ESP8266 Community Forum

- Sun Jan 18, 2015 3:37 am #7577 To normal operation, you must pullup GPIO0 with 10kOhm resistor (pulldown if you want to upload firmware).
Your power suply looks to be OK.
If you want to connect with 5V Arduino get proper logic level converter (mosfet based) not fiddle with resistors.

- Sun Jan 18, 2015 4:35 am #7582 But i need GPIOs to control 2 relays through 2 transistors... How can i control them if i put a resistor on gpio0?

About level shifter...when the esp8266 boots it correcrly speaks with Arduino, so are you sure that the voltage divider on RX could prevent the module from boot?

- Sun Jan 18, 2015 4:52 am #7584 Try to pullup GPIO0 for a test.

You may get two more GPIO from your board if you use my hack: viewtopic.php?f=13&t=1216
But you must use modified firmware in this case.

GPIO0 at boot times outputs 2MHz clock signal so yours relay go nuts.
Also GPIO2 at boot time outputs some UART0 TXD signals.

GPIO9 and GPIO10 normally are used for Quad SPI for flash memory, but when you flash in DIO mode ESP8266 is not using them.

- Sun Jan 18, 2015 6:09 am #7593 Thanks for your usefull reply!
Anyway I found this guy that successfull uses GPIO0 and GPIO2 to control 2 relays: https://scargill.wordpress.com/2015/01/ ... t-success/

EDIT: i just noticed that the guy is using a solid state relay... maybe i can't use tradition relays with GPIO0 and GPIO2 as you said...
I think that i will just connect the Arduino and forget those GPIOs, because your hack seems to complicated to me