I want to implement serial communication into one of my projects, but I'm hesitant to use a serial cable due them them being exceedingly hard to find nowadays. I found an old converter and took it apart to see whats inside it, and to my surprise, they were all components I already own (basically). Just a pic microcontroller (a really old one which I don't own), and a level converter (not the max232 which I have). Are there any tutorials that include code that would explain how to build one of these from scratch?
I use this part in a lot of my products. It creates a virtual com port (essentially this chip is what is inside a converter cable but this way your product still has a normal USB connector).
The above is just one example. I'm sure there are other similar parts out there.
FTDI's DB9-USB modules provide a USB-serial adapter in the same form factor as a conventional DB9 connector, allowing you to place either in the final product in order to meet requirements.