operators123

Couple of questions about MIDIbox NG

6 posts in this topic

Hi, I've been looking into building a new DJ Controller and I've settled on using MIDIbox NG with the STM32F4 core module as this is certainly the best option out there (my last controller was made with arduino mega and the amount of features this has compared to that is crazy).

These are the features I plan to have:

 

- About 56 tactile buttons connected directly to a DIN module (basically 7 daisy chained 165's)

- About 140 controlled LEDS directly connected to a DOUT module (again about 20 daisy chained 595's) some are going to be flashed on/off went sent data from Traktor, but also I plan to have two big LED rings around the jogwheels consisting of about 24 led's each side

- Three encoders (two with no detents on with detents)

- About 16 pots, rotary and slide connected to one AINSER_64 module.

 

I have a couple of questions:

- Can I connect encoder pins and push buttons to the same DIN module?

- What forward current does the 595 run the LED's at? It has 220 ohm resistors in front of each input so this looks like 15ma . Since I have 140 LED's does that mean 2.1A of current?

- Does this design seem feasable? I do have a bit of experience with circuits and coding from my last project

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Hi,

 

I strongly recommend you to organize the buttons in a 8x8 DIN matrix, and the LEDs in a 8x16 DOUT matrix (for 128 LEDs) + 8x8 matrix (for the remaining LEDs)

 

This will also solve the current consumption issue, because with 8 rows the current consumption is (appr.) divided by 8

16 rows are not recommended -> LEDs not bright enough

 

The 8x8 DIN matrix will allocate 1 DIN SR and 1 DOUT SR

The 8x16 DOUT matrix will allocate 3 DOUT SRs

The 8x8 DOUT matrix will allocate 2 DOUT SRs

 

The LED rings will require another 8x16 matrix: +3 DOUT SRs (note: 16 LEDs are max. supported)

Encoders require +1 DIN SR

 

Makes: 2 DIN SRs and 9 DOUT SRs, accordingly one MBHP_DINX4 and three MBHP_DOUTX4

 

- Can I connect encoder pins and push buttons to the same DIN module?

 

yes

 

 

- Does this design seem feasable?

 

This is actually a very simple design; of course it's feasible :)

 

Best Regards, Thorsten.

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Ah right, thanks for the feedback :smile:

I'm going to look then into wiring all the digital IO's as matrixes, it seems as if this means I can use less shift registers and save a bit of money then.

 

 

EDIT:

Wow it actually looks like wiring the buttons in a matrix is much better, I now only have to carry 16 signals from my frontpanel PCB to the module as opposed to 56 for each button.

 

My only worries so far are in the programming. When I say roughly 140 LED's I mean about 40 of them being VU meters, about 56 being switched on/off and 48 being the LED rigs for the jogwheels. Hopefully even while in a matrix each LED can be adressed individually so I can give each one a specific funcion.

Edited by operators123

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Ok, just going to bump this post to post a diagram of my connections to make sure I havn't made any mistakes as getting my head round this was a bit confusing:

(I apologize if this is too big)

 

I've drawed a diagram to show what is going on, essentially I have now:

-one 8x8 button matrix

-one 8x8 led matrix for 64 jogwheel leds (32 on left and right deck)

-one 8x16 led matrix for panel illimination leds (so about 128)

-encoders connected direct to core:

 

post-21412-0-38978500-1422296460_thumb.p

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Ah perfect, I've been looking all over for examples!

 

Will have a look at these then draw up a new digram

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