Grids + Midi


#1

Hi, I was wondering if anyone has done the midi expansion on their Grids yet? Could you point me in the right direction towards doing this? Thanks!


#2

Build something like this on stripboard:

The pin marked “TO FPGA” goes to Grids’ MIDI input pin ; while the +5V and GND points are connected to these pins on Grids.


#3

@pichenettes,
Sir , you have just saved me from many sleepless nights wondering how to integrate a particular module into my system. It has been driving me nuts , but Grids (and a bit of DIY) saves the day!

Many Thanks and regards


#4

@Nisus
hope this helps …it is the above circuit exactly ,pin 3 of the chip is bridged to pin 5 of the Midi socket, it’s just difficult to see.

regards


#5

@pichenettes
I am slightly confused in regard starting/stopping the Grids via Midi. I have the Grids Midi RX connected to the VacoLoco GorF XL Midi out via the above optoisolator circuit. A soon as I connect my MicroKorg XL the Grids starts to react , flashing tempo , and the three density values. Is the only way to stop the Grids reacting to turn the knobs (BD/Snare/HH) counter clockwise?
cheers and regards


#6

Yes, the MIDI implementation matches the trigger implementation, with RESET = MIDI START and CLOCK = MIDI CLOCK.


#7

@pichenettes
Thanks , that threw me for a moment, but makes sense.
cheers and regards


#8

Here’s a close up of some strip board for the Grids Midi expansion.


#9

Fantastic! Thanks.


#10

New version … smaller Eurorack panel. DIY Stereo 3.5mm jack to 5 Pin Din cable required.


#11

You skipped the Protection Diode!


#12

@fcd72 try looking underneath :wink:


#13

Wow! You made a Stereo Midi cable?!? :smiley:


#14

@ParanormalPatroler
Certainly … DIN pin 5 to red tip , DIN pin 4 to white ring. It fits behind a much smaller panel.
cheers and regards


#15

And a panel - switch turns MIDI on/off as desired.


#16

all Protection Diode is ok, or some ref is better ?


#17

1N4148 is fine. You don’t really need one…


#18

why when i try some diy it never work … this is fucking simple i dont understand why that not work…
clock is not transmit the only thiings work is sometims when i press play or stop on the Octatrack a led on grid lightning …


#19

Hmmm, I built the interface circuit as shown above on protoboard, except using a 6N137 instead of a 6N138, but with a 10k pull up resistor instead of a 220R pull-up, and with a 1N4148 protection diode (cathode connected to pin 2 of the optocoupler, right?), but Grids just sits there, not recognising any MIDI clock. Grids itself is working fine, no problems, and MIDI clock is definitely being sent - I can see the messages using MIDI Monitor. Just to check, how should the MIDI pins be interpreted in the circuit shown above? My understanding is that the pins are numbered as if looking from behind the MIDI plug. Is that correct? Maybe I have them reversed? Ah, I can check by examining the Shruthi PCB and circuit diagram!


#20

This is brilliant!

When you mount the components on the strip-board, does one join them together on the underside with wires or something?