Python to send Midi commands to iPad via USB

[mikprog at gmail.com]

On Thursday, January 24, 2013 10:44:47 AM UTC, Chris Angelico wrote:
[..]
> 
> Are you able to hook into ALSA? I've had reasonable success driving a
> 
> USB-MIDI cable using ALSA. See if you can do it with the inbuilt
> 
> 'pmidi' app first:
> 
> 
> 
> $ pmidi -p 128:0 No.19.mid
> 
> 
> 
> (that uses port 128:0 which is a TiMidity-provided one)
> 
> 
> 
> If that works, you can then look for Python ALSA bindings, which I
> 
> believe are available on PyPI.
> 

Thanks for your help Chris!
forgive my ignorance, but I am not sure what you mean.
I've installed pmidi and what I get is:

~$ pmidi -p 128:0 No.19.mid
Could not open file No.19.mid

Doesn't that mean that the iPad is not seen?

where:
~$ lsusb 
Bus 001 Device 001: ID 1d6b:0002 Linux Foundation 2.0 root hub
Bus 002 Device 001: ID 1d6b:0002 Linux Foundation 2.0 root hub
Bus 003 Device 001: ID 1d6b:0001 Linux Foundation 1.1 root hub
Bus 004 Device 001: ID 1d6b:0001 Linux Foundation 1.1 root hub
Bus 005 Device 001: ID 1d6b:0001 Linux Foundation 1.1 root hub
Bus 006 Device 001: ID 1d6b:0001 Linux Foundation 1.1 root hub
Bus 007 Device 001: ID 1d6b:0001 Linux Foundation 1.1 root hub
Bus 008 Device 001: ID 1d6b:0001 Linux Foundation 1.1 root hub
Bus 003 Device 002: ID 0a5c:4500 Broadcom Corp. BCM2046B1 USB 2.0 Hub (part of BCM2046 Bluetooth)
Bus 005 Device 002: ID 0a5c:5800 Broadcom Corp. BCM5880 Secure Applications Processor
Bus 003 Device 003: ID 413c:8157 Dell Computer Corp. Integrated Keyboard
Bus 003 Device 004: ID 413c:8158 Dell Computer Corp. Integrated Touchpad / Trackstick
Bus 006 Device 002: ID 192f:0416 Avago Technologies, Pte. 
Bus 002 Device 003: ID 05ac:12a4 Apple, Inc. 


Essentially the reason to use the iPad is because we have to make a demo where with our hardware we send midi commands and the iPad has a very good DJ application that can be used with a USB midi controller.
So I wish to connect our hardware to a Raspberry Pi (or similar) via BLE and then the board (Raspberry Pi) to the iPad through USB cable.

I think the weak point is communication from the Raspberry Pi (or PC) to the iPad via USB. I could actually remove that if I find a decent Linux/Python application that acts as a DJ deck.

I am having a look at pygame.midi as well, but I am not sure how to link that with a USB cable.

mik