❗️ This is now deprecated in favor of https://github.com/ghostintranslation/motherboard
MOTHERBOARD9 is a 9 controls Teensy 4.0 + audio board platform.
MOTHERBOARD6, MOTHERBOARD9 and MOTHERBOARD12 allows for any combination of pushbuttons, potentiometers and encoders, in addition to leds. The footprints of those 3 type of components are stacked together so that only one pcb can be used for many different modules.
The MOTHERBOARDs come with 2 boards, one on which the inputs and leds are soldered to, and one on which the Teensy and other components are soldered to. Both boards are attached by multiple pin headers.
Note: MOTHERBOARD9 shares the same B board as MOTHERBOARD12, this is why on the schematics it goes up to 12 inputs of each type. JP4 component can be avoided for this module.
I sell the PCBs if you wish to build it. You can get them here: https://ghostintranslation.bandcamp.com/merch/motherboard9-pcb
Due to the use of the audio board, the available pins are very limited. Looking at the Teensy audio board page (https://www.pjrc.com/store/teensy3_audio.html) we can see only pins 0, 1, 2, 3, 4, 5, 9, 14, 16, 17, 22 are available. Also looking at Teensy pins (https://www.pjrc.com/store/teensy40.html), only 14, 16 and 17 from this subset are analog inputs.
So the use of multiplexers is required to be able to read pushbuttons, potentiometers, encoders or to lit leds. In addition, a matrix design is used for the encoders to reduce the number of inputs required as each of them has 3 inputs.
On this design, pin 22 will switch from input to output very fast to lit the leds and read the inputs.
Dependng on the type of inputs used, not all multiplexers may be required.
- IC1 and IC2 = Mux for LEDs
- IC3 and IC4 = Mux for potentiometers
- IC5 = Mux for encoders
- IC6 = Mux for encoder's switches and pushbuttons
- IC7 = Mux for midi channel dipswitch
- IC8 = Main mux, always required
A few examples:
If you only use potentiometers, you won't need IC5 and IC6. Or if you don't have any led you won't need IC1 and IC2. Or if you have less than 9 LEDs you won't need IC2. Or if you don't want to use a dipswitch to select the midi channel, you won't need IC7.
Here is the list of components you will need:
- MOTHERBOARD9A pcb
- MOTHERBOARD9B pcb
- Teensy 4.0
- 14 pins male headers, or longer and can be cut to length
- 14 pins female headers, or longer and can be cut to length
- 1x 5 pins female header
- CD4051 multiplexers (number varies)
- DIP16 IC sockets (number varies)
- 3.5mm jack connectors
- Thonk: https://www.thonk.co.uk/shop/3-5mm-jacks/ (the Thonkiconn)
- 4 positions dipswitch
And here is the list of optional components according to your wants:
- Teensy audio board
- Vertical linear 10k potentiometers
- Modular Addict: https://modularaddict.com/parts/potentiometers-1/9mm-t18-vertical-potentiometers
- Synthrotek: https://store.synthrotek.com/9mm-Vertical-Potentiometers_p_649.html
- Thonk: https://www.thonk.co.uk/shop/alpha-9mm-pots-vertical-t18/
- DigiKey: https://www.digikey.ca/en/products/detail/tt-electronics-bi/P0915N-FC15BR10K/4780740
- D6 pushbuttons
- Rotary encoders
- 1 resistor ~ 22ohm
- LEDs
In order to run any sketch on the Teensy you have to install the Teensyduino add-on to Arduino. Follow the instructions from the official page: https://www.pjrc.com/teensy/teensyduino.html
Then open the sketch located in the Motherboard9 folder of this repo.
In the Tools -> USB Type menu, choose "Serial + midi".
Then you are ready to compile and upload the sketch.
The MIDI input and output jacks are directly connected to the Teensy serial input and output. That means there is not protection against voltage or current. It is primarily ment to connect 2 of these modules, or 2 Teensy together. If you want to connect something else to it make sure to provide a maximum of 3.3v and 250 mA.
Copy the Motherboard9.h in your project. Then just include it and start using it.
Motherboard9 is a singleton, so to instanciate it you do this:
Motherboard9 * motherboard = Motherboard9::getInstance();
Then in the Setup you have to call Motherboard's init with the type of controls you have on the board:
// 0 = empty, 1 = button, 2 = potentiometer, 3 = encoder
byte controls[9] = {2,2,2, 2,2,2, 2,2,2}; // From left to right and top to bottom
motherboard->init(controls);
Then in the loop you have to call Motherboards update:
motherboard->update();
LEDs are controlled by setting their status according to:
- 0 = Off
- 1 = Solid
- 2 = Slow flashing
- 3 = Fast flashing
- 4 = Solid for 50 milliseconds
- 5 = Solid low birghtness
void setLED(byte ledIndex, byte ledStatus);
The first parameter called binary is a number that will be represented in binary with the least significant bit on the left. Ex: 9 = 100100 => LEDs of indexes 0 and 3 will be lit.
void setAllLED(unsigned int binary, byte ledStatus);
void toggleLED(byte index);
void resetAllLED();
- In the case of a potentiometer it will return between 0 and 1023.
- In the case of a button it will return 1 for push 0 for release.
- In the case of a rotary it will return the number of rotations since the last get.
int getInput(byte index);
Because an encoder is like 2 controls, the rotary and the switch, we need this function in addition to getInput.
int getEncoderSwitch(byte index);
The value depends of the ADC resolution, which is 10 by default and can be set to 12 or 8.
With a resolution of 10 bits, the maximum value is 1023.
int getAnalogMaxValue();
It should always be 0, but if your potentiometers are not that accurate they could return bigger than 0 as a minimum value. You could then change the return value of that function to match the real minimum. This will ensure that getInput always returns a minimum of 0 and a maximum of 1023 that corresponds to the actual min and max.
int getAnalogMinValue();
This is set by the dipswitch and read only once when powered on. If no dipswtich is soldered then the channel will be 1.
byte getMidiChannel();
Callbacks are a very good way of handling inputs. Using them instead of reading getInput in the loop will make your code easier to read and maintain.
This will be triggered only once on release.
Can be used for a button and for a rotary switch.
fptr is a void() function.
void setHandlePress(byte inputIndex, PressCallback fptr);
This will be triggered only once on release after a long press. If an input has both Press and Long Press callbacks then only one of them will be triggered according to the duration of the press.
fptr is a void() function.
void setHandleLongPress(byte inputIndex, LongPressCallback fptr);
This will be triggered once every time a turn is detected.
fptr is a void(bool value) function. value is either 0 for a left rotation or 1 for a right rotation.
void setHandleRotaryChange(byte inputIndex, RotaryChangeCallback fptr);
Here are the dimensions for any module size. Every column is following the same rules. So the size of a module depends on the number of column. 2 columns = 2x20mm = 40mm, 3 columns = 3x20 = 60mm ...
- Encoders are skipping turns sometimes
- Maybe test with faster multiplexers
- Rev 3 (current) using more multiplexers because of the limited available pins.
- Rev 2 added multiplexers, but wasn't taking in account the forbidden pins from the use of the audio board.
- Rev 1 was using matrices for potentiometers, which doesn't work.
This project is licensed under the MIT License - see the LICENSE.md file for details
You can find me on Bandcamp, Instagram and Youtube, as well as my own website:
https://ghostintranslation.bandcamp.com/
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