zioax wrote:Hi, today i've received the esp-03, I've put it into a breadboard for an easily pin access.
Tied CH_PD to VCC (without pull-up) GPIO_0 and 15 both to GND.
Esptool say "Failed to connect", where is the problem? Maybe it's broken?
The little ESP units usually come with some version of the AT firmware already flashed. Have you connected up to your USB/serial adaptor and just tried to run the board with the AT firmware - watching the info when the ESP-03 boots up and typing in some basic AT commands? This is the easiest way to confirm your USB/serial adaptor is properly set up and working, right COM port and baud rate, etc.