[LAU] Two exact same drumpads, different USB ID's

Jeremy Jongepier jeremy at autostatic.com
Sun Mar 3 19:07:05 UTC 2013


On 03/03/2013 04:13 PM, Johannes Kroll wrote:
> I have no idea what chip it uses, but I have played a bit with Atmel
> and ARM chips with built-in USB controllers. The way these work is that
> the controller does the basic USB stuff in hardware, but the higher
> level things, such as the USB class, are determined by the firmware. So
> what you see might be a firmware bug. This sounds likely if that the
> hardware is otherwise identical.
>

Hello Johannes,

Yes, the hardware is identical, PCB's have the same revision, layout 
looks the same, same IC.

> So maybe you could find a way to read out the firmware from the good
> one, and flash it onto the bad one. Unfortunately, most such chips have
> a code read lock bit set, so reading it may be impossible. Anyway, maybe
> you could make photos of the PCB, and also see if you can decipher any
> text on the chip, and post both?

The IC's are blank, there's no text on it. I could make photos, good 
idea. Will do that shortly.

  If we could get these to work, I might
> buy one myself. For that price...:)
>

Afaik these are the cheapest USB controllers available. If you buy them 
in bulk they're even cheaper (as low as $10 a piece!).

> Is the working one otherwise okay? Are the pads pressure sensitive,
> i.e. are notes played with different velocity depending depending on
> how hard you hit it? (Guess not, but it would be cool)

No pressure sensitive pads, just MIDI notes on channel 10. Works quite 
nicely. I'm thinking of taking it apart and using it as  base for a 6 
button footswitch.

Jeremy


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