Need help for Battery Support with ESP32-WROVER Module

[Ritesh]

Hello Team,

We are using ESP32 Modules and chips since many years into different IoT Products which works fine without any issue so far with external supply.

Now, We have designed one product which is operating over battery and found one critical issue which is below.

When Battery goes into discharge state at that time ESP32 Module stops working but strange thing is like there is no any sorting between VCC and GND.

We didn't use the supervisor IC and our battery haven't BMS features as well, so ESP get the below 2.3 V.

After this scenario we have observed that ESP not boot up. We have also observed 3.3V on pin number 25(GPIO0) instead of 1.8V (As per wrover module design) . Let us know how to recover the ESP from this scenario.

Let me know if anyone has faced this type of issues when they have operated product with battery but without BMS support.

Also let me know if need anything else from my end.

[Ritesh]

Hello Team,

Let me know if anyone has any feedback or suggestions for the same.

[WiFive]

Why should gpio0 have 1.8v?

Afaik the only way to exit stuck state is to pull en pin low until voltage is good.

[Ritesh]

Why should gpio0 have 1.8v?

Afaik the only way to exit stuck state is to pull en pin low until voltage is good.

Hello WiFive,

We have just compared GPIO0 voltage with working board and non working board and found that working board has 1.8V on GPIO0 while non working board has 3.3V on GPIO0.

Also we have applied external supply instead of battery supply for non working but still not getting any success.

There are almost 100 boards in which we have faced this type of issues while using Li-ION 3.7 mV Battery at customer end which is critical for us as we have started EV domain into last year and facing this type of critical issue.

Also strange thing is like only ESP32-WROVER-I module is damaged while STM32 Module is not damaged which is working fine without any issue.

Please find below logs which we are getting

rst:0x10 (RTCWDT_RTC_RESET),boot:0x1f (SPI_FAST_FLASH_BOOT)
invalid header: 0xffffffff
invalid header: 0xffffffff
invalid header: 0xffffffff
invalid header: 0xffffffff
invalid header: 0xffffffff
invalid header: 0xffffffff
invalid header: 0xffffffff
ets Jul 29 2019 12:21:46



rst:0x10 (RTCWDT_RTC_RESET),boot:0x1f (SPI_FAST_FLASH_BOOT)
invalid header: 0xffffffff
invalid header: 0xffffffff
invalid header: 0xffffffff
invalid header: 0xffffffff
invalid header: 0xffffffff
invalid header: 0xffffffff
invalid header: 0xffffffff
ets Jul 29 2019 12:21:46



rst:0x10 (RTCWDT_RTC_RESET),boot:0x1f (SPI_FAST_FLASH_BOOT)
invalid header: 0xffffffff
invalid header: 0xffffffff
invalid header: 0xffffffff
invalid header: 0xffffffff
invalid header: 0xffffffff
invalid header: 0xffffffff
invalid header: 0xffffffff
ets Jul 29 2019 12:21:46



rst:0x10 (RTCWDT_RTC_RESET),boot:0x1f (SPI_FAST_FLASH_BOOT)
invalid header: 0xffffffff
invalid header: 0xffffffff
invalid header: 0xffffffff
invalid header: 0xffffffff
invalid header: 0xffffffff
invalid header: 0xffffffff
invalid header: 0xffffffff
ets Jul 29 2019 12:21:46

So, Do you have any idea like what can be the issue or how to debug it?

Let me know if need anything else from my end.

[Ritesh]

Why should gpio0 have 1.8v?

Afaik the only way to exit stuck state is to pull en pin low until voltage is good.

Also we have tried with this way but didn't get any success after pulling en pin to LOW with external power supply.

Let me know if any other suggestion to recover it.

[WiFive]

Isn't wrover-i supposed to be bootstrapped to 1.8v or did you set efuse? Is it first generation wrover or B or E version?

Did you dump the flash? Did you try reprogramming? Did you check flash status registers?

Is this a different design than your other thread with boot failure?

[Ritesh]

Isn't wrover-i supposed to be bootstrapped to 1.8v or did you set efuse? Is it first generation wrover or B or E version?

Did you dump the flash? Did you try reprogramming? Did you check flash status registers?

Is this a different design than your other thread with boot failure?

Hello,

Sorry, Actually Module is ESP32-WROVER not ESP32-WROVER-I which is written by mistake. We have also tried to set up 1.8V Bootstraped using EFUSE but then after not able to program firmware into flash memory.

Yes. we have dumped Flash Memory and no any difference or garbage data found into flash memory which means no any corruption found into it.

Also we hav tried to reprogram before changing 1.8v bootstraped and able to flash program successfully without any issue

Also we have checked flash status registsres of non working and compared with working board which seems to be fine.

Yes. it is same design for another thread which is on going.

Let me know if need anything else from my end.

[WiFive]

ESP32-WROVER and ESP32-WROVER-I are first generation 1.8v
ESP32-WROVER-B and ESP32-WROVER-IB are second generation 3.3v
ESP32-WROVER-E and ESP32-WROVER-IE are third generation 3.3v

I don't know if running at wrong vddsdio voltage may contribute to your problems.

I think you need to wait for espressif hardware analysis that you sent them schematics and samples.

[Ritesh]

ESP32-WROVER and ESP32-WROVER-I are first generation 1.8v
ESP32-WROVER-B and ESP32-WROVER-IB are second generation 3.3v
ESP32-WROVER-E and ESP32-WROVER-IE are third generation 3.3v

I don't know if running at wrong vddsdio voltage may contribute to your problems.

I think you need to wait for espressif hardware analysis that you sent them schematics and samples.

Hello,

I don't understand like wrong vddsdio voltage statement because it is working fine into normal case and then suddenly stops working once battery is going to drain it.

Yes. We have already provided one board to Espressif Team for Analysis perspective.

But i just want to know do you have any idea like how it is happened as per logs I have provided into last thread.

[WiFive]

It may work fine at wrong voltage for a while, but also may damage flash over time if it is above rated voltage. I cannot say whether it is connected to your problem but it is something to ask espressif about. Other than that I don't have any suggestion, sorry.

I don't know what idf version you are using but there was some fix to raise 1.8v regulator output in the past to solve some flashing issues.