ESP8266 Community Forum

- Mon Dec 15, 2014 12:39 pm #4858

> Also never ever supply 3.3V to GPIO2. I burnt two of them by doing so.

Why that? I thought GPIO ports are 3V3 save.

During startup GPIO2 is used as output UART Tx1 . 3v3 will damage the pin when it outputs low.

My ESP8266 dev board https://www.tindie.com/products/Ba0sh1/ ... d-adapter/

- Tue Dec 16, 2014 3:42 am #4905 Thanks for reporting the GPIO2 issue. I will put a 220 Ohm resistor between GPIO2 and the microcontroller to protect the pin.

- Tue Dec 23, 2014 6:28 pm #5569 I have this esp8266-07 with the same pin out 16 pins castellated like the esp-12. It will not serial program.
An esp-03 device will program with the same connections see below.
CH_P/D RST RX TX GPIO 0.
CH_P/D normally pulled high....but pulled low for programming
RST pulled high

Since the esp-07 has other pins like GPIO 15 do any of these other pins need to be pulled high or low for programming?
Solved issue was gpio-15 needs to be pulled down

- Wed Dec 24, 2014 3:37 pm #5635

...
An esp-03 device will program with the same connections see below.
...
Solved issue was gpio-15 needs to be pulled down

As far as I know, the pulldown on GPIO-15 is also required on ESP-03...