Trigger input names and MIDI notes

[Bluebass]

Great work Dmitri!
Are the TRS inputs/triggers hard coded for a MIDI note or can they be assigned to anything? I understand the HH pedal is not a trigger per say, but has a specific function for the trap kit. Would it then be reasonable to assume any of the trigger inputs could be called, and used, as trigger #1, #2 etc? My application of MegaDrum is not a kit per say, but more of a zendrum controller and I will want to re-assign the trigger map depending on the virtual kit I will use.
Can you straighten me out?
Many thanks...

[dmitri]

You can assign any note to any input thus creating your own drum map. And that is not all - you can save/store up to 13 drum maps (in Atmega32 based MegaDrum) in no-volatile memory so that you could easily switch between these drum maps at any time.

[Bluebass]

Thanks. So in my mind, names (kick, tom 2 etc) for the individual trigger inputs are suggestions of their use, rather than fixed use of the input triggers. From the schematic, the HH pedal and Aux 2 inputs are wired differently - i.e. no 100 ohm resistor. Why?

Also, can the TRS inputs be split into two mono triggers?

[dmitri]

Thanks. So in my mind, names (kick, tom 2 etc) for the individual trigger inputs are suggestions of their use, rather than fixed use of the input triggers.

Exactly

From the schematic, the HH pedal and Aux 2 inputs are wired differently - i.e. no 100 ohm resistor. Why?

HH pedal input is different from any other input. On this input HH pedal/controller gets voltage (more exactly current) over 100 ohm resistor and then translates it into output voltage depending on pedal position.

Also, can the TRS inputs be split into two mono triggers?

Yes, they can.

[Bluebass]

Sorry to be a pest...but what about the Aux 2 input and the HH (not pedal) input?

Just trying to understand before committing pad locations on my unit. I have all of the components for two MegaZenDurms and have started the build in earnest. Again, fabulous work and a great contribution to the electronic drumming community. As most of us would likely agree, vdrums/edrums are way too expensive for what they are and especially the Zendrum @~1300 -1800 usd.

[dmitri]

Aux2 input is not any different from any other input. Almost the same for HH input apart from the fact that MIDI channel number for HH pedal signals (chick, splash, CC) is taken from HH input.

[elrules]

The other day I was inspecting schematics to try to understand them. And I found the same difference Bluebass says.

HH pedal:
the two cables it has (1 and 2, 3 is ground) one goes to Vcc with 100Ohm resistor and the other goes directly to digital board. Nothing to say about what you answered.

HH pad input and Kick pad input:
This two inputs go directly to analog connector without passing through the IC's.

Aux 2 pad input:
the two cables goes directly to analog conector without connecting to IC's and without the 100 Ohm resistors.


Besides, trying to understand how IC's work, I suppose they send through ABC pins the input that emitted a signal. And through X pin, 1 or 0 depending on if they emit something, so, with X from IC1 and X from IC2 and A,B,C from both you can say which input triggered something. Is that right? if no, could you explain how it works?

[dmitri]

The inputs that go through 4051 IC's are multiplexed because Atmega32 has only 8 analogue inputs. Other than that these inputs don't differ from the inputs which go directly to Atmega32.

[elrules]

I sae googling a web that said something about multiplexing

http://www.edn.com/archives/1996/062096/13di2.htm

Maybe it is a helpful information

[Bluebass]

OHHHHH I get it!
The reason for the 100 ohmers, the output of the triggers need current limiting and/or series termination - those are long lines to be driving into a high impedance of the 4051 inputs. The outputs of the 4051 are terminated with 100 ohms also when they reach the digital board. Additionally, back on the analog board, the lines from HH pedal and Aux 2 are going directly to the analog connector and continue to the ATMEGA where the inputs are terminated. These could have been any o the triggers - just happened to be the first and last ones (top to bottom) on the schematic. Finally, Pins 10,11, and 12 on the analog connector 2 are actually outputs from the ATMEGA to control the ABC mux lines to the 4051's, which in turn, handle the muxing of the 24 trigger inputs. The answer to at least my own question was in Dmittris responses, it jus took a while to understand the context.