Scripting Setup and the Camera + Serial Port Drivers

[Tom Bottiglieri]

Wow, I never even thought to daisy chain processors using the serial port.

*achieves the "aha!" moment*

[Venkatesh]

These multiprocessor systems sound very familar, a la 2003. In 2003, the Basic Stamp 2SX which we used was ill-suited to working with complex feedback systems and autonomous mode, so hundreds of various kludges were put together to all increased speed and advanced features.

A few notes of advice with regard to multiprocessor configurations.

First, debugging a system with one microcontroller is hard. Debugging one with two processors is 4 times as hard. Three is 9 times as hard and so on and on. Unless you have very very good reasons for using them, do not bother. You need a lot more electrical and electronic skill than is the norm to make such things work.

If you are interfacing a Basic Stamp to the PIC in the IFI blackbox, the BS has 2 ports which can be used for serial communication very easily, the two data pins of the programming port. These can be linked to the serial port of PIC and Mr.Watson's serial driver (and PBASIC serin/serout) can be used for data transfer. Remember, the Stamp is not capable of working at high serial baud rates!

If you want to go way overboard in terms of power (ie you have at least ten electronics and programming experts on the team), you could look into the line of Rabbit microcontrollers. They feature Ethernet connectivity and are very easy to use, if you can convince the manufacturers to donate the programming software ($395). I once used a Rabbit, 2002 FIRST controller, a relay, and a car battery to make a toaster with a webserver on board. Truly useful tools, those Rabbits.

If you add a second processor to just service interrupts, an older PIC16 should be able to do just fine, with the serial code from Mr.Watson.

But if you want to use some more sophisticated electronics to add features, one more option is available. Connect the IFI controller and the aux microcontroller to 74LS138 decoder chips. Then connect the output lines of the decoders to 8 AND gates (8 gates per decoder line). This system allows you to build a rudimentary bus between the processors, on which peripherals (sensors, etc) can be connected. We used this arrangement in 2003 (with tristate gates rather than AND gates) and it worked great.

And lastly, Good luck!

[CJO]

Thank you,

The third option, this would be using another PIC 16 or 18?