Can't download sketches to ESP8266

I’ve added support to IDE 1.6.3 for the ESP8266. I’m able to talk to it using AT commands via the debug console at 115200 baud, got it to join my wireless network, etc. What I can’t do is download sketches. I ground gpio0 before powering up as per instructions (I think), and I see the TX light blink on the FTDI converter, but I am unable to download a sketch. The usual error is a sync error. I have the IDE port set and the download speed 115200. Any idea what I might be doing wrong?

The ESP8266 is not an Arduino so you will probably have better luck asking at the site that provides the ESP8266 add-on software.

True, but the Adafruit ESP8266 support includes an AVR core and should be completely compatible with the Arduino IDE. At least that's how it's advertised. The board shows up on the boards list and the port shows up as COM27. I can use the debug console as a terminal emulator to send and receive AT commands. The firmware is not what comes with Adafruit's breakout board, so I'm thinking maybe it's the bootloader.

What USB-to-Serial cable are you using?

Does the red light come on dimly when you put the board in bootload mode by holding down the GPIO0 button while pushing the Reset button?

Are you following the adafruit tutorial? https://learn.adafruit.com/adafruit-huzzah-esp8266-breakout/using-arduino-ide

I'm using a generic FTDI converter with switchable 3.3v/5v power (using 3.3v). Loopback and AT commands/responses work. I did follow the Adafruit tutorial, but I believe the firmware's not what's on my bare bones module, and I can't update the firmware for whatever reason I have not yet discovered. I got word today my Adafruit board was shipped, I'm certain it will work with the IDE. I was hoping to get a jump start by using just a module with minimal support circuitry.

The board does not have an LED connected to the same port as the Adafruit board, but it does go into d/l mode as evidenced by a single flash of one of the LED's, as documented elsewhere. I see the TX LED on the FTDI board attempting to send, but there's no response from the ESP8266, and eventually it gives up. Although you do get a lot for $10 from the Adafruit board, $3 or less using a generic module is hard to resist for wireless sensors in my home. I hope I get this working at some point. Any help would be appreciated.

I'm going to ask my standard leading question for ESP8266 beginners: How are you providing power to the module?

Good question. Of course I first tried using the FTDI’s 3.3v output, but I quickly switched to an external 3.3v 1A supply.

I’m kind of discounting power issues because it does find and connect to my secure WLAN without a problem, responds to pings, is seen (when set to STA and AP) by my phone as a wireless hotspot and of course responds to AT commands.

The answer was to remove 1.6.3 and %APPDATA%\arduino15, do a clean non-admin install of 1.6.4, add Adafruit's URL to the 3rd party board list. The IDE is fully functional with the Adafruit breakout board and I assume with the basic module if you provide external power and level shifting.

Note that once the Arduino core is loaded, the AT or LUA commands will no longer work, and sketches have to be written using the WiFi Shield library with a few application-level mods. You can always burn the AT or LUA firmware back onto the board though.