NOTE - IF YOU WANT TO JOIN PLEASE MENTION PIC MICROCONTROLLERS OR TELECOMS IN YOUR REASON - OTHERWISE YOU WILL NOT BE CONSIDERED!

Rat_Ring is an ideas sharing forum for anyone interested in experimenting with low cost telecoms and short range wireless devices generally using the Microchip series of PIC microcontrollers.

RAT stands for Remote Access Terminal, a minimalist communications node using either the telephone network, short range wireless link or GSM to communicate with other RAT nodes or PCs.


RAT_1 is an experimental low cost telecom device using the PIC16F88 micro. A simple line interface allows it to communicate with other RATs or PCs via the phone network, using the V23 modem standard.

To get you started, an EagleCAD home-build version of the RAT_1 is available in the Group's File Archives.

The 40 page tutorial (in English or Spanish) introduces the techniques of tone generation and reception on the PIC and shows how these simple functions can be built into a full repertoire of telecoms routines.

Chapters describe how to power the PIC safely from the line, send and receive DTMF tones, how to use the PIC to generate and receive 1200 baud modem signals.

With RAT_1 you can dial out using DTMF and send outward short messages to a remote RAT or PC sent over the phone line using the V23 modem standard.

The V23 decoder also allows the RAT_1 to decode incoming Caller ID signals and selectively answer telephone calls.

An opto-isolated serial port hooks straight up to your PC and simple serial commands control the RAT_1.

RAT_1 can also be used for remote sensing, with its on board ADC, and Flash ROM, datalogging for example at a remote location and periodically sending the results back to a PC via the phone line.

It is ideal for Home Automation projects switching lights, central heating systems or security systems by activating them from a mobile phone.