On Mon, 20 Feb 2006, Wouter van Ooijen wrote:

> Recently there was a discussion that ended in a number of very
> convoluted ways to enter a program into a PIC. I think I have the idea
> about the ultimate convoluted bootloader: the non-electrical contacts
> bootloader. It uses temperature cycling to enter the data! The PIC uses
> its (temperature dependent) watchdog timeout to measure the temperature.
> Reset it at >100C and it enters the bootloader. 90..110 is the idle
> temperature, a temperature excursion above 120C is a 1, an excursion
> below 80C is a 0. I guess 160 millibaud (= one bit per minute) is easily
> done this way.

And the tool used to affect the heating is a magnifying glass, using the 
sun as power source ;-)

Peter
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