Some time ago I got bored of my remote's short range and low battery life, and thus often having to replace batteries (4 remotes, what a pain) so I decided to take a cool old universal remote with a screen and mod it for my specific purpose. The idea was to first test the concept with my Arduino Uno and then buy a Nano or other smaller version.
Further research gave me the idea to use my laptop, or my phone! The latter seemed very convenient so I went that way. I built an IR blaster that connects as standard stereo 3-pole headphones. I could have added a second (inverse - polarity) IR diode but I skipped that just for looks
https://photos-4.dropbox.com/t/2/AABkuNcyjiF_l0Mnd8kGn2F5uGusvLj0iZAPzTYOI1IP3g/12/248604589/jpeg/32x32/3/_/1/2/P1250567.JPG/CK3PxXYgASACIAMoAQ/61DrHPswjgNkJIYwmjcFaLqO33cPuljsV_QtVf2jyCM?size=1024x768And a close-up:
https://photos-6.dropbox.com/t/2/AACsgfVL1jKhjDB1ut5-xKkIDpXblwbkZtkxff0-3ar9VA/12/248604589/jpeg/32x32/3/_/1/2/P1250566.JPG/CK3PxXYgASACIAMoAQ/8riC1hUZmde1BRaZJslgdD_samd42w-xa0S5Ldlbdj8?size=1024x768All pure scrap parts. Anyhow, I also managed to find an application for this exact purpose, namely the IRDroid project...
Website:
http://www.irdroid.com/Play store:
https://play.google.com/store/apps/details?id=com.microcontrollerbg.irdroidHowever it can only work with the preset remotes and codes, even though they claim you can add your own. It also has an incredible lack of documentation - thus becoming a useless app.
They claim that you can record the signals from your own remote (via WinLIRC) and then use the file generated as a template within the app. But this is hard maybe impossible to achieve.
WinLIRC:
http://winlirc.sourceforge.net/I did attempt to do it however - downloaded WinLIRC, set up the hardware and started recording. The program even confirmed codes were recorded but something was wrong (I did manage to learn a great deal through this process - infrared is complicated technology and hacking a remote incredibly complex to understand, so I will not explain further).
For anyone interested in attempting this, the IR transmitter only takes a banana jack with at least 2 poles (you wire up the GND and Audio from the jack to GND and V+ on the emitter diode). The receiver (if used with WinLIRC microphone plugin - simplest) takes another 2-pole or more 3.5mm audio jack (which you connect to your computer's microphone port) and you wire up the GND to the pin that sends the data. An IR receiver looks something like this:
https://www.sparkfun.com/products/10266They all use 5 volts and thus have a GND, +5V and Data pin. I connected the power pins to my Arduino and the 3rd pin to the computer.
It's a simple and cheap project, could also be useful as you can easily come up with many uses for a custom remote. WinLIRC is designed for controlling your PC and with your PC via infrared - home automation etc. All the parts I used were salvaged (except for the Arduino sadly) but they are cheap anyway.
But the reason I came here is that I seek help. I lack the skills to create such an Android program. There are tutorials on how to make a program but the examples are meant for phones with built-in IR transceivers and not for external IR blasters. I have no idea how to achieve this - of course the phone needs to send audio signals to headphone port but as I said IR technology is goes deeper then it would seem and I can barely make an Android calculator with Xamarin. I am also working on another project so I sadly have no time.
I could provide some assistance and input if anybody is looking for a not-so-big project to work on and learn something new. If not then I hope this post was helpful and informative for some of the readers!
Note: Some computers can interface directly with IR diodes as they have header pins on the motherboard for that specific purpose (I do suggest adding a long wire tho as IR receivers require an unobstructed view of the emitter). Consult your motherboard documentation if you want to know if you have those.