Propeller "get together", fun times
Dennis Ferron
Posts: 480
A friend of mine who's a real electronics geek had an afternoon free last weekend, so I brought my suitcase computer project over there so I could show him what the Propeller could do. (Plus, I hoped he would have some of the hard-to-find resistor values I needed to complete the video out circuit!) I brought everything I could possibly need with me except the demo board schematic, because I thought we would get it from the internet there. So of course we had computer problems and couldn't get on the internet. After two hours of frustration we finally got that fixed. Then it turned out he didn't have the right resistor values for the video out either, but we hit upon the idea of using 1K and 2K 15 turn trimmer pots to adjust to the exact ohms we wanted. And we didn't have an RCA jack, so I had to cut a female RCA end off a cable. Couldn't find a PS/2 jack, so we had to take one off an old motherboard.
After all the trouble we went to, when it came to actually getting the TV output, everything went smoothly. It's ironic because during this whole time, we were also watching a Mythbusters marathon, and at one point in the show Adam was talking about how it scares him if everything goes perfectly because that means there's going to be some huge disaster at the end. On the other hand, he said, if you have lots of little stupid problems all the way, that's enough to appease the gremlin gods and hopefully in the end your project will work.
Pretty much everything we tried after that worked fine. I tried out the graphics demos, and I even got to play with Mike Green's Propeller OS. Later I made some ascii-art in the edit program from Mike's OS. Those are what the screenshots are.
You can see a closeup of my suitcase computer in one of the pictures. It doesn't look like much yet, but pretty soon it will have a hard drive and trackball. When I write the code for accessing the IDE hard drive from the Propeller, I'll make it publicly available. I'll be using an 8255 (i/o chip) to talk to the IDE interface. I'm trying to stick as much to the demo board schematic as I can, so I'll use pins 0 to 7 for the data lines to the 8255. I'll still have to steal the pins that control the VGA video on the demo board in order have enough pins to do the addressing and control of the 8255, so for those of you who have demo boards instead of the PropStick you'll have to plug jumper wires into the VGA connector's pin holes and run them back to the breadboard.
In another picture, it shows me kneeling behind the computer. (My friend declined to be photographed.) There is another suitcase on the floor in that picture (my friend's building one too), and that is what these suitcases look like when they are closed.
I don't have a name for my suitcase computer project! What should I call it?
After all the trouble we went to, when it came to actually getting the TV output, everything went smoothly. It's ironic because during this whole time, we were also watching a Mythbusters marathon, and at one point in the show Adam was talking about how it scares him if everything goes perfectly because that means there's going to be some huge disaster at the end. On the other hand, he said, if you have lots of little stupid problems all the way, that's enough to appease the gremlin gods and hopefully in the end your project will work.
Pretty much everything we tried after that worked fine. I tried out the graphics demos, and I even got to play with Mike Green's Propeller OS. Later I made some ascii-art in the edit program from Mike's OS. Those are what the screenshots are.
You can see a closeup of my suitcase computer in one of the pictures. It doesn't look like much yet, but pretty soon it will have a hard drive and trackball. When I write the code for accessing the IDE hard drive from the Propeller, I'll make it publicly available. I'll be using an 8255 (i/o chip) to talk to the IDE interface. I'm trying to stick as much to the demo board schematic as I can, so I'll use pins 0 to 7 for the data lines to the 8255. I'll still have to steal the pins that control the VGA video on the demo board in order have enough pins to do the addressing and control of the 8255, so for those of you who have demo boards instead of the PropStick you'll have to plug jumper wires into the VGA connector's pin holes and run them back to the breadboard.
In another picture, it shows me kneeling behind the computer. (My friend declined to be photographed.) There is another suitcase on the floor in that picture (my friend's building one too), and that is what these suitcases look like when they are closed.
I don't have a name for my suitcase computer project! What should I call it?
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Comments
Those little problems are nothing while prototyping. You can almost count on something of that sort happening.
As for a name? I don't know. Why don't you call it the Compu-Case or something. (lol)
(btw) Nice ASCII Bugs, Bunnies and Knights you got there.
--Andrew Arsenault
I know! I'll call it, The Osbourne I. Oh, wait a minute. That name's already been used.
By the way, you might not be able to see it in the picture, but I had a big mistake in my wiring. Instead of running the five volt line from my 7805 to the PropStick's VIN, I ran it to the 3.3 volt power pin for the Propeller! I've been running my poor Propeller chip on five volts ever since last Saturday! Luckily the chip seems to have not suffered any damage from this. In fact, it never even got warm. I've since fixed the wiring.
We could have classes on advanced topics, like ASM, and signal processing, and share ideas. I think it would be stimulating for everyone, and a lot of fun.
Could many of you come out for two days? We could feed you breakfast and lunch, but you'd need your own lodging arrangements and transportation.
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Chip Gracey
Parallax, Inc.
I would certainly love to go if I could. I might be able to get one of my professors interested in this and then we could both go. Give me a few months and I might also have some robots to bring with me, as well as my portable Propeller computer.
Is it possible that you could set up some kind of simultaneous webcast of the event for those who live too far away to attend in person? Kind of like the MSDN event broadcasts that Microsoft does. Usually when I saved the day at work because I knew some trick nobody else knew how to do, I had learned it from watching an MSDN event. A presenter would be like, "Hey! There's this cool trick you can do in Visual Studio [noparse][[/noparse]...]" and the very next day I'd run into a real-world situation where I needed that. Technology events and get-togethers are a very valuable way to spend your time.
I would attend, just need a good lead time, so I could make travel/hotel arrangements. Not a far drive from Washington.
Charlie
I would love to attend so long as it was around 3-6 months from now. I was at the original Propeller seminar in February, and would love to see what everyone has been doing since the release in person. An ASM class sounds great.
John
www.johnsrobotics.com
-Marty
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Martin Hebel
Personal Links with plenty of BASIC Stamp info
StampPlot - Graphical Data Acquisition and Control
AppBee - XBee ZigBee / IEEE 802.15.4 Adapters & Devices
'Sounds like fun! No sooner than mid-March would be optimum for me. I encountered snow in the Siskiyous on my drive back in February. This being an el Nino winter, there's likely to be more this time 'round. Not a huge deal, except for the salt that California uses on their highways. My poor car!
-Phil
You can count me in!
The Propeller unveiling this last February was a great experience!
Cheers,
Peter (pjv)
Not to reanimate a dead horse, but I had a realization the other day about getting decent spectral purity out of the current PLL's. I noticed that the video has no problem placing the aural subcarrier at whatever the base frequency is plus 4.5MHz, with no audible noise. The aural subcarrier is FM'd at 4.5MHz +/- 50KHz in one COG, then utilized by another COG which XORs it at the base broadcast frequency (50MHz+) using the video circuitry. To make a long story short, you can pick a base frequency that is big (90% where you want to be), but has only a few signficant bits to keep the jitter pattern simple and digestible by the PLL. Then, FM a secondary signal at some much lower frequency in another COG and·mix them with the video circuit. You will get a mirror at base-minus-secondary, but the one of interest will be much better than trying to do it all at once.
So, we'll see you at the Propeller bash!
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Chip Gracey
Parallax, Inc.
any thoughts of a web based live shot for us north of the border (or those outside of the continent?)?
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Steve
"Inside each and every one of us is our one, true authentic swing. Something we was born with. Something that's ours and ours alone. Something that can't be learned... something that's got to be remembered."
Chip Gracey
Parallax, Inc.
Hmmm, guess that means BOTH then
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Cheers,
Simon
I guess.....I would have to just watch.....maybe next time.
James L
BTW: any seminars going north of the border? Or close to the border?
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Steve
"Inside each and every one of us is our one, true authentic swing. Something we was born with. Something that's ours and ours alone. Something that can't be learned... something that's got to be remembered."
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OS-X: because making Unix user-friendly was easier than debugging Windows
links:
My band's website
Our album on the iTunes Music Store
Mike
For VGA Presentation, this would most likely be done over Netmeeting and a combination of setting up a call-in bridge. (<--Please everyone mute their microphones unless they wish to speak)
I'm not sure about video I think this would take up too much bandwidth. If a server was setup to stream the video in real time, you would run into bottle necking issues due to high volume.
We might be able to provide a temporary directory where people could d/l video from the Propeller get-together at a later time however.
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Beau Schwabe
IC Layout Engineer
Parallax, Inc.
That sounds like a great idea. Please drop me an e-mail when you are ready for a small propeller class get togeather !
Rob7
Tell me when, where, & how, and I'll tell you what,
I'll bee there!
Sounds greate!!!!!!
count me in
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