Making MIDI Bass Pedals

[Austin73]

Hi everyone,

I know this is a bit off topic but your the only forum I'm on. Was thinking (as I always do!) Would it be possible to make my own Midi Bass pedals. I have just put in for a Yamaha Electone on freecycle and hopefully if I get it was hoping to rip the pedals out and see what I can do with them.

Was thinking how hard would it be to buy a small USB Keyboard or midi controller say 26 note and get the pedals to control it?

I haven't got  a keyboard at hand to open to see if I could do such a thing. I did notice another member did something similar so just wondered if anybody had any advice or input.

I fancy doing this project but I'm not desperate enough to pay £250 for a kenton one.

Cheers in advance as always

Austin

[RickL]

I've done it several times on both MIDI and non-MIDI keyboards. The thing you have to watch out for is that keyboards typically use a matrix to determine which key you've pressed. Imagine a checkerboard numbered 1 to 6 along one edge and a to z along the other. When you press the lowest key (call it C1) you connect 1 and a, C#1 is 2 and a, D1 is 3 and a ... on up to F1. F#1  is 1 and b, G is 2 and b ... and so on.

Normally each key has a diode between the switch and the numbered contact. You can wire the switches on the bass pedals up without the diodes as long as you don't try to play two notes that share the same number at the same time (i.e. C1 and F#1 or C1 and C2).

You're better to wire the pedals with the diodes but figuring out where to put them and what orientation can be awkward.

Keyboards that are velocity sensitive add a whole other set of problems since each key has two sets of contacts (IIRC), one N/C and one N/O. The brain of the keyboard times from when one contact opens to when the other closes to determine the velocity. Single switch pedals can be made to work with velocity sensitive keyboards (effectively giving maximum velocity each time you hit a pedal) but I can't remember how I did it. I think it involved more diodes on each switch on the pedals.

The simplest and cheapest way, if you just want to trigger  single MIDI notes at a set velocity is to buy the cheapest non-velocity sensitive keyboard you can find (old portable home keyboards with small keys are usually cheap) and simply parallel the switch contacts on the keys to the corresponing contacts on the pedals. I've even made pedal boards using simple push button switches mounted on a piece of board.

[Austin73]

Hey Rick,

Cheers for the reply, I think it was you that gave me the idea actually. Maybe I should look out for an old Yamaha PSR keyboard that has midi out . I thought the usb keyboard might be a bit tricky as I'm sure its all surface mount too. Not sure I have actually been accepted to tak ethe organ but if I do I will continue this thread about the problems and ideas etc so please feel free to jump in with any advice.

Thanks

Aus

[Meanderthal]

 OMG! Rick! That's a great idea! I just happen to have the foot pedals from an old Thomas organ... was going to use a resistor network for CV, but WOW! MIDI! Thanks!

[R.G.]

Great minds run in the same ruts! 

I just bought a footpedal section from an old electric organ this past December. The scheme I had was to scan it with a PIC and have the PIC send out MIDI. There are several places with "MIDI out" code on the net.

Good work!!

[Austin73]

Thanks for coming over chaps.

RG as always you make the complicated things sound easy. I'll probably end up trying to make a mechanical switching system like the old typewriter with a midi keyboard at the end.

I've just been over to MIDI projects and its mind blowing. I might post on there to see if we can get some help.

You got to check out the pic of the floorboard with 8 expression pedals!

Cheers anyway

Aus

[Austin73]

Just thought I'd let you know I found quite a bit of info on http://www.ucapps.de/

You'll have to search as I can't work out how to post the forum on here.

Apparently we need at least 2 modules a CORE unit and a Digital input, there is a place in the US that makes the boards for about $10 so maybe this could be a good project to jump in together.

Also if you get chance look around the site, you think Dragonfly's paint is cool I didn't realise DIY could be so cool!

Cheers as always

Aus

[Austin73]

Try this link

http://www.midibox.org/forum/index.php/topic,10460.0.html

Hope this helps

Aus