Author Topic: ESP8266 ESP07 Brownout Clears Flash?  (Read 976 times)

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Offline itdontgoTopic starter

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ESP8266 ESP07 Brownout Clears Flash?
« on: January 20, 2020, 11:33:32 am »
We've been using these ESP07 modules and have had a few problems with them. To avoid another step in production we're just using the standard AI Thinker firmware which is good enough. However, I've come across a few now that seem to lose their memory. They're tested working fine and then sometimes they don't boot... and once this has happened it won't work again until it's been re-flashed. They're likely to have been browned out. It's sort of repeatable if we slowly bring the power up.
Has anyone come across this. Is there a way to protect the flash memory?
They're still working as they attached to the router and the boot loader output works but the AT commands don't work.

Offline nuclearcat

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Re: ESP8266 ESP07 Brownout Clears Flash?
« Reply #1 on: May 06, 2020, 05:50:42 am »
Holding CH_PD and/or RST of module by supervisor IC?
 

Offline kripton2035

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Re: ESP8266 ESP07 Brownout Clears Flash?
« Reply #2 on: May 06, 2020, 07:36:33 am »
it is well known that some cheap esp modules comes with a crappy flash memory chip.
it is a good practice to change the eeprom chip inside with a reputable brand one bought from a reputable dealer like mouser or digikey or RS
and also install a bigger one so that you can use OTA programming that you can't do with standard 4Mb chip.


I also had very strange results from an esp module that I feded with 5v signals on certain pins without knowing it
it worked for hours then rebooted with no reason. also the power supply must be as good and stable 3v3 as possible.
« Last Edit: May 06, 2020, 07:38:34 am by kripton2035 »
 

Offline nuclearcat

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Re: ESP8266 ESP07 Brownout Clears Flash?
« Reply #3 on: May 06, 2020, 10:29:46 am »
it is well known that some cheap esp modules comes with a crappy flash memory chip.
it is a good practice to change the eeprom chip inside with a reputable brand one bought from a reputable dealer like mouser or digikey or RS
and also install a bigger one so that you can use OTA programming that you can't do with standard 4Mb chip.


I also had very strange results from an esp module that I feded with 5v signals on certain pins without knowing it
it worked for hours then rebooted with no reason. also the power supply must be as good and stable 3v3 as possible.
ESP-07 have nasty metal lid, that is much harder than just resolder flash chip.
 

Offline kripton2035

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Re: ESP8266 ESP07 Brownout Clears Flash?
« Reply #4 on: May 06, 2020, 11:43:05 am »
ESP-07 have nasty metal lid, that is much harder than just resolder flash chip.
it is easy to remove them using cheap hot air station, and also to place them back. I do it each time I have a new esp07 coming.
 
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