DIY arduino capacitive touch midi-controller
This project is new midi-controller but with capacitive pushbuttons. This makes the project much cheaper. Using this method, velocity sensitive buttons can be created and aftertouch can be sensed.
Look for capSenseMidiController.ino
To use your arduino as a midi-controller, you have to upload the right code and change it to accommodate your needs (like amount of buttons etc.). Then you need to create a virtual midi-device with Loop-midi. That's because music software doesn't recognise your arduino but they do recognise the virtual device. Last you need to use Hairless midi to change the incoming signal from your arduino to midi-data and send that date to your virtual device. Now if you select the virtual device in your software, you'll be able to use it as your homemade midi-controller.
(To save: "right-click"-->"save as")
I don't take any credit for the hairless-midiserial converter and loopmidi. Each of these two links will bring you to the coresponding page of the author in question.