MIDI Footcontroller for Eleven Rack.

[JohnGrinalds]

Howdy,

So my MIDI CPU is on its way, and I'm looking to build a MIDI footcontroller for my Eleven Rack guitar processor. I had a few questions before I create my layout.

1. As far as I understand, a rotary encoder can/will act like a potentiometer that can turn continuously and freely. Is this accurate?

2. If I wanted LED indicators to light up when using latching SPST switches, I know I could write some code and utilize some of the other terminal points, however, could I instead just wire the LEDs directly into the SPST switches themselves, that way they would turn on when the switches are engaged? Or would there be voltage/current issues with this approach?

3. Say I have a few SPSTs, a rotary encoder or two, and some potentiometers, they all have a certain function/issue a certain command. Is it possible to then wire things up so that they could also perform completely different functions upon depressing a push-button switch (or something similar)? In other words, can I toggle the functions of all the buttons/encoders/pots by toggling just one switch?

Thanks so much!

John

[Synthetech]

Funny thing, I was about to post about a foot controller myself in the near future using a racing pedalset from a game controller...


Perhaps I can chime in here a little to help out.

1. Encoders are NOT like potentiometers at all.. short of the rotary encoder's appearance. A pot will vary resistance, an encoder will send out pulse signals and a decoder (built into the Midi CPU) will decode the signals to interpret if you turned up or down and by how much.

2. You could hardwire a LED to your switch, if the voltage that is passing thru the switch isnt too high for it, or you can add resistance appropriate for the circuit. Keep in mind that the Midi CPU can control LED lights as well.

3. I think you are talking about creating "scenes". Where all your pots/encoders/switches all start out controlling certain things, but you push a "scene/mode" switch and all of them change what they control.
I'm not sure if just one pushed button can change multiple controllers.. but I do know it can change at least one.

Check out the thread I made that has a similar situation that was answered better than I can explain here.
http://forum.highlyliquid.com/showthread.php?t=803

[JohnGrinalds]

Okay, thanks Seeker! I'll try to have a layout and an idea of what I want to do by this weekend.

[J.D.]

There was some talk prior to the last update about a function that could toggle configuration layers that I'd still be very interested in. But that was for a very specific purpose that l hOnestly have found a way around that I can hardly complain about.

Currently each terminal can be configured on four different layers. Some functions prevent using different layers because of the way they are built into the firmware, and some multiple-layer configurations will become occluded when sent to certain hardware/ software (I've found). But you can create some very comprehensive multi-function behavior by using different channels, layering CCs and using data registers to control interaction. You might want to explore the capabilities of the software or device that you're planning to control to find some answers too. A little vague, but the forum's here to help when you have some more info.

[Jim McDougall]

JD is correct -- By toggling layers you can make the same input perform different functions (messages). however, as JD indicated, there are restraints and sometimes the receiving equipment can't handle what you are doing. Rough out a design of what you are trying to accomplish and indicate what the Eleven Rack is expecting to receive as messages for the functions that are to be changed via midi. Then we all can offer some solid help.

[JohnGrinalds]

Okay, here’s what I’d like to do.
I’m looking to build a controller for the Avid Eleven digital guitar effects processor. The parameters I want to change I have denoted with the correct (I hope) CC numbers.

I think I’ll hold off on layers for the time being; I can implement that fairly easily later on, right?

Here’s what I got:

7 Rotary Encoders:

CC#s
101-Knob 1
102-Knob 2
103-Knob 3
104-Knob 4
105-Knob 5
106-Knob 6
17-Rig Volume


5 Latching SPSTs;

CC#s
25-Dist
50-Mod
28-Delay
36-Reverb
63-FX 1
86-FX 2

3 Momentary SPST’s:

CC#s
32-Rig Back
0-Rig Forward
64-Tap Tempo


1 Potentiometer

CC#s
7-Volume Pedal


There are LEDs on there that I may try to wire into the SPST switches.

One other question: what is the best way to connect to the MIDI CPU terminals? Are there lugs I can buy, or should I just solder onto the board?

And let me know if I missed something or need to provide more information.

Thanks!

John

[JohnGrinalds]

I just realized I had too many components... :/ so I edited my last post and removed the wah pot and latching switch.

[Jim McDougall]

The midi cpu use .100 spacing There are post strips you can buy from digikey and Mouser that will solder in as a compete strip or I prefer to cut it with diagonal pliers int o smaller sections -- easier to insert and solder if you look up this part # on digitkey A1919-Nd and then use the link to go to the page you will find various connecots that will fit this spacing so you can use various widths of ribbon cable and the appropriate connectors to hook up various sections of components

[John]

Hi John, welcome.

Cool project. Thanks for posting the image.

If you have a latching switch that you want to use to control an LED at the same time it provides MIDI CPU input, you can wire it this way:



Extensive discussion of pin headers and terminal blocks can be found here:

http://forum.highlyliquid.com/showthread.php?t=535

http://forum.highlyliquid.com/showthread.php?t=260

Hope this helps.

[John]

By the way, if you need implementation advice, please post a list of MIDI CPU control terminals 0-23 and how you plan to use each.

[JohnGrinalds]

Super! Sounds good. I want to do some testing this week to see what components I actually want to use.

[Wildfire]

Hi John,
I'm asking for some advice on controlling an Eleven Rack also on a separate thread using a Zoom G9 unit which I have. http://forum.highlyliquid.com/showthread.php?t=816

Looking at your layout in terms of rotary encoders, pedals etc. then I thought I'd mention the Zoom G9 as possible raw material?
I know it wont be all your own but for around £140 GBP off ebay you could pick one up and it might save some effort and give you most of the hardware?

If I can get it to work then it would be pretty cool. The four way 'Z Pedal' (up/down/left/right simultaneously looks like a bit of a gimmick but I do actually use it!).

[JohnGrinalds]

Thanks for thinking of me, Wildfire. That Zoom G9 is pretty impressive; it's almost like an Eleven Rack in itself. I would probably be hesitant to gut one just for the parts. Hopefully I can keep my component costs low. Thanks though!

[JohnGrinalds]

Quick question: The manual says the MIDI CPU can handle 3.3 -12 volts DC. My power supply is running about 12.24 VDC. Am I at risk of frying my CPU?

[John]

Originally Posted by JohnGrinalds

Quick question: The manual says the MIDI CPU can handle 3.3 -12 volts DC. My power supply is running about 12.24 VDC. Am I at risk of frying my CPU?

That should work ok.

[Wildfire]

Originally Posted by JohnGrinalds

I would probably be hesitant to gut one just for the parts. Hopefully I can keep my component costs low. Thanks though!

No problem John, I was thinking more of using the entire thing - housing and all - but rewiring the hardware to your requirements, rather than gutting it. But then you'd be limited by the layout etc. I suppose.

Good luck with the project.

[JohnGrinalds]

All right I think I’m almost there, but I’ve run into a few issues.

So far, I’ve wired everything temporarily to the lid of a shoebox, just to get a feel of the size and such. I’ve attached a picture to give you some idea of what I’m looking at.

I'm having no problems with the first seven terminals (those will be hooked up to the switches), which is good. I’m running into isses with the potentiometers though. Right now when I turn any one of the pots, it seems to work just fine, judging by the ACT light on the CPU—the varying stream of blips corresponding to the speed of the pot rotation. HOWEVER, on the Eleven Rack, the value I’m trying to adjust jumps instantly to 10, and remains there. I can’t change it to a different value. This happens for all the pots. It's like I'm instantly grounding or disconnecting the pot (I'm not sure which). I got this function to work with just one pot, so maybe there’s an issue when I hook them all together? They’re all 5Kohm pots. I did notice that, when I hooked a multimeter to one of the pots in the parallel, it read much less than 5K ohms (something like 700 ohms maybe). How do I resolve this issue? Have I missed something?

Also, my rotary encoder did not seem to be working. Although I suspect my wiring may be the issue here.

Here is the code I’m using:

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

//Distortion
//Latching Switch
// CT # 0: CC #25
00 00 4C 00 19 7F
00 01 4C 00 19 00

//Modulation
//Latching Switch
// CT # 1: CC #50
01 00 4C 00 32 7F
01 01 4C 00 32 00

//Delay
//Latching Switch
// CT # 2: CC #28
02 00 4C 00 1C 7F
02 01 4C 00 1C 00

//Reverb
//Latching Switch
// CT # 3: CC #36
03 00 4C 00 24 7F
03 01 4C 00 24 00

//FX 1
//Latching Switch
// CT # 4: CC #63
04 00 4C 00 3F 7F
04 01 4C 00 3F 00

//FX 2
//Latching Switch
// CT # 5: CC #86
05 00 4C 00 56 7F
05 01 4C 00 56 00

//Tap Tempo
//Momentary Switch
// CT # 6: CC #64
06 00 4C 00 40 7F

//Toggling Function
//Momentary Switch
// CT # 7: CC #?
07 00 4C 00 00 7F
07 01 4C 00 00 00

//Knob 1
//Potentiometer
// CT # 8: CC #101
08 00 04 00 65 03

//Knob 2
//Potentiometer
// CT # 9: CC #102
09 00 04 00 66 04

//Knob 3
//Potentiometer
// CT # 10: CC #103
0A 00 04 00 67 05

//Knob 4
//Potentiometer
// CT # 11: CC #104
0B 00 04 00 68 06

//Knob 5
//Potentiometer
// CT # 12: CC #105
0C 00 04 00 69 07

//Knob 6
//Potentiometer
// CT # 13: CC #106
0D 00 04 00 6A 08

//Rig Volume
//Rotary Encoder
// CT # 14: CC #17
0E 00 14 00 11 18
// CT # 15: CC #17
0F 00 14 00 11 18

//Volume Pedal
//Potentiometer
// CT # 16: CC #7
10 00 04 00 07 09

//Wah Pedal
//Potentiometer
// CT # 17: CC #4
11 00 04 00 04 0A


//Wah On-Off
//Latching Switch
// CT # 18: CC #43
12 00 4C 00 2B 7F
12 01 4C 00 2B 00

// CT # 19: CC #0
13 00 4C 00 00 7F
13 01 4C 00 00 00

// CT # 20: CC #0
14 00 4C 00 05 7F
14 01 4C 00 05 00

// CT # 21: CC #0
15 00 4C 00 04 7F
15 01 4C 00 04 00

// CT # 22: CC #0
16 00 4C 00 03 7F
16 01 4C 00 03 00

// CT # 23: CC #0
17 00 4C 00 02 7F
17 01 4C 00 02 00

// Fixed Footer
F7

For what it’s worth, I didn’t hook up terminals 16-23. Don’t know if that would be an issue.

Let me know if I can provide any other information.

Thanks!

John

[Jim McDougall]

John

there is a small problem with your config strings for the pots

//Knob 1
//Potentiometer
// CT # 8: CC #101
08 00 04 00 65 03


look at this table -- it is table 2.2.2 on Page 8 in the firmware manual
Data Registers
Register Address Control Terminal #
03h 16
04h 17
05h 18
06h 19
07h 20
08h 21
09h 22
0Ah 23
0Bh 10
0Ch 11
0Dh 9
0Eh 12
0Fh 8
10h 13


so for terminal 8 you should be using data register 0F not 03
and so on through your config. Currently you are getting the garbage that is in the registers you are using as none of them are actually getting real data as they are for the analog inputs that are not configure 16 - 22

[JohnGrinalds]

That was it! I fixed the registers and the pot work perfectly. Thanks so much!

Now I have another question: Is there a way to set up the CPU so I can use the push button switches to send Program Changes as well? In other words, right now, they just send Control Changes; how can I toggle, on the fly, between having them send Control Changes and Program Changes? Does that make sense?

Thanks!

John

[Jim McDougall]

Rev 1.3 introduces the ability to turn layers on and off.

see the sections in this manual

http://highlyliquid.com/support/docs...re-Ver-1-3.pdf


So -- layer 0 would stay as you currently have it

layer 1 would setup the same switches but for program changes and you would repeat the analog config for the pots.

Now two terminals would control which layer is on or off. Accomplished by one double pole switch .

Dual function switching. In theory since there are 4 layers you could drive yourself to distraction