ESP8266 Community Forum

Tried to plug into a (counterfeit)* Prolific USB to serial cable to an ESP8266 E01. I was getting the blue light to echo inputs from the serial terminal software which may not have been configured properly. I at no point received a response. I tried the standard baud rates but not the custom rate that has been reported by some. I' m just curious if any one has been able to establish serial comm with just a USB to serial cable? I plan to use an external power supply to overcome the current requirements for the radio but I thought it might be possible to just "talk" to the ESP8266 with a USB to serial 500ma.

OK you have to have the GPIO 0 and the ch PD pins High (5v) for the serial connection to work. I can verify that a prolific USB to serial cable with the correct wiring works. Case closed.

FWIW, I saw problems doing a firmware update with my prolific cable that were solved by going to an FTDI cable. The symptom was that the update would hang 5-10% of the way through and not recover. I've had problems with that cable in the last losing sync with back-to-back data, which there's plenty of in a long firmware update at 115.2k

mrb0y wrote:OK you have to have the GPIO 0 and the ch PD pins High (5v) for the serial connection to work.

High voltage should be 3.3V.

koliqi