I am building a RDF transmitter for a high altitude balloon. I plan to use a PIC to control when it transmits (timing), to generate a MCW ID, to switch power levels, etc. During the early phase of the flight, the transmitter will not be active, but the PIC has to keep track of time in order to turn on the transmitter about two hours after the launch.
I'm worried about the PIC hanging up/resetting at the extreme cold of near space. The temperature gets to -60degC, which is 20degC below the -40degC temp range specified by Microchip. While extremely cold, all the PIC needs to do is keep the timing going. As the balloon descends, things warm up above 0degC, so only the timing function has to keep running.
What are the pitfalls? A separate temperature-based watchdog (i.e. reset the PIC when the temperature rises)?
I'm worried about the PIC hanging up/resetting at the extreme cold of near space. The temperature gets to -60degC, which is 20degC below the -40degC temp range specified by Microchip. While extremely cold, all the PIC needs to do is keep the timing going. As the balloon descends, things warm up above 0degC, so only the timing function has to keep running.
What are the pitfalls? A separate temperature-based watchdog (i.e. reset the PIC when the temperature rises)?