Highly Liquid Forum facebook twitter google plus rss feed

Go Back   Highly Liquid Forum > Current Products > MIDI CPU

Reply
 
Thread Tools Search this Thread Display Modes
  #1  
Old 03-31-2015, 09:57 AM
bengunn bengunn is offline
Junior Member
 
Join Date: Mar 2015
Posts: 7
Default Advice needed on pedal board programming

I am converting an 18 note pedalboard to MIDI and have bought a MIDI CPU to do it. I am happy about the connection of the pedal switches but would like to add program change, if possible.

Ideally I would like to add to footswitches, one for change up and one for change down, so that pressing the up button sends the next program change number up and vice versa. I would like to add a couple of 7 segment LEDs to display the current program number. Is this possible?

I have read the hardware and software manuals but seem to be lacking something. I don't quite see how the data registers are used, or if they can be incremented or decremented. I am an electronics engineer and very used to programming in 'C' but I cannot quite get my head around this

Just need a pointer in the right direction please.

Richard
Reply With Quote
  #2  
Old 04-01-2015, 07:14 PM
Synthetech's Avatar
Synthetech Synthetech is offline
Moderator
 
Join Date: May 2012
Location: USA
Posts: 711
Default

Hi Richard,

your switches for PC will have to be two part.

One to send a PC using a fixed number, like 1 and a data register.. lets say 11h

we will start 11h at 0.
So first press up or down will be PC 00h+00h= 00h

If we went up, we then need to do the operation Increment to 11h.. usually when we release the switch

see
3.2.22 Logic Input Trigger: Data Register: Increment

in the manual

d0 is the register, 11h in this example and d1 would be 01h to add "1".

we also use
3.2.23 Logic Input Trigger: Data Register: Decrement

to reverse/lower the PC number.







we can indicate 11h's value on two 7 seg. LED's, anything above 99 will flip over and show 00, 01 02...27 since we dont have a hundreds digit.


the data registers are listed in the beginning of the manual.
multipurpose registers are 11h, 12h, 13h... on up to 1Ch

each register is a 8bit value/memory location. We can usually only use the first 7bits for multipurpose registers... thus a limit of 127 in value for most things.

we use 8 bits for LED's and the switches and some other registers.

register 00h is the first 8 CT's when used in a switch matrix. thus reg. 00h is a Switch Register. It's how the select line knows where to scan for switch activity.
Reply With Quote
  #3  
Old 04-02-2015, 08:29 AM
bengunn bengunn is offline
Junior Member
 
Join Date: Mar 2015
Posts: 7
Smile

Thanks for the reply Synthetech, I will give that some thought and post again when I get stuck

It is good to know that I should be able to achieve what I would like to do.

Richard
Reply With Quote
  #4  
Old 04-02-2015, 01:14 PM
bengunn bengunn is offline
Junior Member
 
Join Date: Mar 2015
Posts: 7
Default

Hi Synthetech,

I have now gone through your answer with the Firmware Manual and am pretty sure that I understand how to do it now.

Many thanks for your answers, it is all in the Firmware Manual but it is a bit difficult to see how to join it up, your answer did that, thanks.

I just need to find some time to build the MIDI CPU into the pedal board now

Richard
Reply With Quote
  #5  
Old 04-02-2015, 02:04 PM
Synthetech's Avatar
Synthetech Synthetech is offline
Moderator
 
Join Date: May 2012
Location: USA
Posts: 711
Default

yea it kinda takes a bit extra explanation for anyone not familiar with uControllers like PICs and Arduino

the CPU has three primary 8bit ports. the switch registers 00 01 02 are on those three.

also check the table in the Hardware manual

9.0 Control Wiring

it shows what can be switches, pots, outputs for matrix's...


utilize the two transitions, switch down/on, switch up/off both can do an operation
you can also add in a 2nd or more layers to add in more ops or to isolate specific values to a PC Note, CC... or have Banks to switch between.
Reply With Quote
  #6  
Old 05-21-2016, 04:42 PM
bengunn bengunn is offline
Junior Member
 
Join Date: Mar 2015
Posts: 7
Default Programming not working

I have finally got around to modifying my pedalboard to add the MIDI CPU.

I have done initial tests and successfully downloaded V1.4 Beta firmware to the MIDI CPU, so I know the MIDI is working correctly.

The configuration has 18 pedals ina 6 by 3 matrix, 3 seven segment LEDs to show patch number and patch +1, -1, +10 and -10 buttons.

I think that I have understood how to configure the MIDI CPU to do what I want to do but when I download my configuration, it is not accepted and the Patch increment and decrement buttons just send Note On messages.

The 2 layers are downloaded separately from .syx files.

I have attached the txt version of the configuration file and would appreciate knowing what is wrong with it.

Thanks,

Richard
Attached Files
File Type: txt Bass Pedals MIDI CPU Configuration.txt (4.9 KB, 68 views)
Reply With Quote
  #7  
Old 05-22-2016, 05:25 PM
bengunn bengunn is offline
Junior Member
 
Join Date: Mar 2015
Posts: 7
Default

OK, problem sorted. I had lost the F0 at the start of the header when I copied and pasted it from the manual. I also missed the fact that the txt to syx converter does not accept comments, I deleted those and it downloads and works fine now.

Richard
Reply With Quote
  #8  
Old 06-06-2016, 07:57 PM
bengunn bengunn is offline
Junior Member
 
Join Date: Mar 2015
Posts: 7
Exclamation Problem with repeated MIDI notes on matrixed keys

My pedals are complete and work, sort off.

I have 18 pedals arranged as a 3 x 6 matrix and they work correctly except that, when a pedal is held, you get repeated MIDI on and off at what appear to be random intervals; the pedals do not all behave the same but all give the repeats when held.

Looking at the pedal switch signals with a 'scope, I see that the scan signal normally goes low for 10us but occasionally goes low for about 60us and this coincides with the repeated note. The scan signal does this whether or not a pedal is pressed, so it is not dirty switch contacts, which I suspected at first.

Other than the pedal switches, I have patch +1, -1, +10 and -10 buttons and a 3 digit 7 segment LED showing the last patch change sent and that all works perfectly.

I am a retired electronics engineer and this one has me puzzled; help please!

In case it helps, I have attached both a commented configuration file and one with the comments removed which I used to generate the two SYX files for Layers 0 & 1.

Also, I have programmed my MIDI CPU with V1.4 Beta Firmware.

Richard Gunn

Last edited by bengunn; 06-06-2016 at 08:04 PM. Reason: Forgot to state Firmware Version
Reply With Quote
  #9  
Old 06-09-2016, 07:28 PM
bengunn bengunn is offline
Junior Member
 
Join Date: Mar 2015
Posts: 7
Default Problem solved by changing back to V1.2 Firmware

Having had no response, I decided to try reverting back to V1.2 Firmware, I reprogrammed the MIDI CPU with V1.2 and then amended my configuration to work with V1.2 (LEDs can only run from 0 to 120 not 1 to 128 and the register for the last PC does not exist so I changed to use register 0x11).

This appears to have solved the problem, so it would appear that something in Firmware V1.4 Beta does not work correctly when using matrixed switches with the rest of my configuration.

Richard
Reply With Quote
Reply

Thread Tools Search this Thread
Search this Thread:

Advanced Search
Display Modes

Posting Rules
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is Off

Forum Jump


All times are GMT. The time now is 09:16 PM.


Powered by vBulletin® Version 3.8.7
Copyright ©2000 - 2017, vBulletin Solutions, Inc.