Mobo Attiny programing

mwalimu

Is there a general library for reprogramming the Attiny chips on the Mobo? I have a few ideas for using the Attiny chips, but no idea on how they handle the one wire routines that the Stamp uses to communicate.

Phil Pilgrim (PhiPi)

Attached is the source code for the GPIO3 firmware that comes preinstalled on the MoBoStamp-pe's AVR coprocessors. Hopefully you wil find it useful for your needs. Be forewarned, though, that I cannot provde any further assistance with it, either here in the forum or privately, so please don't ask. You are on your own from this point on.

Good luck with your project!
-Phil

mwalimu

Thanks, Phil.

I pretty much realized I'm my own here, in which case I have a complaint. What is the point of having two coprocessors if you can't do anything with them? I think at the very least Parallax should put out some documentation on the One Wire routine it uses to communicate with the ATtiny chips. And how about the source code for the Taos Line Reader.

Phil Pilgrim (PhiPi)

The OWIN and OWOUT stuff, including timing info, is nicely documented in the PBASIC manual. In fact, it was all I needed in order to write the AVR code.

The original idea behind the AVR programs provided with the MoBo and various daughterboards was that they provide black-box functionality that is easy to load and whose functioning is well-documented and fully-supported. In this way the AVRs are treated simply as logic extensions to the BS2pe chip, but whose behavior can be changed. In fact, the original reason they were put there is that, being less expensive than dedicated ADC chips, they were the cheapest way to provide analog inputs on the MoBo. Of course, being very capable micros in their own right, their mission in life grew from there.

Opening the source does carry the risk that it, too, would have to be supported, adding yet another processor family for Parallax's tech support to deal with. Hence my rather strongly-worded caveat about not providing support for the source code. Nonetheless, your question coincided with Parallax's recent push for more openness, so I decided it was time to provide the source. If this goes well, I may do the same with the TSL1401 driver and have already expressed this to Parallax. No promises, though!

-Phil

Ken Gracey

It's the case that our support staff doesn't program AVRs and can't help too much. It's not that we don't want to help, we simply can't!

But you'll find several AVRs in our own designs. Those are specified and designed-in by the other side of our office, Engineering.

If it helps our customers then we support releasing any AVR code, without support. The only problem with it is that we usually say "we support everything we sell". That's why I prefer the use of the forums for such releases - upon request instead of posted on the product page.

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Ken Gracey
Parallax Inc.

Follow me at http://twitter.com/ParallaxKen for some insider news.

mwalimu

I guess I'll have to learn to speak AVR. Would that you had used a PSoC or a Pic, I know those already.

Phil Pilgrim (PhiPi)

Both the PIC and PSoC and were considered, in fact. I, too, had PIC experience, but no AVR experience at all when I made the selection. The PIC was eliminated because it couldn't have been programmed via the BS2pe as easily as the AVR. The PSoC was quite intriguing, but it's kind of like a thousand-bladed Swiss army knife: I just knew that once I had figured out one of the blades, there'd be another poised to stab me in the back. And there just wasn't time climb that learning curve. As it turns out, the ATTINY13 is just about the perfect chip for this app: it's small and cheap; but with its 9.6MHz clock, it's an able performer. To a veteran PIC programmer, the architecture seemed a bit quirky at first, but it was easy to get used to.

-Phil

mwalimu

"The PSoC was quite intriguing, but it's kind of like a thousand-bladed Swiss army knife: I just knew that once I had figured out one of the blades, there'd be another poised to stab me in the back."

But think of all the things you could do with those blades. I wrote a FORTH for one of those little 8 pin wonders. It's a pretty cool chip.

I get why you used the ATtiny chips, they are effective and cheap.