ESP32 stops working for no apparent reason in field

Kalyan
Posts: 5
Joined: Thu Jun 20, 2019 7:43 am

ESP32 stops working for no apparent reason in field

Postby Kalyan » Thu Jun 20, 2019 9:12 am

Hi,

I am using ESP32 Wroom in a product. After a month of operation the devices stops working. We find that the device does not boot. If I try to flash ESP32, I am getting the error following. The devices were purchased from a reputed online vendor.

esptool.py v2.3.1
Connecting........_____....._____....._____....._____....._____....._____....._____....._____....._____....._____
A fatal error occurred: Failed to connect to ESP32: Timed out waiting for packet header

I am flashing from Command prompt with following command.
C:\Project\SLC>"C:\Project\SLC"\esptool.exe --chip esp32 --port com27 --baud 921600 --before default_reset --after hard_reset write_flash -z --flash_mode dio --flash_freq 80m --flash_size detect 0xe000 "C:\Project\SLC"\boot_app0.bin 0x1000 "C:\Project\SLC"\bootloader_qio_80m.bin 0x10000 "C:\Project\SLC"\controller.ino.bin 0x8000 "C:\Project\SLC"\controller.ino.partitions.bin

Replacing ESP32 fixes the problem. I believe its a reliability issue with ESP32, has anybody faced such reliability issues with ESP32 Wroom?

nevercast
Posts: 7
Joined: Tue Jan 08, 2019 2:58 am

Re: ESP32 stops working for no apparent reason in field

Postby nevercast » Thu Jun 27, 2019 11:58 pm

What is the environment that the device is deployed in? How is it enclosed? Could mositure damage or other harsh conditions be a possibility ?

ESP_Angus
Posts: 2344
Joined: Sun May 08, 2016 4:11 am

Re: ESP32 stops working for no apparent reason in field

Postby ESP_Angus » Fri Jun 28, 2019 12:13 am

Hi Kalyan,

This seems very unusual. Has it happened to more than one device?

As nevercast suggests, this may be possible if physical conditions have damaged the WROOM module in some way.

How are you resetting the WROOM into bootloader mode? If you connect a serial program at 115200bps and look at the serial output from the device while resetting it manually, do you see any output?

Kalyan
Posts: 5
Joined: Thu Jun 20, 2019 7:43 am

Re: ESP32 stops working for no apparent reason in field

Postby Kalyan » Sat Jun 29, 2019 6:23 am

nevercast wrote:
Thu Jun 27, 2019 11:58 pm
What is the environment that the device is deployed in? How is it enclosed? Could mositure damage or other harsh conditions be a possibility ?
Hai nevercast,
I am using IP65 box. Box will expose to sunlight. Inside box temperature is up to 55 degree Celsius and no moisture.

Kalyan
Posts: 5
Joined: Thu Jun 20, 2019 7:43 am

Re: ESP32 stops working for no apparent reason in field

Postby Kalyan » Sat Jun 29, 2019 8:10 am

Hai ESP_Angus,
This has happened to six to nine devices out of 148. At 115200bps I got 3 different results in nine devices.
  • In one device it is printing following message continuously.
    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:0x3fff0018,len:4
    load:0x3fff001c,len:952
    load:0x40078000,len:6084
    load:0x40080000,len:7936
    csum err:0x37!=0xd7
    ets_main.c 371
    ets Jun 8 2016 00:22:57
  • In two devices it is printing following message continuously.
    rst:0x10 (RTCWDT_RTC_RESET),boot:0x13 (SPI_FAST_FLASH_BOOT)
    flash read err, 1000
    ets_main.c 371
    ets Jun 8 2016 00:22:57
  • In 6 devices it is not print anything.
How are you resetting the WROOM into bootloader mode?
Please check below schematic.
Attachments
Schematic.png
Schematic.png (82.76 KiB) Viewed 12855 times

rodmcm
Posts: 65
Joined: Sat Sep 02, 2017 3:31 am

Re: ESP32 stops working for no apparent reason in field

Postby rodmcm » Wed Jul 03, 2019 4:13 am

Looks like a continuous reset. Perhaps a pull up resistor on the Reset line.

WiFive
Posts: 3529
Joined: Tue Dec 01, 2015 7:35 am

Re: ESP32 stops working for no apparent reason in field

Postby WiFive » Wed Jul 03, 2019 5:09 am

No protection on 12v input?

Kalyan
Posts: 5
Joined: Thu Jun 20, 2019 7:43 am

Re: ESP32 stops working for no apparent reason in field

Postby Kalyan » Thu Jul 04, 2019 8:06 am

No protection on 12v input?
Hai,
12v input is from SMPS. Which protection is needed?

Kalyan
Posts: 5
Joined: Thu Jun 20, 2019 7:43 am

Re: ESP32 stops working for no apparent reason in field

Postby Kalyan » Thu Jul 04, 2019 8:11 am

Looks like a continuous reset. Perhaps a pull up resistor on the Reset line.
Hai,

I didn't understand what you are telling, can you please elaborate?

woofy!
Posts: 21
Joined: Tue Oct 03, 2017 12:02 pm

Re: ESP32 stops working for no apparent reason in field

Postby woofy! » Thu Jul 04, 2019 8:50 am

I would suspect a power supply issue with an unstable 3v3 seeing much higher spikes.
There is no series diode on the input to the regulator. Use a schottky or fast recovery diode.
There is no protection on the 12v. I would use a transzorb or TVS diode across the 12v supply, and include a fuse too.
The 0.01uF input capacitor on its own is useless, use 470uF-680uF as well.

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