Software based CLIP decoder
Simple ald low-cost CLIP (Calling Line Identification Presentation) decoder, which
decodes caller number coded with V.23 protocol (FSK modulation), and shows it on LCD display.
Device is based on simple AVR '2313 microcontroller and is an example, how to decode caller ID in a software manner.
Here's short overview of V.23 coding:
Block diagram of CLIP decoder:
CLIP decoder features
||V.23 (FSK modulation)
||Analogue phone line
CLIP decoder firmware (6.66kB)
Source code (written in C) shows how to decode CLIP signal
coded with V.23 FSK protocol using only simple AVR microcontroller and simple analog front.
Schematic diagram (PDF) (17.36kB)
Project developed in 2004.