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Amiga computer related discussion => Amiga Hardware Issues and discussion => Topic started by: motorollin on May 13, 2006, 06:00:51 PM
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As some of you will know, I use an LCD TV (http://www.amiga.org/gallery/index.php?n=1331) for my Miggy, which displays both the VGA output from my Voodoo and the RGB output from the 15KHz display.
This is handy, but a little bit annoying when I have to use the remote to change from the VGA input to the RGB input every time I change between Voodoo and AGA screenmodes.
I have bought a learning remote, which I will teach the commands to change to the VGA input and the TV input. I will then rip the remote apart and connect it to a parallel relay board. I can then use software on the Amiga to trigger the pushing of each button.
I already use AmigaDOS scripts to run my WHDLoad games, so I can put a command before WHDLoad starts to send the correct command to the relay board to change to the TV input, then once the game has quit it will send another command to change it back to the Voodoo.
Cool huh :-)
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moto
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Sounds like fun, especially with some of the 'One4All' remotes that you can hack their EPROM for new codes and functions :hammer:
Did you ever checkout InfraJoy/InfraRexx (http://main.aminet.net/package.php?package=util/rexx/InfraRexx.lha), an IR interface that connects to the joyport and is controllable by Arexx?
It worked fine on my A1200, but it never learned the IR codes properly on my A4000
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The One4All remotes can't create the codes I need, and it's cheaper to get a universal remote than to get a chip programmer to rewrite the One4All's ROM ;-)
That project you linked to, was it the one CU Amiga gave away on a magazine cover? They had the PCB sellotaped to the front, and you had to send away for the components. I built it once, but never got it working.
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moto
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Hi,
Sounds like a fun project. I'm not sure exactly how you will do it, but can't you do this just with logic gates, and leave out the relays? I think it should be simpler, smaller, and use less power.
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I built a working IR interface from the magazine many years ago complete with the stickers :-D
If Arexx can do this it could be the better option as it opens up other control idea's and possibilities as well
:idea: but for now, its Sunday afternoon so I'll have a :pint:
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Oliver wrote:
Sounds like a fun project. I'm not sure exactly how you will do it, but can't you do this just with logic gates, and leave out the relays? I think it should be simpler, smaller, and use less power.
If you can tell me how, then I'll do it :-) I know very little about parallel ports so I wouldn't know where to start.
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moto
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I haven't used parallel ports for much before, but I think they're not overly complicated.
I think your current plan is to switch some control signals for the remote via relays, right? So probably this could be done using transistors instead. I've only used relays when I've needed to switch fairly large currents, or AC currents. You shouldn't normally need to use relays for digital control signals. I think relay designs are generally bigger and more expensive than transistor designs, and can create additional electrical noise.
Maybe I've misunderstood your idea. :-?
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You understand correctly :-) The relay board will connect to the parallel port. The Amiga will issue a command to the parallel port which closes relay x. Relay x will close, completing a circuit which will short across the contacts for button y on the remote control, in effect "pushing" that button.
If you think this could be done better with transistors and can let me know how, then I will try. Otherwise, I would rather not experiment and risk damaging my parallel port!
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moto
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Hi,
I would guess you could do the same design that you were thinking of, but use transmission gates instead of relays. Do a search for 'transmission gate'. There are other ways to tackle it, but I think this would match your original idea very closely.
You could have a look at this chip (http://www.fairchildsemi.com/ds/CD/CD4066BC.pdf). It has 4 transmission gates built in. There should be a number of implementations, each of a '4066' designation. The switch resistance is ~80 Ohms. I think most relays will give much lower resistance than this, though.
I seem to recall there are also solid state relays available now (I've only used the electromechanical types). I think internally, they are similar to photoconductors or MOS transistors. These should be smaller, less noisy, and maybe have multi packaged designs, and presumably low activation currents.
Otherwise, you could have a look inside the remote control, and see what kind of signal is required internally. Then, design the transistors to affect the signals as required. This might be more of a hassle for you though.
edit- I haven't looked at this very closely, so take all the usual precautions.
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motorollin wrote:
The One4All remotes can't create the codes I need, and it's cheaper to get a universal remote than to get a chip programmer to rewrite the One4All's ROM ;-)
You don't need a chip programmer, just a homemade serial cable that connects to a header that's hidden inside the battery compartment
More info on the JP1 website (http://www.hifi-remote.com/jp1/)
That project you linked to, was it the one CU Amiga gave away on a magazine cover
Yup that's the one, IIRC Eyetech used to sell them too. Although I guess it depends if you'd rather hog a joyport or parallel port as to what method you eventually end up using.
There's a post by Stedy (http://groups.yahoo.com/group/Amiga-Hacks/message/1950?viscount=100) on the Amiga Hacks Yahoo group with some details of possible problems and fixes for the InfraJoy, I guess he's been too busy with the Amy'05 to test them out.
I stumbled across something else on aminet that might be of interest to you,
TURD (http://main.aminet.net/package.php?package=hard/misc/turd_020.lha) ..The Ultimate Relay Driver, supports parallel port relay cards and also has ARexx support.
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I did look at TURD on Aminet, but I want something which can be driven with CLI commands, not a GUI or ARexx. Once the relay board has arrived I will probably be looking for advice on writing a small C programme to control the parallel port.
There is a Unix command to drive parallel relay boards, and if I understand correctly it sends an 8 bit string to the port which turns the 8 data lines on or off, which is then translated by the relay board to turn the 8 relays on or off.
I suppose this would be quite simple to achieve with the Amiga, but I have no idea where to start.
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moto