Turn Your iPhone Into A Hardware MIDI Controller

iphone-midi-controllerHMB Tec has released HMB-TEC Midi Controller (App Store link), described as a “fully functional MIDI out terminal” for the iPhone.

The $4.99 app works with a hacked headphone cable to turn an iPhone into a hardware MIDI controller.


Would you like to remotely control your MIDI devices, like Midi keyboard, Drummachine or Synthesizer with the iPhone to send control sequences, select tools, select Effects …?

This iP / iPT-app, in conjunction with some easy to build DIY hardware, makes it possible. The need for the connection hardware you can build a few simple steps and a few electronic components themselves. You can also select all ready built and tested in order HMB | TEC Web Store.

See technical details below.

This looks like a very interesting hack – but the combination of Googlish instructions and cable hacking mean that this project is not for the timid.  Let’s hope other iPhone music app developers take this idea and build on it.

How does the HMB-TEC Midi Controller work?

Connect the hardware to your iP/iPT 4-pin headphone socket and operate one of the 12 function keys. The operation mode selected by default is “feature”. You can send pre-defined midi sequence with one touch. You can change this default setup, just press the “Contence” button and press the function button to change. The same also applies to the button labels, where you previously choose “Title” for readers to modify the desired function key label.

Selecting the function mode “transmit” You can make direct entries of midi sequences and send it via midi to your own devices. In both modes you can embed the typical Midi commands. The following commands are available:

  • “a” = MIDI channel select 1. .16, e.g. “a2” is selecting midi channel no. 2 (out of 16 normally available)
  • “b” = command to send pitch bend change , e.g. “b100 0”
  • “c” = control change command, e.g. “c7 127” to set the volume to maximum
  • “n” = plays notes, for example, “n20”, or play multiple notes “n20 n30 n36”
  • “o” switch off = note, for example “o20” or “o21 o22 o100”
  • “p” = Patch Change, e.g. “p2”
  • “r” = Midi reset

iphone-midiThe commands you can modify to suit your requirements, or overwrite it. The changes, of course, remain even after you switch off your iP/iPT. So it is very easy to create your personal MIDI Pad fully self configured and remotely control your external MIDI drumbox or your MIDI keyboard. In the pre-defined key settings, you will find further relevant examples. By pressing the “Help” it displays a help page, e.g with a circuit diagram how to build the midi hardware option. In the current version two help pages are available, they change at every access.


To run this app you need an additional hardware, you can create yourself as a little DIY project or refer HMBTEC web store were you can purchase ready for use hardware. The midi-terminal operates unidirectionally, i.e. it can only send data – not received! For damage caused by the operation of DIY hardware-created the author assumes no responsibility. Always make sure that no voltage from outside the device (IP / IP) is fed!

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