DIY Arduino MIDI Mixer "Crius HERMES V1.0"

Hi!

I am Crius and I LOVE MIDI Controllers!

The last couple of years I started learning about electronics from nothing to be able to build my own MIDI controllers that would serve my needs , taste and be cheaper overall in comparison with the branded products.

The Crius “HERMES” MIDI Mixer consists of 8 potentiometers and 11 buttons with which we can control parameters of the VST-Plugin or DAW we play music

and 32 LEDs divided into 4 columns (i.e. 8 LEDs for each track) that show us live the Volume value of each track within the DAW program by turning on the corresponding LEDs in each column.

Of the 11 buttons, 8 can be assigned to any DAW parameter we want.

The 2 of the 11 buttons are BANK buttons allow us to assign the 8 potentiometers to 8 more parameters as if we were changing "page" and have 16 potentiometers in 2 "pages".

Finally, there is another button with which we change the effect of the LEDs from "bar" filling to "moving dot" depending on the Volume value.

HARDWARE COMPONENTS :

1. LEDS 3mm x32
2. Resistors 220Ω x32
3. Shift Registers 74HC595 x4
4. Resistors 10kΩ x4
5. Analog Multiplexers 74HC4051 x2
6. Linear Rotary Potentiometers 10kΩ x8
7. Arduino Leonardo Pro Micro (clone) x1
8. Momentary switches x11
9. IC sockets 16 pin x6 (optionally)
10. Micro USB cable x1

SOFTWARES USED :

1. Fritzing (Schematic Designing)
2. Arduino IDE

I used Fritzing to design the circuit for the potentiometers , leds and buttons.I also put 4 mounting holes at the corners of the PCB having in mind that it will be mounted in the future in a custom 3D Printed case.

I used a base to solder the components to the PCB because some of them need to be soldered from the back side.

I'll start by soldering the 32 resistors in the places that have an R and the number of each resistor next to it (R1-R32).

Next I will solder the resistors and then cut the pins that stick out from the back.

Now I will solder the 32 LEDs to the positions next to the resistors (LED1-LED32).

I will solder the LEDs from each row and then continue to the next, because I will bend their pins from behind and they will get in the way if I put them all together.

As before I will cut off the Pins that stick out so they don't get in the way after I soldering them to the PCB.

Now I will solder the 4 10kΩ resistors located on the top of the board (R33-R36).

These resistors are used to reduce the flickering of the LEDs that are off when displaying the volume.

Next (optionally) I will solder the 6 IC Sockets to place later the Multiplexers and Shift Registers on them.

To be able to solder them to the PCB I will have to fix them first with some paper tape since the pins will be soldered from the back side of the PCB.

BE CAREFUL to match the notch on one side of the IC Sockets with the pattern on the PCB!

It would be good to first solder the 4 pins located in the corners of the IC Sockets to stabilize them better and solder the rest afterwards for greater security

Since I didn't have an IC Socket for the Arduino Pro Micro I used female headers.

To stabilize the female headers for soldering I will use the Arduino Pro Micro to hold them at the right distance and tape them with some tape so I can solder the pins to the back of the PCB.

Potentiometers (POT1-POT8) are now in order to be soldered.

Now in order to solder the buttons since I haven't designed yet the case for the Crius HERMES MIDI Mixer , I can put whatever kind of buttons I want, so I chose the ones that look like arcade buttons and soldered them by bending their pins to the side carefully so they don't get cut.

In order for them to be soldered easily, I must first put glue on the PCB where the Pins will be soldered.

Then I will place the pins from the buttons and heat them with the soldering iron until the glue melts and they stabilize.

Now we will place the 74HC4051 Analog Multiplexers on the bottom left of the PCB.

BE CAREFUL to match the notch on one side of the Multiplexers with the pattern on the IC Sockets!

Again BE CAREFUL to match the notch of the Shift Registers with the notch in the IC Sockets!

THE PCB IS READY!!!

I used Arduino IDE to write and upload the code to the Arduino pro micro.

To upload the code to Arduino we need to download the Arduino IDE

After you install the Arduino IDE, download and open the Crius_HERMES_MIDI_Mixer_v10.ino file so we can Upload the code to the Arduino

I used the "Control Surface" Library for the code.

You must manually download and install the Control Surface library to the Arduino IDE.

(A BIG THANKS to "Pieter P" the creator of the Control Surface library for his GREAT work!)

To install the Library to the Arduino IDE go to the menu Sketch -> Include Library -> Add .Zip Library and select the zip file downloaded from the Github.

Then we have to select Board from the menu Tools -> Board -> Arduino Leonardo

And the Port from the menu Tools -> Port -> the port we have connected the Arduino

Now we can click Upload and upload the code.

1.Arduino IDE : https://www.arduino.cc/en/software

2.Fritzing : https://fritzing.org/download/

I hope you enjoyed the proccess and made one for your self!

You can find everything you need for this project INCLUDING INSTRUCTIONS IN ENGLISH to my website : www.criusdigitalstudio.com

You can find my projects and support me at the following social media and websites:

1.Crius Digital Studio Youtube Channel

2.Crius Digital Studio Thingiverse Profile

3.Crius Digital Studio Github Profile