timerAttachInterrupt(timer, &onTimer, true);
timerAlarmWrite(timer, WDT_TIMEOUT * 1000000, true);
timerAlarmEnable(timer);

esp_task_wdt_init(WDT_TIMEOUT, true); // Initialize ESP32 Task WDT
esp_task_wdt_add(NULL);               // Subscribe to the Task WDT

…

Code compiles correctly but when i run it on the device the following part comes on restart:

ets Jul 29 2019 12:21:46

rst:0xc (SW_CPU_RESET),boot:0x17 (SPI_FAST_FLASH_BOOT)
configsip: 0, SPIWP:0xee
clk_drv:0x00,q_drv:0x00,d_drv:0x00,cs0_drv:0x00,hd_drv:0x00,wp_drv:0x00
mode:DIO, clock div:2
load:0x3fff0030,len:1184
load:0x40078000,len:13132
load:0x40080400,len:3036
entry 0x400805e4
[��mum��2-hal-cpu.c:214] setCpuFrequencyMhz(): PLL: 480 / 2 = 240 Mhz, APB: 80000000 Hz
Starting up…
[ 1027][W][esp32-hal-timer.c:226] timerAttachInterrupt(): EDGE timer interrupt is not supported! Setting to LEVEL…

Been trying to look through tutorials but to no avail. Running the latest frameworks.

Many thanks

normandunbar · October 23, 2022, 9:30am

nything useful here? Hardware timer issue with ESP32

I notice a couple of issues on the Arduino/espressif github, but they have been closed. The advice there is to use an Arduino library called “Ticker”. I don’t know if that will help, sorry.

Cheers,
Norm.

maxgerhardt · October 23, 2022, 11:54am

github.com/espressif/arduino-esp32

Timer functions do not work at all in PlatformIO

opened 11:37AM - 28 Jun 21 UTC

closed 12:44PM - 28 Jun 21 UTC

maxgerhardt

### Hardware: Board: ESP32 Dev Module Core Installation version: 1.0.6… as well as 2.0.0-alpha1 and current master 21947ebe76cf6380fe06aa885390b86cc477709a IDE name: Platform.io Flash Frequency: 40Mhz PSRAM enabled: no Upload Speed: 921600 Computer OS: Windows 10 ### Description: I am attempting to replicate the tutorial [Hardware Interrrupts](https://www.youtube.com/watch?v=qsflCf6ahXU&list=PLEBQazB0HUyQ4hAPU1cJED6t3DU0h34bz&index=10) here, specifically the code [here](https://github.com/ShawnHymel/introduction-to-rtos/blob/main/09-hardware-interrupts/esp32-freertos-09-demo-timer-interrupt/esp32-freertos-09-demo-timer-interrupt.ino). The sketch uses functions from `esp32-hal-timer.c` to setup timer 0 with an alarm that will trigger the execution of an ISR in which a pin is toggled at a rate of 1Hz. When uploading this sketch in PlatformIO, using all default settings (meaning also core version 1.0.6), this does not work. There is no blinking going on the defined LED pin at all. The following sketch was used, which additionally prints some debug information on the `Serial`. A LED is connected to IO2. ```cpp #include <Arduino.h> // Settings static const uint16_t timer_divider = 80; static const uint64_t timer_max_count = 1000000; // Pins (change this if your Arduino board does not have LED_BUILTIN defined) static const int led_pin = 2; // Globals static hw_timer_t *timer = NULL; //***************************************************************************** // Interrupt Service Routines (ISRs) // This function executes when timer reaches max (and resets) void IRAM_ATTR onTimer() { // Toggle LED int pin_state = digitalRead(led_pin); digitalWrite(led_pin, !pin_state); } //***************************************************************************** // Main (runs as its own task with priority 1 on core 1) void setup() { Serial.begin(115200); Serial.println("Firmware start"); // Configure LED pin pinMode(led_pin, OUTPUT); // Create and start timer (num, divider, countUp) timer = timerBegin(0, timer_divider, true); // Provide ISR to timer (timer, function, edge) timerAttachInterrupt(timer, &onTimer, true); // At what count should ISR trigger (timer, count, autoreload) timerAlarmWrite(timer, timer_max_count, true); // Allow ISR to trigger timerAlarmEnable(timer); } void loop() { Serial.println("Timer seconds: " + String(timerReadSeconds(timer))); Serial.println("Timer alarm seconds: " + String(timerAlarmReadSeconds(timer))); Serial.println("Timer is alarm enabled: " + String(timerAlarmEnabled(timer))); Serial.println("Timer is started: " + String(timerStarted(timer))); delay(250); } ``` `platformio.ini` ```ini [env:esp32] platform = espressif32 board = esp32dev framework = arduino monitor_speed = 115200 upload_speed = 921600 ``` The serial output clearly shows the problem: The alarm in the timer is not enabled. ``` Firmware start Timer seconds: 0.00 Timer alarm seconds: 1.00 Timer is alarm enabled: 0 Timer is started: 1 Timer seconds: 0.00 Timer alarm seconds: 1.00 Timer is alarm enabled: 0 Timer is started: 1 Timer seconds: 0.25 ``` Time keeps advancing as expected for the timer though. I was able to fix this issue by going into the `C:\Users\<user>\.platformio\packages\framework-arduinoespressif32\cores\esp32\esp32-hal-timer-c` file and adding `volatile` declaration to the timer registers struct. https://github.com/espressif/arduino-esp32/blob/21947ebe76cf6380fe06aa885390b86cc477709a/cores/esp32/esp32-hal-timer.c#L50-L54 to ```cpp typedef volatile struct { //... ``` Adding this single keyword immediately got the LED blinking. So okay I think, the Arduino-ESP32 has a bug regarding compiler optimizations where a write to the alarm-enable register is not executed in order (or, at all) due to the developers forgetting that the registers need to be marked `volatile`. That fixes it for the 1.0.6 core. Note that the same fixing effect can be achieved by not declaring the struct `volatile` but instead placing a call to function between `timerAlarmWrite()` and `timerAlarmEnable()` in `setup()`, e.g. a simple `delayMicroseconds(0);`. This strongly hints at me to the compiler optimizing (away) or reordering something in the sequence of writes to the timer registers. **However**, I then also cross-checked with the latest master version of the core and compiler. ```ini [env:esp32] platform = espressif32 board = esp32dev framework = arduino monitor_speed = 115200 upload_speed = 921600 platform_packages = toolchain-xtensa32 @ ~2.80400.0 framework-arduinoespressif32@https://github.com/espressif/arduino-esp32.git#master platformio/tool-esptoolpy @ ~1.30100 ``` Pulling the latest compiler and Arduino core (without any source code changes to the core or the sketch) and re-uploading showed again that the blinky was not working (kinda expected). However, the behavior on the Serial monitor shows a different story. ```cpp Firmware start Timer seconds: 0.00 Timer alarm seconds: 6.42 Timer is alarm enabled: 1 Timer is started: 1 Timer seconds: 0.00 Timer alarm seconds: 6.42 Timer is alarm enabled: 1 Timer is started: 1 Timer seconds: 0.25 Timer alarm seconds: 6.42 Timer is alarm enabled: 1 Timer is started: 1 Timer seconds: 0.50 Timer alarm seconds: 6.42 Timer is alarm enabled: 1 Timer is started: 1 Timer seconds: 0.75 Timer alarm seconds: 6.42 Timer is alarm enabled: 1 Timer is started: 1 Timer seconds: 1.00 Timer alarm seconds: 6.42 Timer is alarm enabled: 1 Timer is started: 1 Timer seconds: 1.25 Timer alarm seconds: 6.42 Timer is alarm enabled: 1 Timer is started: 1 Timer seconds: 1.50 Timer alarm seconds: 6.42 Timer is alarm enabled: 1 Timer is started: 1 Timer seconds: 1.75 Timer alarm seconds: 6.42 Timer is alarm enabled: 1 Timer is started: 1 Timer seconds: 2.00 Timer alarm seconds: 6.42 Timer is alarm enabled: 1 Timer is started: 1 Timer seconds: 2.25 Timer alarm seconds: 6.42 Timer is alarm enabled: 1 Timer is started: 1 Timer seconds: 2.50 Timer alarm seconds: 6.42 Timer is alarm enabled: 1 Timer is started: 1 Timer seconds: 2.75 Timer alarm seconds: 6.42 Timer is alarm enabled: 1 Timer is started: 1 Timer seconds: 3.00 Timer alarm seconds: 6.42 Timer is alarm enabled: 1 Timer is started: 1 Timer seconds: 3.25 Timer alarm seconds: 6.42 Timer is alarm enabled: 1 Timer is started: 1 Timer seconds: 3.50 Timer alarm seconds: 6.42 Timer is alarm enabled: 1 Timer is started: 1 Timer seconds: 3.75 Timer alarm seconds: 6.42 Timer is alarm enabled: 1 Timer is started: 1 Timer seconds: 4.00 Timer alarm seconds: 6.42 Timer is alarm enabled: 1 Timer is started: 1 Timer seconds: 4.25 Timer alarm seconds: 6.42 Timer is alarm enabled: 1 Timer is started: 1 Timer seconds: 4.50 Timer alarm seconds: 6.42 Timer is alarm enabled: 1 Timer is started: 1 Timer seconds: 4.75 Timer alarm seconds: 6.42 Timer is alarm enabled: 1 Timer is started: 1 Timer seconds: 5.00 Timer alarm seconds: 6.42 Timer is alarm enabled: 1 Timer is started: 1 Timer seconds: 5.25 Timer alarm seconds: 6.42 Timer is alarm enabled: 1 Timer is started: 1 Timer seconds: 5.50 Timer alarm seconds: 6.42 Timer is alarm enabled: 1 Timer is started: 1 Timer seconds: 5.75 Timer alarm seconds: 6.42 Timer is alarm enabled: 1 Timer is started: 1 Timer seconds: 6.00 Timer alarm seconds: 6.42 Timer is alarm enabled: 1 Timer is started: 1 Timer seconds: 6.25 Timer alarm seconds: 6.42 Timer is alarm enabled: 0 Timer is started: 1 Timer seconds: 0.08 Timer alarm seconds: 6.42 Timer is alarm enabled: 0 Timer is started: 1 Timer seconds: 0.33 Timer alarm seconds: 6.42 Timer is alarm enabled: 0 ``` You can see that right off the bat, the `alarm seconds` value returns is suddenly.. 6.42? Which makes no sense since it should be 1.0. The timer seconds keep counting up until hitting 6.42, and then the alarm goes from enabled to disabled. Adding the `volatile` keyword to the struct definition as shown above does change the output. ``` Timer seconds: 0.00 Timer alarm seconds: 1.00 Timer is alarm enabled: 1 Timer is started: 1 Timer seconds: 0.25 Timer alarm seconds: 1.00 Timer is alarm enabled: 1 Timer is started: 1 Timer seconds: 0.50 Timer alarm seconds: 1.00 Timer is alarm enabled: 1 Timer is started: 1 Timer seconds: 0.75 Timer alarm seconds: 1.00 Timer is alarm enabled: 1 Timer is started: 1 Timer seconds: 0.00 Timer alarm seconds: 1.00 Timer is alarm enabled: 0 Timer is started: 1 Timer seconds: 0.25 ``` Now the timer seconds to read correctly as `1.00` but after 1 elapsed second, the alarm is just disabled and never continues... However from there, no matter where I add `volatile` in the register struct definition, I can not get it to function correctly. There might be additional issues somewhere else. In any case, I see this is a bug. For 1.0.6 it's a bug reproducable with PlatformIO and also fixable as I've shown, As for 2.0.0-alpha1 and the current master version, I see the same bug source (still no `volatile` on timer regs) but that is not the only needed thing to keep it going. Are you able to reproduce the issue in PlatformIO? Magically per the linked video, Arduino IDE seems to work with some versions though? Can anyone test this with the latest master?

it seems that edge interrupt does not work on ESP32, so giving false for edge in timerBegin would have done the job. Anyway I will add a “fix” for this in just a sec

And that warning was part of the change.

maxgerhardt · October 23, 2022, 11:55am

Does your sketch still work if you change true to false?

codehampster · October 25, 2022, 10:29pm

Many thanks for your prompt response…will try it and revert.

codehampster · November 13, 2022, 1:24am

Apologies for delays in responding…been dragged to a different task. Unfortunately, making the parameter false does not address the problem. it is still the same issue. Many thanks for your assistance.

maxgerhardt · November 13, 2022, 2:19am

Meaning the warning is still there but the code works? Or no warning but no working code?

codehampster · November 13, 2022, 2:36am

With flag true, the message appears but it actually works. with flag false, it does not. So it seems that it reports the message but it still works. Many thanks for helping me out.