MB9090 input schematics ok?

[pcbatterij]

Hey all,

I am designing a seqV4 board for my 9090.

I am going to use tactile swithches from OMRON B3F-4000 ( mouser: My link) or E-Switch TL1100F160Q (mouser: My link).

In my input schematic on U2 PIN2 I have used (hopefully) the correct component. Would it be possible to check if I have used the correct pins of the switch?

I am using KiCAD and have made PIN 2 and PIN 4 of the switch unused.

You can of course also check the rest of the schematics :tongue:

cheers Jef

MB909 input.pdf

[jojjelito]

Your switch pinning looks OK.

I'm curious as to why you used one data line per switch instead of the diodes plus matrix arrangement used in the MB6582? I guess your way (the classical way) is far easier to debug and conceptually grasp though :thumbsup:

I've got no idea at thi point in time if a resistor to VCC like you did it or a resistor to GND is to be preferred - someone else maybe knows. Guess I should read up some before forming an opinion (what - that's like thinking before you speak?!).

/J

[pcbatterij]

Thanks for the reply jojjelito.

concerning the matrix arrangement: I have looked at the DOUT schematics and the DIN schematics of the MB6582.

As far as I understood it these two different matrixes are connected to 74HC595's and 74HC165's using transistors?? But as far as I understand it, it is not a scalar because the wiring is completely different (one matrix for buttons and one matrix for led's where in a BLM using a scalar the matrix is one with all the buttons and all the led's).

I also looked at Wilba's schematics: I could not find transistors in there?? And I am using less buttons (40 in total) and only one or two encoders. And I am also going to use a BPM 3*7segment led display. I am not experienced enough to change the schematics of Wilba so it fits my design and will still be recognized by the seqV4 software.

I would realy like to build a matrix based MBSeq but I am not sure how to do it.

cheers,

Jef

Edited October 10, 2011 by pcbatterij

[nebula]

I'm curious as to why you used one data line per switch instead of the diodes plus matrix arrangement used in the MB6582? I guess your way (the classical way) is far easier to debug and conceptually grasp though :thumbsup:

For a one-off personal design, the "classical way" is the way to go. The software is already written this way, and there really isn't a big savings in ICs. Here he's using 4 SR's - yes you could matrix it down to 2 SR's, but then you've gotta stick in 32 diodes and modify some code.

I've got no idea at thi point in time if a resistor to VCC like you did it or a resistor to GND is to be preferred - someone else maybe knows.

AFAIK all the MIDIbox projects have the resistor to VCC ("pull up resistor"), but can be easily changed to the opposite logic. Check out the DIN schems on ucapps.de.

[jojjelito]

For a one-off personal design, the "classical way" is the way to go. The software is already written this way, and there really isn't a big savings in ICs. Here he's using 4 SR's - yes you could matrix it down to 2 SR's, but then you've gotta stick in 32 diodes and modify some code.

AFAIK all the MIDIbox projects have the resistor to VCC ("pull up resistor"), but can be easily changed to the opposite logic. Check out the DIN schems on ucapps.de.

Mmm, the matrixed version sure is trickier. Plus, if you don't buy loads of diodes, I suspect that you don't even save money. It's all pull-up to the bumper at ucapps.de it seems. Who knew, I was too caught up in my modular when I answered. Thus, I only said something about what I could easily check at that time

/Il Scuro

[pcbatterij]

For a one-off personal design, the "classical way" is the way to go. The software is already written this way, and there really isn't a big savings in ICs. Here he's using 4 SR's - yes you could matrix it down to 2 SR's, but then you've gotta stick in 32 diodes and modify some code.

AFAIK all the MIDIbox projects have the resistor to VCC ("pull up resistor"), but can be easily changed to the opposite logic. Check out the DIN schems on ucapps.de.

Nebula,

Thanks for the reply,

The schematics isn't finished yet I do need an extra 8 buttons and at least one encoder (for BPM). Thus i need another two SR's for the extra 8 buttons and the encoder(s).

I quickly made a different schematic, if this is what you mean with matrixing it down to 2 SR's then I will go forward with this, else I will continue with the classical way.

Thanks for all the help

Cheers Jef

MB9090 Matrix Input v1.2.pdf

[nebula]

I quickly made a different schematic, if this is what you mean with matrixing it down to 2 SR's then I will go forward with this, else I will continue with the classical way.

Hey Jef, yeah that's basically what I mean, but unless you want to dive heavily into the existing MB code, I wouldn't do it. I would just add more SR's for your buttons.

If you plan to do this on something other than perfboard (i.e. home etch or professional fab), then may I suggest surface-mount 74HC165 IC's (as several of us have been playing with). They save a LOT of room!