Remote Applications Terminal
The RAT or Remote Applications Terminal is an expandable, low cost, simple microcontroller device based on the popular flash series of PIC microcontrollers including the 16F84A, 16F628 and the 16F877. The device is fitted with a simple telephone network interface which allows it to communicate with other devices, such as other RATs or PCs over the telephone network, using the newly emerging V23 standard for fixed line SMS messages.
Four variants of the basic design are proposed:
The designs are freely distributed to all interested parties, and firmware is on a shareware basis. This is fundamental to the concept of providing a low cost platform for application development and home experimentation.
The RAT is programmed with a small kernel of firmware known as the RatCore which allows the communications including DTMF generation and reception and V23 modem tone generation and decoding.
The RAT3/4 can be programmed to call a PC server on a regular basis, for example once per month, to download the latest version of firmware, or as a means of retrieving a regular text bulletin.
One of the principle applications of the RAT is as a remote datalogger. Data can be stored in E2 memory and then uploaded to the PC Platform at regular intervals or when the data capacity is reached