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Domain: epanorama.net
Stories and comments across the archive that link to epanorama.net.
Comments · 66
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Re:All Right!!Most every modern PC already does component out, in the form of an RGB signal. For reference (some of it from what people were doing to run VGA monitors off of the XBox...)
640x480 = 480p
1280x720 = 720p
1920x1080 = 1080i
(I borrowed the 720p and 1080i from some site, so I'm not sure if they will work)
(and I can't remember any others, but there are)
On http://www.epanorama.net/ if you look you can find something like:
(From http://www.epanorama.net/links/videocircuits.html)
Do-it-Yourself VGA ro PPrPb Cable - This circuit is designed to convert 60Hz VGA (480p) from a computer's VGA port and drive progressive-component outputs to an HDTV (or similar display device).
You can also find links for going component to RGB if you want to run an Xbox (or PS2 or DVD player).
FWIW this is a starting reference, don't try something unless you are willing to take a chance that it might screw something up really bad. -
Re:cheap yes, but practical?
>Am I missing something, or is his time worth nothing?
Yes, you are missing something.
Car audio capacitor: 16-20 volts @
Camera flash capacitor: 330 volts @ 120 uF.
Now lets see, using the formula E = 1/2 * U^2 * C, how many joules are in each capacitor.
Car audio capacitor: E = 20 Joules
Flash capacitor: E = 6.534 Joules
Car Cap: $40 or $2 per joule.
Disposable camera: $5 or $0.76 per joule.
Camera caps are far cheaper, and this guy got them for free. -
Re:Build your own
And a more general article on displaying VGA pictures on your TV can be found here. I should've put this in the post I'm replying to, but never mind.
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And some useful references...
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LinksYou might want to try here, especially here and here.
I found this on Google using the search term "computer serial port remote data plans"
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LinksYou might want to try here, especially here and here.
I found this on Google using the search term "computer serial port remote data plans"
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LinksYou might want to try here, especially here and here.
I found this on Google using the search term "computer serial port remote data plans"
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H/W Hacking 101For the last several months I've been wading back into this myself, just for fun, having done alot during and shortly after college 20 years ago, but then drifting away. My suggestions:
1. Suppliers
Digikey absolutely rules. Largest variety of everything electronic. Very easily-navigated site. No minimum order ($5 handling charge if your order is under $25).
Jameco is a good second choice. Especially good for lots of different cheap power supplies.
With Radio Shack, this should be all you need for now.
2. Learning Resources
Someone already pointed you to the various cookbooks. TTL cookbooks are especially good places to start at your level.
A great online resource used to be ePanorama.net, but they're 404ing at the moment, so maybe they're gone for good and they'll be back.
Circuits Archive has lots of simple circuits you can peruse to see how stuff gets done at the lowest level, just like the cookbooks.
3. Advice
Stay away from FPGAs initially. I think you'll find the architecture and associated design process too big a piece to bite off at this point, and not worth the effort.
Focus on TTL and learning what functions are available in various packages (track down an old "TTL Databook" from TI; they don't print them anymore but they're much handier for learning and browsing than online equivalents, which assume youknow what you're looking for). See this for high-level descriptions and this for pdfs of actual datasheets.
When you're ready (which might be immediately) choose a microcontroller family to bone up on and stick with it. It's a huge waste of effort relearning architectures, instruction sets, and development tools for different families. For your purposes, either the PIC (from Microchip), 8051 (Intel et al.), or AVR (Atmel) will do fine (and they're all available from Digikey). I chose the AVR for the following reasons:
a) Wide (enough) range of parts, from 8-pin to 64-pin, 1K ROM to 128K ROM, various arrangments of on-chip peripherals (including A/D).
b) Cheap, from under $2/chip (single-piece) to under $30 for their fanciest.
c) ALL members of the AVR family contain on-chip FLASH ROM for program storage and can be programmed in-system directly via your PC serial port. This makes a HUGE difference (compared to external ROMs or on-chip EPROM) during prototyping.
Some people will suggest the BASIC Stamp from Parallax, which is a fine product which I've played with. My beef with it is it's expensive ($30 or so, I think) and all you really get for the money is a Basic intepreter. I think you'll find assembler for these chips so simple you don't need Basic. You can also get separate free Basic compilers for all of them.
Good luck.
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Ground loopsMost hum problems in audio interconnection come from ground loop. This has nothing to do with cable quality and everything to do with cable topology. If you have a loop of wire, and another wire carrying current runs through the loop, a current will be induced in the loop. This is a ground loop. It's easy to create one when cabling up electronics. The loop can be big; size doesn't matter in this.
Power, grounding, and signals should follow the same tree structure, fanning out from a single power source and grounding point. You may have to violate this rule; if you do, an audio isolation transformer should be placed somewhere in the signal chain to break the loop.
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insert clevvar title here
Take a look at epanorama.net has some neat projects, technical information and links, i suguest you check it out.
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What I know I learned from:I second the practically network site. Especially good are the product reviews. Start here.
On the strength of a Practically Networked review, I had good luck with an SMC Barricade router with 4 ports and a built-in firewall a year ago, but things may have changed a lot since then. It took me only about 15 minutes to install (not counting network setup on the computer) and cost ~$100.
I learned about related topics from
How to set up a network at home: MIT guide with Linux focus.
World of Windows Networking: If Windows networking is screwing up (as it often does), go here.
homePCnetwork forum: Configuration questions answered, mostly by guy who runs the forum.
Technocopia: Overview articles on home networking.
Grant's Closet: Home LAN wiring.
Steve DeRose's guide: CAT5 wiring.
Telecom wiring: links to HOWTO and info articles on wiring.
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Re:Woah, imagine the size of that magnetic fieldAlso, since the power lines must run both ways, coming and going (at least, I believe that's how it works to close the circuit)
Actually, this isn't right. The general scheme is to use an earth return to the power plant. Even if there is a conductor running as a return it shouldn't be carrying any current. You can demonstrate how this works pretty easily with a cheap 2 prong extension cord and a lightbulb.
- Cut the extension cord so that you have a length of cord attached to the end that plugs into the wall. You may discard the end which you'd plug lamps into.
- Cut the wider prong off of the plug end.
- Remove the side of the cord associated with the removed prong.
- Strip a small amount of the insulation from the end of the remaining wire.
- solder this to the threaded part of a lightbulb.
- Plug your modified plug into the wall and touch the base of the bulb to a faucet or other grounded metal object.
- If the bulb doesn't light, turn the plug over and try again.
- BE VERY CAREFUL NOT TO TOUCH THE SHINY METAL PARTS WHEN PLUGGED IN. IT WILL HURT A LOT.
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I was about to... (slightly OT)
...post the following question:
"How do you read the PC joystick port for joysticks with more than four buttons?"
I then gave it a little thought, and realized it was possible to go up to 15 buttons by interpreting the buttons as four bits (value of 0 meaning "no buttons pressed") - but what about other sticks and controllers where things become even more complex? I had always wondered "Does force feedback and similar sticks use MIDI?"...
I decided to do a little searching (via Google), and came across the motherlode of sites to answer my question:
Tomi Engdahl's Joystick Interfacing FAQ
It honestly covers it all - and I thought other
I hope this helps anyone who may have been wondering about all of that - it seems like PC joystick interfacing and programming is still a very interesting, yet obscure art...
Side note: In all fairness, Tomi Engdahl's site is arguably one the best sites on the net for all electronics related information - visit the link if you don't believe me...
Worldcom - Generation Duh! -
I was about to... (slightly OT)
...post the following question:
"How do you read the PC joystick port for joysticks with more than four buttons?"
I then gave it a little thought, and realized it was possible to go up to 15 buttons by interpreting the buttons as four bits (value of 0 meaning "no buttons pressed") - but what about other sticks and controllers where things become even more complex? I had always wondered "Does force feedback and similar sticks use MIDI?"...
I decided to do a little searching (via Google), and came across the motherlode of sites to answer my question:
Tomi Engdahl's Joystick Interfacing FAQ
It honestly covers it all - and I thought other
I hope this helps anyone who may have been wondering about all of that - it seems like PC joystick interfacing and programming is still a very interesting, yet obscure art...
Side note: In all fairness, Tomi Engdahl's site is arguably one the best sites on the net for all electronics related information - visit the link if you don't believe me...
Worldcom - Generation Duh! -
I was about to... (slightly OT)
...post the following question:
"How do you read the PC joystick port for joysticks with more than four buttons?"
I then gave it a little thought, and realized it was possible to go up to 15 buttons by interpreting the buttons as four bits (value of 0 meaning "no buttons pressed") - but what about other sticks and controllers where things become even more complex? I had always wondered "Does force feedback and similar sticks use MIDI?"...
I decided to do a little searching (via Google), and came across the motherlode of sites to answer my question:
Tomi Engdahl's Joystick Interfacing FAQ
It honestly covers it all - and I thought other
I hope this helps anyone who may have been wondering about all of that - it seems like PC joystick interfacing and programming is still a very interesting, yet obscure art...
Side note: In all fairness, Tomi Engdahl's site is arguably one the best sites on the net for all electronics related information - visit the link if you don't believe me...
Worldcom - Generation Duh! -
mix 2 channels the right way (link) + questionhere's a simple schematic for mixing two line level audio signals into one, without degradation. (disclaimer: I am schematic-illiterate and have not tried building one).
Does anyone make a mixer with a tv-style remote? It would be nice to amplify cd player, computer, and tv through my only set of surround speakers, and selectively quiet/silence one channel like when commercials come on.