Using the Arduino UNO board with the ESP8266 module with an empty sketch without calling any of the WiFi related functions produces an error during upload. Specifically during connection to the ESP module.
Board Setup/Connection
I have an Arduino UNO board, an ESP8266EX board and a level shifter (for 5V to 3.3V shift).
The connection is as follows:
Arduino UNO - ESP8266
- Digital Pin 0 (RX) - RX
- Digital Pin 1 (TX) - TX
- Gnd - Gnd
- 3.3V - VCC
- 3.3V - CH_EN
The Arduino UNO board is connected to my laptop (running the Arduino IDE) via the USB interface.
Installation
I followed the instructions in https://github.com/esp8266/Arduino#using-git-version-basic-instructions, the instruction within the repository for installation. After installation, I restarted the Arduino IDE 1.8.9 and selected the board (from Tools -> Board -> Generic ESP8266 Module (Under ESP8266 Boards 2.6.0 - DEV section).
Platform
Hardware: ESP8266
Core Version: 2.6.0-dev
Development Env: Arduino IDE
Operating System: Windows 8.1 64x
Settings in IDE
Module: Generic ESP8266 Module
Flash Mode: DOUT compitable
Flash Size: 1MB no SPIFFS
lwip Variant: v2 Lower Memory
Reset Method: ck
Flash Frequency: 40Mhz
CPU Frequency: 80Mhz
Upload Using: SERIAL
Upload Speed: 115200
Sketch
void setup() { }
void loop() { }
Debug Messages
esptool.py v2.6
2.6
esptool.py v2.6
Serial port COM4
Connecting........_____....._____....._____....._____....._____....._____.....____Traceback (most recent call last):
File "D:\Applications\Arduino\hardware\esp8266com\esp8266/tools/upload.py", line 25, in <module>
esptool.main(fakeargs)
File "D:/Applications/Arduino/hardware/esp8266com/esp8266/tools/esptool\esptool.py", line 2653, in main
esp.connect(args.before)
File "D:/Applications/Arduino/hardware/esp8266com/esp8266/tools/esptool\esptool.py", line 468, in connect
raise FatalError('Failed to connect to %s: %s' % (self.CHIP_NAME, last_error))
esptool.FatalError: Failed to connect to ESP8266: Timed out waiting for packet header
esptool.FatalError: Failed to connect to ESP8266: Timed out waiting for packet header
Additional Information
I tried the following actions:
- grounding the GPIO0 pin of the ESP8266
- connecting the GPIO1 pin to HIGH (VCC)
- swapping TX/RX connections between the boards