I'm using a home automation controller with several 3.5mm IR outputs.  These IR outputs are typically cables connected to IR emitters that you place on the front of your equipment so the controller can send IR commands to the different devices.

However, some devices have an 3.5mm IR input which means I can connect a 3.5mm cable from my controller directly to my device and the IR commands are sent over the wire and do not require an emitter.

Can any of the Flirc models be modified (?) to directly connect a 3.5mm cable to it?  I'm just trying to avoid sticking an emitter on the Flirc.

 

You would need to remove the IR receiver from the board. But it probably won't work that way, because the receiver on Flirc's board is a demodulating one. It takes an IR signal modulated with carrier frequency of around 38 kHz and demodulates it into serial binary data stream. Your IR emitters are probably fed using a modulated signal so if you connected it directly to the Flirc's microprocessor then the firmware wouldn't know what to do with the modulated signal.

You would need to demodulate the signal first but it's be probably hard to get a separate IR demodulator (without the optics part) which would be electrically compatible with the one Flirc uses.

Also I wouldn't recommend placing an IR emitter directly on the Flirc as its receiver is really sensitive and the signal could be too strong. This may cause poor performance.

Thanks very much for the information.

It sounds like I'll need an IR emitter instead of a 3.5mm cable but I'll lower the output sensitivity on my automation controller.

Also, do you know if there any certain remote control protocols that are faster than others?  I'd like to optimize the response from Flirc to be as fast as possible.  (my home automation system can also output any IR protocol, etc)

 

I would stick with NEC2 or NECx2. Maybe they're not the fastest but it's well defined and Flirc doesn't have any problems with them. Also there's really no advantage from a faster protocol because Flirc key repeat rate is not affected by the amount of frames sent over a specified time span. It detects repeating frames and tells the operating system that the key is being held. It's up to the system to define the keyboard repetition rate and delay.