ESP8266 Community Forum

- Tue May 05, 2015 9:24 am #16566 I have not yet tried it but the RX and TX are also GPIO1 and GPIO3.
so we really have 4 GPIO if you are prepared to lose the UART functionality.

- Tue Jun 23, 2015 1:42 am #21334 I am with the OP.
Sure we can work around the bootloader and fudge things, or since I never intend to boot from serial or SD card with my current units, an alternative bootloader sounds like a great plan.
I vote for network code uploadng..

- Tue Jun 23, 2015 6:22 am #21367 Only GPIO0 is important at boot time.
You can connect the PIR to GPIO2.
Have a look at https://github.com/CosmicMac/ESP8266-trap

- Tue Jun 23, 2015 6:04 pm #21433 The serial bootloader resides on an internal ROM on the ESP. So far, I have not seen any documentation on if or how one would be able to overwrite it. There is a strong possibility, that it's not technically possible to replace the serial bootloader and even if you could, I doubt there would be enough room for a full wifi & IP stack to implement a network bootloader on-chip.
What you can do however is to chain-load a user program from flash to act as secondary bootloader to allow you to flash your ESP via network. However this will not solve your GPIO0/2/15 issues.