XFM2UI
XFM2UI is an Arduino menu driven user interface for all XFM2 parameters. It is based on Teensy 4.0 microcontroller it uses a single clickable rotary encoder as input, and displays the menu and settings on an SSD1306 OLED display.
XFM2 is a project by Rene that implements a very full featured 2-voice FM synthesizer on top of the CMOD A7 FPGA. You can find his project here https://www.futur3soundz.com/
Hardware
You will likely need to have built one of the XFM2 synths prior to taking interest, so please refer to Rene's blog above for instructions on aquiring the synth.
18 digital pins available for the connection of mapped analog or digital controls for additional direct control.
Build of Materials
The current XFM2UI hardware consists of:
- PJRC Teensy 4.0 (however almost any arduino compatible board will work)
- A clickable rotary encoder
- Breadboard, protoboard, or other suitable prototyping platform
- Adafruit SSD1306 OLED 128x64 pixel display
Hardware Build Instructions
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Completed XFM2 module as per the instructions found on the XFM2 blog (not covered here).
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Solder header pins to connect Teensy to breadboard
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Connect middle encoder pin to ground
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Connect two other encoder pins to digital pins 3 and 4
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Connect encoder button pin to ground
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Connect other encoder button pin to digial pin 5
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Connect SSD1306 VCC to 5V VIN
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Connect SSD1306 GND to ground
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Connect SSD1306 SCL to pin 19
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Connect SSD1306 SDA to pin 18
Software
The basis of the interface is menu driven concept to permit the modification of the parameters within the XFM2 code. These parameters are numbered and named and each refers to a value that will change the personality of the synthesizer in real-time.
The menu system is based on the Arduino Menu library (https://github.com/neu-rah/ArduinoMenu).
The menus are implemented using:
- basic fields (0-255 integer ranges in whole number increments)
- toggles to switch between options that have less than 10 options
- binary calculations for the bitwise fields (not done yet)
Contributing
Pull requests are always welcome and encouraged. I am not an experienced software developer and new to the Arduino platform so I'm learning through this project.
Items on the list of nice to haves are:
- Reading XFM2 and setting the menu's initial parameter values on startup
- Creating the ability to save and recall sets of parameters (programs) in the XFM2
- Adding additional configurable analog controls (buttons, sliders, faders, etc) to adjust user-mapped parameters.
Collaboration
There is a slack channel created for active discussion and development for the software. https://join.slack.com/t/xfm2/shared_invite/zt-dmrs50h3-34WvYiWgPBWruNXSXLYgBg
List of Priorities
- UART bi-directional data communication between the XFM2UI and XMF2
- Basic parameter changes
- Preset recall features (load, save, share)
- Map additional controls (pots, encoders, faders, etc)
- Web-based UI (using wireless adapter potentially)