Saving Settings Without Damaging Flash

davedave94 · ‎2016-10-13

Posted on October 13, 2016 at 21:18

Hi guys,

SPWF01S is a new module for me. I have been using it for about a month.

My question is this: if I set the WiFi connection options at every boot and issue an AT&W (save), will it wear out the eprom memory? How do you guys handle configuring the module at boot?

Due to legacy design I am not using an ST processor :(

-Mr_E

#wifi

Gerardo GALLUCCI · ‎2016-10-16

Posted on October 16, 2016 at 23:45

Hi,

SPWF module embeds an STM32F1. On every AT&W command, a page is erased and written.

According to AN2594: ''

The STM32F10xxxâ€™s electrical characteristics guarantee 10 000 program/erase cycles per page.

''

http://www.st.com/content/ccc/resource/technical/document/application_note/ee/ef/d7/87/cb/b7/48/52/CD00165693.pdf/files/CD00165693.pdf/jcr:content/translations/en.CD00165693.pdf

Regards

jerry

jarno2 · ‎2016-10-18

Posted on October 18, 2016 at 14:21

Hi,

We have seen on few occasion bricked modules and we suspect that the reason is the settings management. With bricking I mean that the device no longer produces any output on the serial. I have not investigated in detail but reflashing the device works and restores serial port communication.

Our implementation is similar that it reconfigures the settings from the host during every boot. This probably has to be revised to rely on the device settings instead.

Gerardo GALLUCCI · ‎2016-10-18

Posted on October 18, 2016 at 22:20

Hi Jarno,

as far as I experienced, there are 2 ways to brick a module:

1) erase bootloader (placed @ address 0x08000000) -> after reset, cannot jump to application

2) poweroff device while saving (AT&W) -> before saving there is an erase...

Could it be option #2?

Best regards

jerry