ESP8266 Community Forum

- Fri Dec 11, 2020 5:21 am #89749 Hello,

i'm newbie on esp8266 and i try to flash a esp-12S.

I have a nodemcuv3 with esp-12e:


I have hack this board to upload a arduino FW on my ESP12-S:


and this is my target:


but it doesn't work
On arduino, i choose Generic esp8266 (2.7.4) Board but this error message appear:

Code: Select allesptool.py v2.8
Serial port COM9
Connecting........_____....._____....._____....._____....._____....._____.....____Traceback (most recent call last):
  File "C:\Users\Maxime\AppData\Local\Arduino15\packages\esp8266\hardware\esp8266\2.7.4/tools/upload.py", line 65, in <module>
    esptool.main(cmdline)
  File "C:/Users/Maxime/AppData/Local/Arduino15/packages/esp8266/hardware/esp8266/2.7.4/tools/esptool\esptool.py", line 2890, in main
    esp.connect(args.before)
  File "C:/Users/Maxime/AppData/Local/Arduino15/packages/esp8266/hardware/esp8266/2.7.4/tools/esptool\esptool.py", line 483, in connect
    raise FatalError('Failed to connect to %s: %s' % (self.CHIP_NAME, last_error))
esptool.FatalError: Failed to connect to ESP8266: Timed out waiting for packet header

If somebody telle me how flash esp-12s I don't understand... maybe a hardware difference with ESP-12E?

Thank's

- Sat Dec 12, 2020 1:11 am #89755 is it up side down? the pins are same but the esp12 is on the other side?

- Sat Dec 12, 2020 1:51 pm #89770 The ESP-12S has all of the boot-mode resistors built into the module. By piggy-backing it onto a board designed for the ESP-12F, you've connected everything in parallel, so now you have ~ 6K pull-up and pull-down resistors, as well as an unknown with the reset line since you bypassed the NodeMCU reset circuit (two transistors + 2 resistors). I'd break that connection you have going to the switch and connect it to the pad on the board that goes to the RST castellation on the module,



I don't know how your board is designed, so don't know for sure where the reset switch is going to. Connecting that wire to the castellation pad has the best chance of working. You might also need to add a 100uF bulk bypass at the 3.3V/GND pins on the module due to those long wires. If the combined pull-up on the EN pin is too strong, you can just remove that wire going to the module pogo pins. It's pulled up both in the chip as well as the module, so you don't need anything on EN. That's only guaranteed with ESP-12S; the pull-up in the chip might be erratic if you try flashing an ESP-12F with that setup.

- Mon Dec 14, 2020 4:44 am #89786 Hello,

Thank's for your answer!

If i understand, i just need ftdi cable and esp12-s for flash him ? If yes, which config you use from arduino ?





It' more easier for me if i could juste use FTDI cable but i try todecrease cable size and desoldering EN pin!

Thank's for your help !!!