Simple Wifi RS232 Modem

The ‘Simple’ Wifi Modem it’s a device to connect a computer with an RS232 serial port to a telnet BBS. It does not use an analog phone line but internet through a wifi connection. Behaves like a Hayes dial-up modem, and it is designed and built for old computers; i use it with my first computer ever (still working!): a Sinclair Zx Spectrum. My idea was to create a device with the same look and feel of a real modem: a lot of big, flashing, red LEDs and only a few SMD components.

Main characteristics:
Emulation of a Hayes modem
DB25 serial connector (optional external port)
Uses 5v micro USB cable port for power
LEDs for status, as in old modems
Hardware flow control (partial implementation)