ESP8266 Community Forum

- Sun Jul 05, 2015 12:50 pm #22496 I think I have destroyed my ESP8266....

I have a ESP8266-201 board that I want to connect to my Acorn Atom. However, my Atom is way to slow to handle communications at 115200 baud. My AT firmware didn't have any command to change the baud rate.

The documentation in http://bbs.espressif.com/download/file. ... 25226e7379 says there is an AT+UART command to set the baud rate. In my firmware (V0.17) there wasn't any AT+UART command. So I decided to update to Espressif's V0.20 firmware.

Updating seems soooooo easy, but is soooooo hard to do....

I downloaded the new firmware files from https://github.com/espressif/esp8266_at/tree/master/bin
I connected GPIO01 to ground.
I connected GPIO02 to VCC (=3.3v)
I started the esptool.py to flash the device -> failed to connect
Several attempts, several baud rates, no luck

Then I connected GPIO01 also to GND and CHIP_EN to VCC.

YES! It connected, flashed my device, started writing the new firmware files....

and stuck at 7%.
When I trie to re-flash the device -> failed to connect

And now there's nothing left except a small piece of PCB with a red shining led.
And the most frustrating part of this story:

Code: Select allpeppermint Downloads # strings user1.bin | grep -i gmr
+GMR
peppermint Downloads # strings user1.bin | grep -i gslp
+GSLP
peppermint Downloads # strings user1.bin | grep -i uart
peppermint Downloads #

There doesn't seem to be any AT+UART command in the latest firmware.

But first things first, is there any way to get some usable firmware back into my module? I tried to find one on the forum but either it's not here or I used the wrong search terms.

Any ideas or suggestions?

Regards,
Roland


_________________
6502 Inside

6502 Inside

- Sun Jul 05, 2015 11:36 pm #22538 Hi,
what do you use as a converter ? is it by the way FT232RL Serial adapter ?

- Mon Jul 06, 2015 1:23 am #22542 Hi,

I'm using a PL2303 based serial adapter. The wifi module is powered with an external 3.3V power supply and the TX from the adapter is adjusted with a 1.8k/3.3k resistor network.

The communication between my laptop and the wifi module was fine, I could execute AT commands and I received a response. IMHO I cannot flash it normally because the firmware has been erased so the processor in the ESP8266 doesn't have any code to execute.

Regards,
Roland

6502 Inside

- Mon Jul 06, 2015 3:35 am #22546 For power you need 3.3v (more or less) at up to 500mA peak but mostly under 100mA. Using 3xAA NiMH is a bit high but (in my experience) safe. Don't plan on using it this way long term though.

For normal operation you always need
GPIO15 -> GND
CH_PD <-> VCC
When not flashing you need nothing else connected. Naturally VCC/GND/TX/RX arsomee also attached...
On reset boot messages show at 74880 baud. Do you see these? If yes then it is probably not bricked.

To flash you connect
GPIO2 <-> GND
and on reset you will not see the same startup messages, only a couple of garbage characters. You can now start the flash utility (it usually sets the correct baud rate by itself).

To enable wakeup from deep sleep you also want
GPIO16 <-> REST

Good luck.