jumpjack
Member level 1
griffin sound to ir converter
I think it could be interesting to be able to program VCR recordings remotely by sending it an SMS. Although it sunds strange, it IS feasible and even cheap: an old Symbian s60 phone with IrDA capabilities costs around 50$, and software do exist which performs remote controls emulation; it's just a matter to write a "wrapper" which converts SMS to "keystrokes" sent to the remote emulatore software.
But I have a problem: IrDA port canNOT sample remote controls data! The only way to be able to control home devices is hoping to find ready-made "codecs" for "Psiloc Total IR Remote" or "Novii Remote" suitable for those devices.
OR another solution is possible...
**broken link removed** successfully "hacked" an IPOD turning it into an unversal remote control!
The key points are:
- using pocketPC IR port (maybe it's not a standard IrDA?!?) to sample remote control;
- "play" the recorded sample through the headset port, but rather than connecting it to a headset, connecting it to a special device: an audio-to-IR converter!
Another guy found out that a standard audio card can be used to sample remote controls data.
Somewhere else I read that a TSOP 1138 (or 1138 or 1738) IR receiver can be used to decode RC data, which consist of a 38 KHz carrier "pulsed" to emulate bits by presence/absence of the carrier itself. I think this would result in a signal a lot more "slow" than 38 KHz. This should means it can be sampled by a standard audio card, resulting in something like a square wave. This should hence allow recording IR remote data into a standard WAV file.
Now, the difficult part: how to reproduce these data and send them to TV or VCR?!?
Griffin Technologies created this strange device:
**broken link removed**
It appears as a headphone jack with 2 IR led. Nothing can't be found on internet about internal schematics. And here it comes where your help is needed!
I'd like to recreate this small device,as this would allow ANY device capable of audio-out to act as a remote control.
A lot of work has been done by**broken link removed**: he tried to "reverse engineer" the device without even opening it.
Ina few words, he guesses that it's made up of two IR leds because each one is connected to one of the stereo channel; each channel can reproduce up to 20 KHz signal, but if you prperly chose the phase of the two signals, you should be able to produce an actual 40 KHz signal!
The guy also guesses that, to raise device range, a "special waveform" is sent to the device before the actual code, in such a way that a capacitor in the device is loaded, and then it releases irs charge to increase available current to drive the leds.
Now, the question:
do you think this is correct? Is anybody able to build the Griffin device basing on these suppositions, and tell us if it actually DOES the job, i.e. control the VCR?
I think it could be interesting to be able to program VCR recordings remotely by sending it an SMS. Although it sunds strange, it IS feasible and even cheap: an old Symbian s60 phone with IrDA capabilities costs around 50$, and software do exist which performs remote controls emulation; it's just a matter to write a "wrapper" which converts SMS to "keystrokes" sent to the remote emulatore software.
But I have a problem: IrDA port canNOT sample remote controls data! The only way to be able to control home devices is hoping to find ready-made "codecs" for "Psiloc Total IR Remote" or "Novii Remote" suitable for those devices.
OR another solution is possible...
**broken link removed** successfully "hacked" an IPOD turning it into an unversal remote control!
The key points are:
- using pocketPC IR port (maybe it's not a standard IrDA?!?) to sample remote control;
- "play" the recorded sample through the headset port, but rather than connecting it to a headset, connecting it to a special device: an audio-to-IR converter!
Another guy found out that a standard audio card can be used to sample remote controls data.
Somewhere else I read that a TSOP 1138 (or 1138 or 1738) IR receiver can be used to decode RC data, which consist of a 38 KHz carrier "pulsed" to emulate bits by presence/absence of the carrier itself. I think this would result in a signal a lot more "slow" than 38 KHz. This should means it can be sampled by a standard audio card, resulting in something like a square wave. This should hence allow recording IR remote data into a standard WAV file.
Now, the difficult part: how to reproduce these data and send them to TV or VCR?!?
Griffin Technologies created this strange device:
**broken link removed**
It appears as a headphone jack with 2 IR led. Nothing can't be found on internet about internal schematics. And here it comes where your help is needed!
I'd like to recreate this small device,as this would allow ANY device capable of audio-out to act as a remote control.
A lot of work has been done by**broken link removed**: he tried to "reverse engineer" the device without even opening it.
Ina few words, he guesses that it's made up of two IR leds because each one is connected to one of the stereo channel; each channel can reproduce up to 20 KHz signal, but if you prperly chose the phase of the two signals, you should be able to produce an actual 40 KHz signal!
The guy also guesses that, to raise device range, a "special waveform" is sent to the device before the actual code, in such a way that a capacitor in the device is loaded, and then it releases irs charge to increase available current to drive the leds.
Now, the question:
do you think this is correct? Is anybody able to build the Griffin device basing on these suppositions, and tell us if it actually DOES the job, i.e. control the VCR?
