MIDI Bass Pedal Prog Change

[Robrolley]

There is nothing like a pressing need/deadline to get you to finish a stalled project which was started some months back. So time to finish the Bass Pedals.
My question is before I commit to drilling the metal work and wiring up

Can I do this ?

I have 13 Bass pedals 1 common signal all normally open contacts.
I have 6 momentary foot swithches and a ready supply of singe LEDS.

I originally had thought of using the push buttons for octave up down and return to normal ,but as I will be using soft synths and routing via PC that will be able to do that as part of the patch so that gives me more for different patches.

What I would like to do is connect the pedals with no matrix so that is 13
So with 24 I/O I can use 13 for pedals, 5 for Patch Change switches, 5 for a single (10-15mA) Led above each patch switch to indicate which patch s active and 1 remaining switch with no Led.

The most usefull thing I can do with that is a "Midi Note Off" so if I play a bum note with a long tail I can silence it.

My confusion comes from which pins to drive the LEDS
Is it only 0-7 ?

If that is the case the I'll need to remap MIDI notes for the keys?
I'd welcome any suggestions and a config file as I need to get this done within a couple of weeks

And do I need a buffer to drive the LED's or is only one on at once at 15mA
ok ?

What value do I put where Patch Change as I will again remapp via PC but a good start would be 00 01 02 03 04,

Thanks
Rob up a mountain in Wales

[John]

Hi Rob,

Did you check out this thread? It will help a lot with the LED stuff:

http://forum.highlyliquid.com/showthread.php?t=378

The MIDI CPU requires LEDs to be matrixed, so you can either use 6 control terminals (1 x 5 matrix) or, with a little extra work, 5 control terminals (2 x 3).

One-at-a-time at 15mA would not be a problem, but it's a bad practice to rely on software configuration to keep you within electrical specifications. The case to consider is the current draw with all LEDs "on" at once.

If you have a 2 x 3 LED matrix and reduce the current draw down to 8mA per LED, that would work OK without buffering.

Setting up the other control terminals for the notes & PC messages you want will be no trouble at all. If you can make a list of control terminals 0-23 and your proposed function for each, I'll help you formulate the configuration sysex.

[Robrolley]

Hi John
Thanks for your reply.
Ok I think I have it ...For LED's
Use terminal pin 8 and above for common and the lower pins for the individual elements of Matrix.

OK a quick re_calc ..I cant fit 5 Patches and an all notes off without external logic gates.
4 will patch pbuttons be just fine.
Here is my connection scheme

Pin Function Description
0 Patch 1 LED Illuminates when Patch 1 PB pressed momentarily Patch change message sent
1 Patch 2 LED Illuminates when Patch 2 PB pressed momentarily Patch change message sent
2 Patch 3 LED Illuminates when Patch 3 PB pressed momentarily Patch change message sent
3 Patch 4 LED Illuminates when Patch 4 PB pressed momentarily Patch change message sent
4 Patch PB 1 Normally open Push button
5 Patch PB 2 Normally open Push button
6 Patch PB 3 Normally open Push button
7 Patch PB 4 Normally open Push button
8 LED Common 1
9 Un used
10 Note off PB Normall open Push button send notes off message
11 Pedal Board C Note 36
12 Pedal Board C# Note 37
13 Pedal Board D Note 38
14 Pedal Board D# Note 39
15 Pedal Board E Note 40
16 Pedal Board F Note 41
17 Pedal Board F# Note 42
18 Pedal Board G Note 43
19 Pedal Board G# Note 44
20 Pedal Board A Note 45
21 Pedal Board Bb Note 46
22 Pedal Board B Note 47
23 Pedal Board C Note 48



I'm not wedded to it so if it makes it easier to code I'm happy to move pins around
Also a 2 *2 Matrix is a pssibillity using the unused pin ?

Whatever you propose will be fine. I have just finished the woodwork and metal work and will be hopefully soldering at the weekend.

[John]

Hi Rob, looks good. Yes, you can use the unused control terminal for another LED common output, if you want to add up to 4 more LEDs.

Here's the config code for what you have listed. I'm assuming a common-cathode LED matrix. Also note that the interpretation of the "all notes off" message is left up to the receiving module and results may vary.

Layer 0:

F0 00 01 5D 04 01
00

// CT 0-3: LED Matrix Data
00 00 2B 00 00 00
01 00 2B 00 00 00
02 00 2B 00 00 00
03 00 2B 00 00 00

// CT 4-7: Program Change 0-3
04 00 50 00 00 00
04 01 7F 00 00 00
05 00 50 00 01 00
05 01 7F 00 00 00
06 00 50 00 02 00
06 01 7F 00 00 00
07 00 50 00 03 00
07 01 7F 00 00 00

// CT 8: LED Common Cathode, Bit Indication
// Using Register 11h for LED states
08 00 2A 00 02 11

// CT 9 Disabled
09 00 7F 00 00 00
09 01 7F 00 00 00

// CT 10: All notes off (CC 123, 7Bh)
0A 00 4C 00 7B 7F
0A 01 7F 00 00 00

// CT 11-23: Notes 36-48 (24h - 30h)
0B 00 44 00 24 7F
0B 01 44 00 24 00
0C 00 45 00 25 7F
0C 01 45 00 25 00
0D 00 46 00 26 7F
0D 01 46 00 26 00
0E 00 47 00 27 7F
0E 01 47 00 27 00
0F 00 48 00 28 7F
0F 01 48 00 28 00
10 00 49 00 29 7F
10 01 49 00 29 00
11 00 4A 00 2A 7F
11 01 4A 00 2A 00
12 00 4B 00 2B 7F
12 01 4B 00 2B 00
13 00 4C 00 2C 7F
13 01 4C 00 2C 00
14 00 4D 00 2D 7F
14 01 4D 00 2D 00
15 00 4E 00 2E 7F
15 01 4E 00 2E 00
16 00 4F 00 2F 7F
16 01 4F 00 2F 00
17 00 50 00 30 7F
17 01 50 00 30 00

F7

Layer 1 Config

F0 00 01 5D 04 01
01

// CT 4-7: Set corresponding LED control bits in register 11h
04 00 74 00 11 01
04 01 7F 00 00 00
05 00 74 00 11 02
05 01 7F 00 00 00
06 00 74 00 11 04
06 01 7F 00 00 00
07 00 74 00 11 08
07 01 7F 00 00 00

F7

[Robrolley]

Hi John
Thanks for the SYS Ex
I had to change the key assignment from

0B 00 44 00 24 7F
0B 01 44 00 24 00
0B 00 45 00 25 7F
0B 01 45 00 25 00
0B 00 46 00 26 7F
0B 01 46 00 26 00
0B 00 47 00 27 7F

To
0B 00 44 00 24 7F
0B 01 44 00 24 00
0C 00 44 00 25 7F
0C 01 44 00 25 00
0D 00 44 00 26 7F
0D 01 44 00 26 00
0E 00 44 00 27 7F
etc..

But other than that it now works great.
I am using a Virtual Synth Taurus Bass Pedal. The Patch push buttons change the patches. Sooperb

So thanks again and have a great Christmas. Happy to put up some pics of it if you think there is any interest in seeing it.

Rob

[Jim McDougall]

Yes please post pictures !

[Robrolley]

Hopefully you can see what the final product looks like
Just have to apply some labels

Rob

[Robrolley]

The finished product

[John]

Rob, thanks for finding the error in the sysex config that I provided. I have updated the sysex in the original post to avoid confusing other readers.

And thanks for posting the project photos. The build looks really nice. I will have to include this in a blog post.

Happy new year.