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Dec 31, 2006, 05:17 AM
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Copterbrain lives!

In a record 2 days of soldering and debugging, copterbrain is alive. Its bootloader is programming its flash and sending back debugging info.

Currently the servo inputs are sharing the programming pins because the programming pins are the only ones which can generate interrupts.

There actually is 1 more pin capable of generating interrupts, should the need for a collective pitch servo arise.

Copterbrain is our second use of a double edged clock for the parallel port communication, allowing much faster programming.

One trick to get copterbrain to communicate was to delay between toggling an output pin and listening to in input pin. Toggling output pins caused transients on the input pins.

The next step is to benchmark math routines. Probably going to be a fiasco.

Before flight:
Drop from the current, overclocked 48Mhz to the rated 40Mhz.
Move programming pins away from servo pins.
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Jan 02, 2007, 02:58 AM
Watts is where its at!
racerxky's Avatar
This looks cool!

On the old 386 class hardware there wasn't enough floating point horsepower to do real time trig for games. So instead they did lookup tables which gives you blindingly fast trig ops. at the expenses of some space. Since servos have a low output resolution anyway (1k steps?) the full 32 bit result is going to be seriously rounded off on output anyway. Might be worth considering if you have the space to make the trade off.

Good Luck!

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