I had this idea while sitting in trafic the other day...
Two Hondas, one in front of me, and one to the side were both playing their god awefull music as loud and with as much bass as they possibly could.... so everyone could enojy it. Nice thoughfull lads that they were... Now if I could only turn them off.
I was thinking that since all the aftermarket stereos have IR receivers (for the accessory remotes), maybe it would be possible to get a bunch of different codes (pulse rates) for the source/off signals and make a remote that I could use from my car. To turn them off if I sought fit to do so.
I know this is going to take a large IR signal... Any ideas on if this is possible?
Maybe a remote with a least 5 IR LEDS that all have a little more then the recommended mA going to them?
If this would work, I relaize that it would be more effective turning the night since remotes seams to work crappy in the sunlight.
remotes always put more current trough the leds then normal, because they're pulsed at 38Khz...
some remotes put over half an amp trough them.
A pic can be programmed to emmit diffirent codes, but i don't think you can reach the stereo in another car, you'll need to be dangerously close for the receiver to see you...
And you'll never catch a honda anyway :lol: (just kiddin)
At night my stupid tv remote can bounce off a mirror and reach across the house to turn the tv on or off.
From my seat to the guy next to me, or in the next car is 1/2 that distance.
I'm not sure how much effect that a tinted backglass would have.
Anyway, what I'm figuring is maybe a BIG led or set of them, or some other source of pulsing IR light.... I think a lamp would be too slow to get up to 38k so i'm probally limited to LEDs.
I can pull the codes easy enough from other remotes...
Is a remote with 10 LEDs going to be 10x more effective then a remote with 1 ?
As I see it your first problem is finding out what remote codes the stereos use - bearing in mind every stereo probably uses a different coding system. You need to get a system working at very short range first, for all the makes and models you hope to 'attack'. Then you can start worrying about increasing the range!.
your idea reminds me of another project I wanted to build but never got around to it.
it was one of those 'back of a circuits magazine' kits, the universal car alarm tester ... just a device that spewed arm/disarm/panic codes out across the frequencies used by car alarms ... I guess some think it was a burglery tool, I just thought it'd be hillarious to set off a big cross-section of alarms all at once.
anyway ... as for getting the IR into the other guys car:
heres a 3.6amp (nominal?) IR led array, i'm sure pulsing it with a pic you could push even more current... should be able to cut through just about any window tint or glass in the way
**broken link removed**
I wonder how many permutations there are in 'standard' IR commands ... maybe a pic could be programmed to just blast them out at high speed, hoping you hit the right code or any code, that turns off the system or has other amusing effects.
I wonder how many permutations there are in 'standard' IR commands ... maybe a pic could be programmed to just blast them out at high speed, hoping you hit the right code or any code, that turns off the system or has other amusing effects.
There are huge differences between IR codes, I've no experience with in-car ones, but TV's, VCR's etc. use vastly different coding systems. The most popular is the Philips RC5 system.
You can't send them at high speed because they are a slow signal, each command might take a couple of 100mS.
Actually you might be surpised what you could learn if you started playing with something like this. I don't think you would need much power running through the LEDs at all, as many films and plastics become transperant at the frequencies in the IR band. Similarly, using a broad beam width you could easily get the IR detector in the sound system head unit.
As Nigel has stated, the hardest part would be in finding the right codes that the car stereos use. This could probably be fixed by a quick trip to your local car audio shop armed with a PALM or similar pocket PC type device which has an IR port. Many of them have software which can perform the same function as a self learning remote control. Ask for a demo of all the units and suck up the codes
The idea is not as crazy as it sounds and while it wouldn't have much in the way of commercial application, it could make a fun project for someone who wanted to play and learn how IR remotes work.