ESP8266 Community Forum

- Thu Dec 03, 2015 5:15 pm #35603 hello im little bit confused !!!
if any one can help me pls !!


USB 2.0 to TTL RS232

ESP8266 ESP-12


* 1) case i connect my esp with arduino UNO:

ESP / ARDUINO
GND / GND
VCC / 3,3V
TXD / TX ( 1 )
RXD / RX ( 0 )

* 2) case i connect my esp with arduino UNO thru usb

ESP ARDUINO USB
GND / GND / GND
VCC / ------ / VCC ( with 2 in serial resistor 1 + 2 = 3 K ohm 5v to 3,3..v)
TDX / TX / ------
RDX / RX / -----

*3) direct in pc with usb

ESP USB
GND/ GND
VCC / VCC ( with 3k ohm resistor )
RX / RX
TX / TX

in first and the second (*1,*2) case i dont take nothing from the ESP in arduino console

1.gif

in third (*3) case i connecting with pc ( win7 ) and i run the putty

2.gif

i choose the serial, my com port with 9600 or 115200 but again i dont take nothing in console

what other can i make .. ??
is about to go crazy

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- Thu Dec 03, 2015 5:23 pm #35606 Are you saying that you use 3K resistor in serie with VCC to make your 3.3V power supply ?
Since the ESP can use as much as 200mA, with your "technique" it ends up with few millivolts instead of 3.3V.
Simply check it with a voltmeter
Use proper external supply along with a 3.3V regulator, such as AMS1117.
Also, be carefull with RX not receving a 5V logic level, you need level translator or voltage divider.

- Thu Dec 03, 2015 6:48 pm #35607 are you also saying you connected RX to RX and TX to TX? I'd think you need to swap those, if I'm following you, and check the voltage on all output pins from the usb->ttl device, like Martin said.