Thread: Selecting a microcontroller
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Unread 20-05-2008, 02:45
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AKA: Jason Brett
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Re: Selecting a microcontroller
Well, I'm a bit biased here because most of my chip-level work with uC's has been with the PIC 16F series of chips, and for a couple bucks each (they'll even ship you a couple demos for free if you ask nicely) the PIC16F627A would be a good place to start (yes, you can get more advanced PICs for about the same price... but I've worked with the 627A a lot, and it just springs to mind first.)

There is a free C compiler available, PICC Lite, although I don't know if it will work on a Mac. PIC Basic Pro is also a very luxurious language for compiling to the PIC... it has all sorts of easy to use routines, but does cost a couple hundred dollars. The programmers can be whipped up on a breadboard if you want to use a PC parallel connection, but you can also buy them either assembled or as kits for less than $100. And I think you can even get a USB programmer for less than $100.

We've been using them for years with my engineering 11 students and while I found the 16F84A tended to be even more resistant to damage (one even kept working after a student put it in backwards, shorting it out so I burned my finger on it when I touched it!), the 16f627a has been pretty good, too, and is dirt cheap to boot. I don't mind throwing one or two out when students toast them. (But don't tell the student's that, or they'll stop believing my "be more careful" theatrics.) Besides, with the internal oscillator you don't need a crystal, or anything other than a +5V and GND to get your chip up and running. It makes for very simple circuit boards! You will be stressing it a bit if you put all 20mA draws on the same port and turn them all on and leave them on for a long time, but it should be able to handle it.... and if you are worried just put three on PortA and three on PortB.

An added benefit is that you should find lots of MPLab and PIC machine level expertise on this forum as PIC chips have powered the FRC control system since... well... since longer than I know of... and continue to run the VEX robotics platform.

Jason