You can buy a complete modem from [my shop](http://unsigned.io/shop), or you can build one yourself pretty easily. Take a look at the documentation in the [MicroModem](https://github.com/markqvist/MicroModem) repository for information and getting started guides!
When the modem is running in KISS mode, there's really not much more to it than connecting the modem to a computer, opening whatever program you want to use with it, and off you go.
You can also configure the modem in direct serial framing mode. If using direct serial framing, the firmware uses time-sensitive input, which means that it will buffer serial data as it comes in, and when it has received no data for a few milliseconds, it will start sending whatever it has received.
If you're manually typing things to the modem from a terminal, you should therefore set your serial terminal program to not send data for every keystroke, but only on new-line, or pressing send or whatever. You can also compile the firmware for KISS mode serial connection, if you have a host program using KISS. If you are using MicroModemGP with [Reticulum](https://github.com/markqvist/Reticulum), use KISS.
The project has been implemented in your normal C with makefile style, and uses AVR Libc. The firmware is compatible with Arduino-based products, although it was not written in the Arduino IDE.
Visit [my site](http://unsigned.io) for questions, comments and other details.
