This is a KISS Radiomodem with Dorji DRA818V as VHF TRX. All credits to Mark Qvist since most of this software is from MicroAPRS. I did some changes of how the PTT pin is contrled so there is no need for a transistor to control the PTT and I also changed preamble to 1500. The reason for the preamble change is that the T/R swithcing is quite slow on the radio module.
I am going to add bit banging UART, so its possible to configure the radio module from the microcontroller and I am also going to change the uC from ATmega328 to ATmega328p. there is also going to be a USB-LVTTL converter IC, but this is for the final design.