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S. L. Struthers, R. A. Reichle, V. B. Kuechle, and S. B. Nuorala, Advanced Telemetry Systems, Isanti, MN 55040 USA

Functionality of radio location tags can be enhanced by the addition of microcontrollers. The microcontroller allows changes in the tags operating characteristics by changing the software without changing the hardware. Using a 20-kHz crystal, the PIC16LC54A microcontroller draws only 0.010 mA from a standard 3-Volt lithium cell. This low power and stable time base allows features such as on/off duty cycles to save battery capacity and extend tag life. Multiple inputs and functions are also easily accommodated. Examples of tags monitoring temperature, pressure, and activity/mortality are displayed. Complex tag identification codes are also an option. Since their introduction nearly 3 years ago over 20,000 microcontroller tags have been produced. They have largely replaced the conventional analog circuitry. A large variety of species have been tagged including fish, birds, and terrestrial animals ranging in size from squirrels to elk. More recently, using only the silicon die itself, tags weighing as little as 1.4 grams have been deployed on over 700 smolt salmon. The poster describes tag size, power requirements, programming methods and parameters measured.