ESP8266 Community Forum

So my NodeMCU 0.9 board finally arrived. Unfortunately I can´t program it using Arduino IDE 1.6.5 with ESP8266 support. I have tried multiple boards (generic, 0.9, 1.0) even fiddled with boards.txt to set resetmethod and tried both ck and nodemcu, neither worked. I thought its just broken board, but I tried flashing it with NodeMCU Flasher and it worked.

Still everytime I try to upload from Arduino IDE I get "espcomm_open failed" error. I tried multiple USB cables and ports but nothing worked. Does anyone has similiar problem or possible solution? Without using another flash tool? You know, programmers tend to be lazy...

Almost forgot to mention I use Win 10 and USB -> serial drivers installed automatically, and since NodeMCU Flasher works probably correctly.

odd seems to be a very common problem today....

Visit this link and be sure you are hooking things up correctly...

To the correct pins etc...

I don't know why someone would not want to use the flasher it is easy ...

But here is the link with the info...
http://www.esp8266basic.com/flashing-instructions.html

Yeah Flasher is nice tool, but its not as user friendly if you are using Arduino IDE with included esptool. I don´t have any additional wiring, beside this NodeMCU 0.9 board I have several standalone 01 chips and they work nicely. But the main reason I bought this board (nodemcu) is the implemented RTS DTR wiring which makes programming a breeze.

I made a little progress - if I plug in USB into the board while holding Flash button down and than upload my sketch it works. So I believe there is some issue with the RTS DTR restart method for esptool. I tried reinstalling USB <-> Serial drivers without any change at all. But since the Flasher works as expected I still believe the board itseld is working fine.

So, after little playing around I found solution to my problem .

I am using latest stable version of Arduino IDE for ESP which comes with esptool 0.4.5. So I checked latest compiled binaries and found newer version 0.4.6, which probably comes bundled with latest staging release. So I replaced binaries hoping there is no breaking change between the versions and tried to hit upload. With no success. So as a last option I copied the command from verbose upload output and changed the ck mode to nodemcu (I already tried this with previous version without any success) and it worked So I updated boards.txt accordingly and now I can happily upload sketches.

I can´t really tell what was causing the problems in the first place. Maybe nodemcu support was not included in the older version (but NodeMCU 0.9 board is supported), maybe there was some other problem, for example with Win 10, drivers... Only Igrr coul tell for sure