ESP32 Clockless issues

[tavrinnn]

Hardware: NodeMCU

My ESP32 crashes when attempting to invoke FastLED.Show(). The error message is as follows:
Guru Meditation Error: Core 0 panic'ed (Interrupt wdt timeout on CPU0)

This is using the latest clockless_esp32.h on the master branch.

I dug through the previous issues and used an earlier version of clockless_esp32.h and that version doesn't seem to crash. The only problem with that version though is that when you use all 8 channels it randomly hangs when attempting to show().

Here is the link to that version: https://raw.githubusercontent.com/samguyer/FastLED/master/platforms/esp/32/clockless_esp32.h

[Ma5t3rful]

Hardware: ESP32 Dev Module
IDE :1.8.5

i have this problem too please help.

[Ma5t3rful]

yeah i got it
add this code to the first line of your project (even the "#include <FastLED.h")
#define FASTLED_ALLOW_INTERRUPTS 0
thanks to @marcmerlin
he solved this problem. but what does this code mean? does it disable the interrupts?

[marcmerlin]

FASTLED_ALLOW_INTERRUPTS 0
turns off interrupts while LEDs are being updated. You still get interrupts after the strip had been updated, but not during.
Why you need this on ESP32, no idea. ESP32 is very cool, but also complicated, and gives crashes that are not always what you expect (like the wrong version of FastLED causing crashes in totally unrelated library code)
You should talk to @samguyer since you are using his version of the code which should work on ESP32 (I have used it to display on a 32x32 matrix (neopixel yesterday, and it worked ok for me without disabling interrupts)

[samguyer]

@marcmerlin @Master811129 @tavrinnn

Hi all! You should not need to worry about disabling interrupts at all using my implementation of clockless_esp32.h, (which is now the default provided in the master branch of FastLED). In fact, I'm pretty sure that the FASTLED_ALLOW_INTERRUPTS directive is not used anywhere in the code.

Also: the latest version can support any number of strips -- it assigns them to the eight available RMT channels on-the-fly using a simple worklist algorithm.

One very useful utility for ESP32 problems is the ESP exception decoder. I highly recommend it:

https://github.com/me-no-dev/EspExceptionDecoder

Feel free to ping me if you are still having problems!

[tavrinnn]

As @samguyer said above, disabling interupts won't achieve anything in the clockless_esp32 block as his implementation uses the RMT module to generate the precisely timed parallel led timings.

@samguyer what version of clockless_esp32 should I be using? the version on the master branch? I'll give the exception decoder a go and see what happens too

[samguyer]

@tavrinnn The current version in the main FastLED branch is good, although I have some updates that should be merged in soon (waiting on a pull request!). If you want the latest-and-greatest you can use my branch.

[tavrinnn]

Cheers, I'll give it a go and report back

[samguyer]

It probably won't matter much. The main differences I've made recently are in the fastpin definitions for use in clocked chips, like the APA102s.

[tavrinnn]

Alright so I spent the whole afternoon playing with your latest master branch @samguyer
I also added the ESP32 Exception handler toolset to the Arduino IDE.

Below is what I got when the ESP32 crashes:

PC: 0x400e24bc: ClocklessController13, 60, 150, 90, (EOrder)10, 0, false, 5>::interruptHandler(void*) (C:\Program Files at x86)\Arduino\libraries\FastLED_ESP32/platforms/esp/32/clockless_esp32.h line 411
EXCVADDR: 0x00000000

Decoding stack results
0x400e24bc: ClocklessController13, 60, 150, 90, (EOrder)10, 0, false, 5>::interruptHandler(void*) (C:\Program Files at x86)\Arduino\libraries\FastLED_ESP32/platforms/esp/32/clockless_esp32.h line 411

[tavrinnn]

I have managed to narrow the problem down a bit more

If WiFi.begin() isn't called, FastLED.show() will run flawlessly with the current clockless_esp32 implementation. However, the moment WIFI.begin() gets invoked, the chip will randomly crash when invoking FastLED.show().

Interestingly, the stack trace is only displayed when the FastLED.show() task is assigned to Core0. When I assign it to core 1 no stack trace is displayed - the chip simply just locks up entirely and becomes unresponsive.

I can provide a test sketch to replicate the problem if required.

[samguyer]

@tavrinnn If you can send me a sketch that reproduces the problem, that would be great. It's surprising that you're seeing this problem even when FastLED runs on the other core. I'll check it out.

[tavrinnn]

#include <FastLED.h>
#include <WiFi.h>

#define MAX_BRIGHTNESS 10
#define MAX_PIXEL_CHANNELS 8
#define MAX_PIXELS_IN_ROW 144
CRGB led_buff[MAX_PIXEL_CHANNELS * MAX_PIXELS_IN_ROW];

#define FAST_LED_REFRESH_CORE 0

static TaskHandle_t FastLEDRFTH;
static TaskHandle_t MainTH;
static int FastLEDDelay;

unsigned long frameTime;
uint8_t gHue = 0;

WiFiUDP udpServer;

void simpleRefresh( int delayMS )
{
MainTH = xTaskGetCurrentTaskHandle();
FastLEDDelay = delayMS;
xTaskNotifyGive(FastLEDRFTH);
ulTaskNotifyTake(pdTRUE, portMAX_DELAY);
}

void FastLEDRefreshFrame( void *pvParameters )
{
unsigned long fStart, fEnd;

while (1)
{
fStart = micros();
ulTaskNotifyTake(pdTRUE, portMAX_DELAY);
FastLED.show();

if (FastLEDDelay > 0)
  FastLED.delay(FastLEDDelay);

xTaskNotifyGive(MainTH);
fEnd = micros();
frameTime = fEnd - fStart;

}
}

void setup() {
Serial.begin(921600);

FastLED.addLeds<WS2812B, 13, GRB>(led_buff, 0, MAX_PIXELS_IN_ROW);
FastLED.addLeds<WS2812B, 12, GRB>(led_buff, 1 * MAX_PIXELS_IN_ROW, MAX_PIXELS_IN_ROW);
FastLED.addLeds<WS2812B, 14, GRB>(led_buff, 2 * MAX_PIXELS_IN_ROW, MAX_PIXELS_IN_ROW);
FastLED.addLeds<WS2812B, 27, GRB>(led_buff, 3 * MAX_PIXELS_IN_ROW, MAX_PIXELS_IN_ROW);
FastLED.addLeds<WS2812B, 26, GRB>(led_buff, 4 * MAX_PIXELS_IN_ROW, MAX_PIXELS_IN_ROW);
FastLED.addLeds<WS2812B, 25, GRB>(led_buff, 5 * MAX_PIXELS_IN_ROW, MAX_PIXELS_IN_ROW);
FastLED.addLeds<WS2812B, 19, GRB>(led_buff, 6 * MAX_PIXELS_IN_ROW, MAX_PIXELS_IN_ROW);
FastLED.addLeds<WS2812B, 22, GRB>(led_buff, 7 * MAX_PIXELS_IN_ROW, MAX_PIXELS_IN_ROW);
FastLED.setBrightness(MAX_BRIGHTNESS);
xTaskCreatePinnedToCore(FastLEDRefreshFrame, "FastLEDRefresh", 2048, NULL, 2, &FastLEDRFTH, FAST_LED_REFRESH_CORE);

// WiFi init causes crashes on FastLED.show() (Line 411 in Clockless_ESP32.h)
WiFi.softAP("ESP32", "12345678");
WiFi.setSleep(false);
udpServer.begin(2302);
}

void rainbow() {
for (int i = 0; i < MAX_PIXEL_CHANNELS; i++) { fill_rainbow(led_buff + (i * MAX_PIXELS_IN_ROW), MAX_PIXELS_IN_ROW, gHue, 7); }
}

void loop() {
rainbow();
simpleRefresh(1);
EVERY_N_MILLISECONDS(10) { gHue++; }
}

[samguyer]

Ok, I'll try it out today and let you know what I find.

[tavrinnn]

No worries. Thanks :D

[samguyer]

@tavrinnn I tried your code, and I was able to reproduce the crash you described. Interestingly, it only happens when FastLED.show() is running on the other core (Core 0), while the main thread and the WiFi are running on Core 1. When I run everything on Core 1, it seems to work fine. That makes me think it has more to do with synchronization than interrupts.

So, I tried starting with the DemoReelESP32 example that I added to the examples directory. I made sure it spawned the show task on Core 0, and added the WiFi initialization, and it seems to work. Maybe grab the task functions from that code and paste them into your code.

Let me know how it goes.