Midi inside guitar project

[Doug Theriault]

Hello-

I'm rebuilding a guitar I have routed out for a controller using the Highly Liquid CPU. It will have 13 potentiometers, 1 Membrane potentiometer and 8 switches.

Once I get the CPU programmed with Sysex, then I'll assemble it all and take pictures.

I'm a little confused with how to program CC#s. These are the numbers of the controllers I would like to program into the CPU.

Potentiometers:

CC #s

98,99,100,101,102,103,104,105,106,107,108,109,110, 111

Switches:

CC#s

20,21,22,23,24,25,26,27

Can the switches be momentary and when you push them it goes from 0 to 127, then when you press it again it returns to zero? or do I need latching switches?

The Pots should be 10k correct?

Thanks! :)

Doug Theriault

[John]

Hi Doug,

Hello-

I'm rebuilding a guitar I have routed out for a controller using the Highly Liquid CPU. It will have 13 potentiometers, 1 Membrane potentiometer and 8 switches.

Once I get the CPU programmed with Sysex, then I'll assemble it all and take pictures.

Sounds cool! :)

I'm a little confused with how to program CC#s. These are the numbers of the controllers I would like to program into the CPU.

Potentiometers:

CC #s

98,99,100,101,102,103,104,105,106,107,108,109,110, 111

Switches:

CC#s

20,21,22,23,24,25,26,27

Ok--just make a table of the control terminal #s for each CC, and I'll write up a configuration sysex for this. It will be pretty simple. Check section 9 of the hardware user manual to see which control terminals can accept analog input.

Can the switches be momentary and when you push them it goes from 0 to 127, then when you press it again it returns to zero?

Yes. :) This is control terminal mode "CC Toggle" (56h and 57h), new in firmware version 1.2.

The Pots should be 10k correct?

Yes, that will work well.

Let me know if you need more details, and I'll be glad to help out.

[Doug Theriault]

Ok here are the analog in and #'s for each

Potentiometers:

CC #s

98 for analog input 8
99 for analog input 9
100 for analog input 10
101 for analog input 11
102 for analog input 12
103 for analog input 13
104 for analog input 16
105 for analog input 17
106 for analog input 18
107 for analog input 19
108 for analog input 20
109 for analog input 21
110 for analog input 22
111 for analog input 23

Switches:

CC#s

20 for switch input 0
21 for switch input 1
22 for switch input 2
23 for switch input 3
24 for switch input 4
25 for switch input 5
26 for switch input 6
27 for switch input 7

I'm very excited about this!!!!

cheers

doug

[John]

Here's the control terminal configuration sysex:


// Fixed Header and Layer 00h
F0 00 01 5D 04 01
00

// CT #0-7: CC toggle, CC #20-27
00 00 56 00 14 00
00 01 7F 00 00 00
01 00 56 00 15 00
01 01 7F 00 00 00
02 00 56 00 16 00
02 01 7F 00 00 00
03 00 56 00 17 00
03 01 7F 00 00 00
04 00 56 00 18 00
04 01 7F 00 00 00
05 00 56 00 19 00
05 01 7F 00 00 00
06 00 56 00 1A 00
06 01 7F 00 00 00
07 00 56 00 1B 00
07 01 7F 00 00 00

// CT #8-13: Analog CC, CC #98-103
08 00 04 00 62 0F
09 00 04 00 63 0D
0A 00 04 00 64 0B
0B 00 04 00 65 0C
0C 00 04 00 66 0E
0D 00 04 00 67 10

// CT #16-23: Analog CC, CC #104-111
10 00 04 00 68 03
11 00 04 00 69 04
12 00 04 00 6A 05
13 00 04 00 6B 06
14 00 04 00 6C 07
15 00 04 00 6D 08
16 00 04 00 6E 09
17 00 04 00 6F 0A

// Footer
F7


That's it. Note that if you configure the MIDI CPU before you connect the pots, control terminals 8-13 will "float" and thus generate a lot of CC "noise".

Let me know if I can provide more info.

[Doug Theriault]

I can connect the pots later and it won't generate the noise anymore right?

thanks for your quick responses!

[John]

I can connect the pots later and it won't generate the noise anymore right?

thanks for your quick responses!

Yes, of course. I added the warning in case you decided to configure the MIDI CPU and experiment before you had all of the other parts on hand.

[Doug Theriault]

excellent! Going to start putting together tonight :)

[Doug Theriault]

I have 3 pots connected and one switch so far. The Midi indicator light on the Midi CPU goes on and off when using the pots and the switch. But I'm getting no midi signal in or out it seems.

When I load the code from the sysex librarian and try to load it into the CPU the LED indicator light does not go on. I've tried loading the code in 3 different ways without any comments as instructed. Still no LED indicator light goes on, on the Midi CPU after it sends it. It is sending the sysex message out as I notice the indicator out light goes on when I send the message from the computer.

I'm also getting no midi signal out of the Midi CPU.

I'm an experienced builder so my soldering is not to blame (?) Not sure what I'm doing wrong..

I use only one midi connector. Do I need both a midi in and a midi out connected for it to receive and send? Or can I use just one at a time?

thanks

doug

[Doug Theriault]

Ok, I troubleshooted the circuit. I had to wire the midi in's and out's backwards for some reason. The sysex dump worked, but the LED just stays on the whole time. Is that the Midi noise you were talking about? I guess so! Looks successful so far :) I love troubleshooting..

I'm going to finish wiring up the rest tomorrow.

[John]

Sounds good. If you want to prevent the "noise" in the meantime, just temporarily connect control terminals 8-13 to ground. (or, temporarily reconfigure them for logic input...like mode 7Fh)

[Doug Theriault]

Ok. Today I finished testing the CPU, everything tests operational and good. Now the only thing left is to find a place to put power....

[gumbo]

Hmmm...
...looks strangely like the Christmas Tree lights I was trying to fix last year :p

REALLY look forward to seeing this work!!!

[Doug Theriault]

I'm mostly finished with this project today. Just have to put wood filler around where the power will be coming from.

I highly recommend this CPU board. It's the easiest, smallest and most flexible I've ever used and John is a huge help. It's like having your own engineer folks...I've made many things over the years and this has been a pleasure! Thanks for everything John, hope to do more business with you in the future!

Cheers

Doug Theriault

[John]

Doug, thanks for posting the photos! I like the looks of the guitar. What's inside the other enclosures?

[Doug Theriault]

The other enclosures I've built are another MIDI controller, this one with push button encoders, a small feedback synth and a driver. Not pictured is MIDI floor controller made out of a hacked fender amp button box.