This project is using the ESP-07 module to drive an RS232 interface via a MAX232. Pretty simple, but it should allow devices with a serial interface (like a projector) to be accessed via the network.

Programming happens via the same RS232 port, there are small reset and program buttons. I also added the option whether you want a device or host serial interface (crossover of the RX/TX lines).

All GPIOs and the ADC are broken out to regular 2.54mm pin headers. Power supply is 5-12V via a barrel jack.

The board is designed to use only one layer, so it should be possible to etch this at home (if you can manage the TSSOP footprint).