ESP8266 Community Forum

- Mon Dec 14, 2015 7:35 am #36392 Hi all,

I've some problem to communicate with ESP.
I've wired ESP to FTDI using this guide:

http://www.martyncurrey.com/arduino-esp8266/

And this FTDI connector (PL2303):



I've just used 3.3v on FTDI module to power ESP, 10k on CH_PD and 1k/2k voltage divider on RX pin. RX/TX to TX/RX connections between FTDI and ESP.

ESP powers correctly and is vendor setted to be an AP. I can correctly connect to it without errors and I see it from WiFi analyzer.

But I can't communicate with it using serial monitor, sometimes I see the port connected and sometimes not and when I try to send a command from Arduino monitor the monitor stop working.

I've checked voltage on TX pin and it's 3.0v, so seems correct. But I've noticed that, after connection of FTDI module to USB and some bliking of TX/RX led it start to blink very weak without stop.

What can be the problem?

I've also tryed ESP module with Arduino(Arduino as FTDI) and serial monitor works correctly.

- Mon Dec 14, 2015 8:27 am #36397 Hi, most FTDI cannot supply the 250mA (peak) required by ESP8266s. Try with an external supply using only TX, RX & Ground.

- Mon Dec 14, 2015 11:48 am #36406 I've tryed to use this FTDI module as power source and Arduino as UART interface and works well. So i suppose that power supply is good.

- Mon Dec 14, 2015 4:24 pm #36424 I can see from here that your USB dongle is Prolific, not FTDI. If that's your exact dongle in the picture.

[some nonsense deleted]

I have to second the suggestion that you add a separate 3.3v supply. There are some vendors who sell very small ams1117-3.3 modules. You could connect one to ground and +5v on the usb dongle.

I have a bunch of these: http://www.aliexpress.com/item/3-feet-A ... 07038.html

They work well on a breadboard, but i found in some cases i still needed to add a capacitor for surges.

Or just use an LM1117T-3.3 and some capacitors.