ESP8266 Community Forum

- Fri Feb 22, 2019 1:19 pm #80731 Hi there,

Thank you for reading me.

I own 5 ESP 01 (some seems from 1st generation (without resistors etc.))

Things worked for some at the beginning.

But now, I'm unable to upload any sketch and get espcomm_ errors for all modules

I tryed with several computer (Arduino IDE well configured)
Arduino IDE serial monitor tells:
boot mode 3,7
or boot mode 3,6
...
Things seem clear : the modules stay in flash mode (mode to execute application from flash, not for boot loading which is flash programming.
https://arduino-esp8266.readthedocs.io/en/latest/faq/a01-espcomm_sync-failed.html

Nothing does it.
Adding resistors, change circuit, I've done a lot, had a look at several tutorials, followed Kolban ebooks etc.
Tryed with Arduino UNO or Duemilanove as UART interface, or still with FTDI Module

What I'm missing ??

So ... is there a way to reinitialize those MCU?


Configuration
Arduino 1.8.8
Ubuntu 18 LTS on MacPro 2008

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- Sat Feb 23, 2019 4:19 am #80742 at least for the breadboard setup I have 2 suggestions:

°) the pull-up on reset is definitely not going to Vcc
°) can only assume direct connect of gpio2 to Vcc, suggest change to resistor (pull-up)
°) can't see value of pull-ups, 4k7 or 10k should be good
°) what type of 3V3 regulator are you using? 300mA is min

boot order for flash should be:
press and hold gpio0 button,
press and release reset button,
release gpio0 button

do not forget to do hw reset or power off/on after flash!

for flashing with the simple usb-esp01 adapter one should select reset method ck

- Tue Feb 26, 2019 4:23 am #80811

Things worked for some at the beginning.

But now, I'm unable to upload any sketch and get espcomm_ errors for all modules

Their life didn't start off in a 5V environment, did they?

In the end you will kill an ESP8266 if you supply it with more than 3.3V±10%

Assumption is the mother of all f*ckups. At least: that's what I'm assuming.