ESP32 Forum

I have code that puts the ESP32 to light sleep with a timer (10s) and wakes it up. The code works as intended on the ESP32-WROOM32D, but it fails in ESP-WROOM32 (older, no D)

The failure appears to be that the (no D) chip does not go to sleep, and the RTC timer {WD} resets the system; [Confirmed it with an Amp Meter]

rst:0x10 (RTCWDT_RTC_RESET),boot:0x13 (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:1
load:0x3fff0030,len:4
load:0x3fff0034,len:4812
load:0x40078000,len:13840
load:0x40080400,len:3132
entry 0x40080600
I (272) cpu_start: Pro cpu up.
I (272) cpu_start: Starting app cpu, entry point is 0x40081058
0x40081058: call_start_cpu1 at /home/peterglen/esp/esp-idf.4.3/components/esp_system/port/cpu_start.c:124

I tried to disable the RTC timer, no change; but, when I extend the RTC timer's wachdog interval, it extends the reboot interval.

The sleep code does not contain anything special; just calling the API-s as normal.

gl_light_milli is set to 10
esp_err_t errw = esp_sleep_enable_timer_wakeup(gl_light_milli * 1000);
esp_light_sleep_start();
// wake code ... just a printf etc

This works well on the WROOM32D / DevKitC V4; does not work on the WROOM32 / DevKitC V2;

I am curious if there be an insight why this is happening, and solution to this. Thank you;

Peter Glen

More info:

IDF version:

ESP-IDF: v4.3-dev-1720-g494a124d9

I upgraded from a 3.x , same error on both IDF versions.

Do you know if the older chip is rev0?

Same light sleep problem here with ESP-WROOM-32 module. Is it possible to identify the problem and even provide a workaround?

Hi,

Did you find the solution? I am running into the same problem.

Thank you so much!

Best

I'm getting the same problem. Code works fine with no sleep.
When I use Light Sleep, after a variable number of sleep/wake cycles, the WDT causes a reset.
Tried many many of the solutions and workarounds shown around the net but nothing seems to work.
I've just found this reply to another post:
https://github.com/espressif/esp-idf/issues/11315
which suggests adding:-
REG_SET_FIELD(RTC_CNTL_BIAS_CONF_REG, RTC_CNTL_DBG_ATTEN, 3);
There is no explanation what this is doing but I've put it in my setup code to see what happens.
As we speak I haven't had an RTCWDT reset yet after 15 mins which is a good sign, but not conclusive, and I am wary as to what this line of code may have also affected. I'll be conducting a bunch of tests to make sure the WDT still fires when it should as disabling it is not something I want to do!
Does anyone know what this code does?

Re last post: I spoke too soon. It still reset but took 20 mins this time - a bit longer than usual but the problem is still there!

Hi

I am disabling Ble and restarting BLE after sleep, but my problem is reinitialization takes time.

Does disabling BLE before light sleep stop the reset problem?

Were you ever able to solve this issue?

Simply put BLE & Light Sleep has been broken since 4.4.x and still is here on 5.2.1.

Intermittet crashes with RTCWDT_RTC_RESET.

I've tried everything from "extra crystal current" to other boards, and everything in between. Something is just wrong and the CPU doesn't wake from sleep.

Anyone from Espressif?