GA144 one pin oscillator again

I don't think there has been an debate about whether a crystal oscillator is "possible" on the GA144. I have not yet seen any proof or even reasonable evidence that a robust, reliable software based, crystal oscillator has been demonstrated on the GA144. I will take a look at the video you describe, but if it is anything like the other app notes from GA it will be largely hand waving and leave the bulk of the work to the viewer. Demonstrating a reliable oscillator is very different from producing an app note that shows one working in the lab.

What type of resonator is demonstrated? What frequency? One of the problems encountered before was how to start a high Q oscillator at a higher frequency, I believe 10 MHz. There is not enough resolution in a 700 MIPS instruction stream to tune to the crystal rate to get it going.

Rick

I think I'm going to make some popcorn. This should be entertaining.

-jim

I will not go into it whether that debate has taken place.

I'm talking about the debate whether even an experimental oscillator using only a crystal, a single pin and no further components is possible using the GA144. A demonstration is relevant to that discussion.

Yes, this is a demonstration only, not giving enough information to build the thing yourself. It will irk you. The source code is shown, on a barely readable video screen, in the unfathomable colorforth language. Still *I* think it is an interesting video.

I take exception to this. It depends on the crystal frequency. I intend to experiment with a 32kHz clock crystal.

Groetjes Albert

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Without commenting on the technical feasibility, the last time there was a discussion on this I looked at the white paper from the processor company and it seemed to be nearly all smoke and mirrors. What little content there was could have been generated by a fresh college grad (one who got a low GPA) wandering into the lab and doing some hurried work at the last minute.

Either they have such a weak product that they feel they need the smoke and mirrors, or they have such little regard for their customers that they do not feel that decent applications support is worth paying for, or their top management is incompetent at selecting competent engineering staff, or money is so tight that they can't put together the competent staff they know they need.

None of these circumstances make me feel that designing in their processor would be a good risk.

You may be able to make that work at 32kHz. To verify that what you do will actually work correctly in the long run you not only need to be good at analog circuitry and at software, but you'll need the cooperation of the manufacturer -- and given their capabilities in that direction, I don't think you'll ever get there.

Oh, I certainly agree with you there. Green Arrays consists of senior citizens with very little in the direction of marketing potential. I'm purely interested in the R&D aspects. (Members of) the Dutch Forth chapter are experimenting to get a decent development environment for the chip. We do get some cooperation from Green Arrays.

Groetjes Albert

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What exactly is "a decent development environment"? Is the eval board lacking in some way? Is the software not good enough?

I am planning to build (not yet committed 100%) a beagle board daughter card using a GA144. I want to design it so it can be a daughter card but it can also be a stand alone card or use the other Beagle board daughter cards. Would a board like this be of any use? I do plan to add oscillators rather than try to get the GA144 to drive a crystal using only one pin.

Rick

I can't pin-point it exactly, but the operational definition would be that it allows someone to switch from a Microchip environment to a GA144 environment with a comparable amount of effort to switch to an ARM. Now the colorforth hurdle is very steep. An absolute requirement from my part would be the possibility to use a code management system, source that can be communicated as ascii file via a mail attachment.

What is a beagle board?

The target application for GA144 is in the realm of a 3 by 3 cm solar cell powered MP3 player. A prototype for such a beast can't be made with the current development environment. (The wow would be the smallness and lack of even a backup battery, light enough to bungle from your head phone. That would be lost with the current development board.) A board accomodating that more or less would be nice.

Probably wise, but you're moving away from ultra-low power then.

Groetjes Albert

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So you want ascii files. What else is wrong with the development system?

Beagle Board (BB) is an open source project using the TI high end ARM processors on a small, low cost development platform. There are several other similar projects, but from what I see the BB is the most popular. They have a version which is a square board, around 3 inches on a side (10 cm) and a newer version is the Beaglebone (3.4" x 2.15" or 86 mm x 55 mm) which skips the video output and is more useful for embedded apps. Both have Ethernet and USB as well as an expansion bus. They are very similar to the raspberryPi boards which attracted so much attention a month or two ago. The difference is you can buy the BB.

My goal is to leverage the popularity of the BB (as much as a GA144 board can) as well as leverage some of the peripherals. So this board will be form factor and I/O pin compatible with the Beaglebone most likely. They call the BB daughter boards "cape" boards, a throwback to the Arduino shield boards. So some BB users would buy this board to add I/O capabilities to the BB, To use the GA144 more fully they can write forth code for it. Others may be interested in using this board standalone as a much lower power replacement for the BB itself. Using it standalone the standard BB daughter boards can be supported.

It is highly unlikely that any eval board you find will be form factor compatible with your project. Schmartboards makes an adapter board for the GA144 which you might be able to squeeze into your project size.

I looked into this and found any number of low power commercial oscillators. I've been away from the project for awhile (saving the US) and don't recall any companies, but they are out there. Since GA never explained how to actually build a single pin oscillator I don't see how you can say their solution would be any lower power than any other. That's the big problem with GA, to this day, nearly a year after announcing their chips could be bought, they still don't have any real info on how to use them on the hardware level.

Rick

If you remember the posts about experimental one pin oscillator some time ago, here's an excerpt from Chuck Moore's blog

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Jeff Fox has died of a heart attack. He was a wonderful character and a long-time Forth enthusiast. His website ultratechnology.com is a fount of information about Forth and Forth chips. Jeff was a good friend and supported my chips with money and effort. I'll miss him.

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That's 2011.

There is a thread in the comp.lang.forth group about using the GA144 in "killer apps". I would like to hear any comments folks might have.

Rick