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espcomm_sync error when uploading to ESP8266 board

PostPosted: Thu Dec 31, 2015 10:52 am
by Zach Sents
Hello everyone!

I've been trying to program the ever useful ESP8266 with the Arduino IDE, but when I try to upload, I get an error saying:

Code: Select allespcomm_sync failed
espcomm_open failed


I then just tried exporting the binary from the Arduino IDE and uploading it using esptool.py but that also gives me an upload failure. I'm using the ESP-01 module, so my pinout is as follows:

Image

I'm using a little USB FTDI board, and I'm powering the ESP using a 5V power brick and a 3.3V linear regulator specified to output 800mA. My connections from the ESP to the FTDI board are such:

TX -> RX
RX -> TX
GND -> GND
VCC -> 3.3V
CH_PD -> 3.3V
GPIO0 -> GND
GPIO2 -> LED -> ground
RST -> left open

Note: the GND on the ESP board and the FTDI board are both connected to ground on my external power supply.

I've triple checked my wiring and I can't figure out why my sketch won't upload. Thanks a bunch in advance.

Re: espcomm_sync error when uploading to ESP8266 board

PostPosted: Thu Dec 31, 2015 11:14 am
by martinayotte
GPIO2 -> LED -> ground


This prevent your ESP of booting properly !

If you wish to attach an LED on GPIO2, it need to be connected in Sink mode, not in Source mode, otherwise it is acting like a pull-down prevent booting.

Image
https://github.com/esp8266/esp8266-wiki ... ot-Process

Re: espcomm_sync error when uploading to ESP8266 board

PostPosted: Thu Dec 31, 2015 12:17 pm
by Zach Sents
martinayotte wrote:
GPIO2 -> LED -> ground


This prevent your ESP of booting properly !

If you wish to attach an LED on GPIO2, it need to be connected in Sink mode, not in Source mode, otherwise it is acting like a pull-down prevent booting.

Image
https://github.com/esp8266/esp8266-wiki ... ot-Process


Ahh okay thanks I'll give this a try! Thanks!

EDIT: Okay I tried that out and the sketch uploaded successfully! Thank you very much! However, now the board won't connect to the wifi. It just prints "Connecting to *****..." indefinitely. Any idea about what might be causing this?

Re: espcomm_sync error when uploading to ESP8266 board

PostPosted: Thu Dec 31, 2015 12:49 pm
by xtal
what FW did you load....
What code are you trying to run? [ did you set ssid, pw if needed]