Microcontroller Circuit

The potentiometer portion of a mixed-signal, digitally programmable potentiometer adds variability to an analog circuit, and its digital controls provide programmability. You can use a digital potentiometer in two ways in an analog circuit. You can use it as a two-terminal variable resistance, or rheostat, or as a three-terminal resistive divider. Although both ways bring variability to the analog circuit, the three-terminal implementation usually brings other important characteristics as well. For example, a programmable voltage reference has two implementations...

This is the hardware and source code for an Atmel ATmega8 / MX-614 based UI only TNC. The intent was to provide inexpensive basic TNC functionality for APRS related packet activities. We also have the flexibility to modify the operations of the TNC by modifying the source code to add features or modify existing functions...

This was my second Nixie clock project. I wanted something a little smaller / cheaper / simpler then my rather large B-7971 clock. I will post the design for that one of these days. I was trying to simplify everything. And basically wound up with a one chip solution, ... the micro itself does just about everything...