ESP8266 Community Forum

- Fri May 15, 2015 6:45 am #17456 Hey guys, i just connected the board to my arduino, i tried it with both my diecimilla and UNO and when i plug it in, the serial monitor on the arduino stays blank, my wiring is as follows, tried all baud rates and all of them are blank, i get no scrolling either


GND > 0v
Vcc > pwr supply 3.3v, it keeps drawing between 70-90 mA
URXD > Arduino RX, i have swapped this with TX but same result
UTXD > Arduino TX
CH_PD > to 3.3 on pwr supply
GPIO0, 3.3V on pwr supply
GPIO2, 3.3 on pwr supply
GPIO15, 0v

Any help would be appreciated. Thanks

- Sun May 17, 2015 4:58 am #17629 hello,

you just need:

rx and tx (esp rx must use level shifter if arduino runs on 5v) to arduino tx and rx
vcc to 3.3v
gnd to ground
ch_pd to 3.3v
gpio15 to gnd via 1k resistor

for fw update, additionally gpio0 needs to be pulled to gnd while booting up.

regards

- Sun May 17, 2015 9:10 am #17652 If the reason for connecting it to the Arduino is to talk to it using the Arduino IDE serial monitor, you have to ensure the Arduino itself stays quiet, so before connecting the ESP, compile and upload an empty sketch.
Then Connect ESP Rx to Arduino Rx and ESP Tx to Arduino Tx. Try different baud rates; not all ESPs come shipped with 9600 firmware.

And don´t forget level shifter on the Rx line, or you risk frying the ESP.

Good luck!

- Mon May 18, 2015 6:23 pm #17794 Thanks guys, i think i already fried it though, i was using a voltage divider on rx and tx, but i think that i needed to take out the voltage divider coming into RX in the arduino as that is an output of the ESP which is already at 3.3 V.