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it don't respond

PostPosted: Thu Dec 03, 2015 5:15 pm
by Antaras
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 :-( :oops: :evil: :roll:

Re: it don't respond

PostPosted: Thu Dec 03, 2015 5:23 pm
by martinayotte
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.

Re: it don't respond

PostPosted: Thu Dec 03, 2015 6:48 pm
by kolalde
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.