How can I get the accelerometer to to be "0" when flat?

Question

Hi, I'm using Midi Designer on the iPhone 4s.

I'd like to create an accelorometer based "modwheel" which is set to 0 (as opposed to 64) when the iPhone is flat.

This means that whilst the iPhone is flat, no controller data is sent (there seems to be a wobble on the iPhone so it outputs 63, 64 when flat but I believe this can be fixed with named ticks), but when tilting the iphone, controller data is output starting at 0 and not at 64.

How can I remap the accelerometer to the desired Midi values?

I can't work it out. the range function doesn't help and display values seem to be for aesthetic purposes only.

Can anyone please advise?

Comments

Start with a new knob.
1) Turn on the accelerometer (X -> .5 -> Any).
2) Change the number of ticks to be an odd number, like 49

Now it will center at 64.

From there we can expand to talk about how to get what you want with more precision.

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Sorry, from your question I'm having trouble separating the description of the problem and the desired behavior. What do you want the device to output? What is it outputting?

Thanks!

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Hmmmm... the question of whether MIDI Designer can go from 0 flat... down to what? Up to what? It's true that Named Ticks might be necessary here, but please explain what you need and we'll see what kind of solution we can find. Thanks

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Ok. iPhone on it's back, screen up, should output MIDI cc with a value of 0.
iPhone on its side, screen facing me (90 degrees rotation from being on its back) should output 127 midi value. Don't care what it says on the screen. This means I can have a "tilt" modwheel effect where I lift the iPhone to create changes in my synth patches (I'd probably map it to cc1).

Currently the iPhone on its back outputs midi value 64. Tilting one way gives values to 127 and the other values to 0. That's not practical in this situation as in order to return the "modwheel" to 0, I'd need to tilt the iPhone.

Hope this makes sense!

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PS thanks for the prompt response, amazing to get support so fast, especially in the holidays, I didn't think there'd be anyone here!!

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Ok, I've worked it out! I hadn't realised how to remap midi values in the named ticks section! I have remapped 64 to 0 and both 0 and 127 to 127, with the corresponding values inbetween. Now if I tilt in either direction I get modwheel values, although these are now at half the resolution. Presumably I could up ticks to 256 to achieve full res?

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Glad to be able to help!

So: you are using a normal CC? A normal CC has only 128 values total (0-127)... while you can repeat values (127 down to 0 and then back up to 127 again) as many times as you want with Named Ticks, you can't get beyond the resolution of the MIDI message type you're working with.

So... I'm not sure I've understood what you're asking in this last comment.

Regarding your center value at 0 (or 64 or whatever): if you "stack" the middle of the Named Ticks range with extra 0 values, it will tend to stick to center better, but you'll notice a visual wobble (but all of those values will be 64 or 0 or whatever MIDI value is defined).