ESP8266 Community Forum

Thanks for the reply. Was wondering if it could be done with the Mega board shorthing the reset pin so it keeps the MCU from booting and being an annoyance in the serial line, as you suggested. But this seems to enable the pullup in the RX pin of the mega8u2, reading 5V while idle when it should be high Z. This makes voltage translation a pain since you have to use a CMOS buffer.

Another option would be bridging the UART0 with any other UART blocks the Mega has available, via software. But nevermind, your method works and already ordered a USB-TTL converter.

Will this work with an ESP-12 loaded with NodeMCU 0.9, or should it be the AT firmware?

Right now I can program my ESP-12 running NodeMCU firmware with Esplorer, this works fine.

However, if I want to program it from the Arduino IDE, either using Generic ESP8266 Module or NodeMCU 0.9 (ESP-12 Module), I receive an error when uploading that says


I have tried with two different USB-TTL devices (CH340G, TL2303) and also with an Arduino Uno (all works fine when uploading lua code in Esplorer). I tried with both internal and external power supply, and 3.3v and 5v, and on three different ESP-12 modules.

Kinda annoying, what am I missing?

Setup
Arduino IDE 1.6.7
Board Manager: ESP8266 v2.2.0
ESP8266 ESP-12 running NodeMCU 0.9 Integer

Had same problem. I used 2 AA bateries like explained herehttp://www.arduinesp.com/blink-manual-flash