Sdvx proto

controller_subtests

Breadboard prototyping tests for a custom Sound Voltex (SDVX) controller built on the Raspberry Pi Pico 2 H (RP2350).

Each subfolder is a self-contained test with its own CMakeLists.txt and main.c.

Project Structure

controller_subtests/
├── CMakeLists.txt          ← top-level, registers all subtests
├── pico_sdk_import.cmake
├── serial_monitor.py       ← Python serial monitor for debugging
├── mx_switch_test/
│   ├── CMakeLists.txt
│   └── main.c              ← Cherry MX Brown button + onboard LED test
└── encoder_test/
    ├── CMakeLists.txt
    └── main.c              ← Bourns PEC11R rotary encoder test

Hardware

Subtest: mx_switch_test

Tests a single Cherry MX Brown switch on GPIO 0. Jumper wires are soldered directly to the two switch pins. Toggles the onboard LED on press/release and prints state over USB serial.

Wiring:

Switch Pin 1  → GPIO 0  (pin 1)
Switch Pin 2  → GND

Note: Uses the Pico's internal pull-up — no external resistor needed. Pin reads HIGH at rest and LOW when pressed.

Subtest: encoder_test

Tests a Bourns PEC11R rotary encoder — quadrature rotation via interrupt and push switch via polling.

Wiring:

ENC A    → GPIO 10  (pin 14)
ENC C    → GND
ENC B    → GPIO 11  (pin 15)
SW pin 1 → GPIO 12  (pin 16)
SW pin 2 → GND

How it works:

• An interrupt fires on every rising/falling edge of channel A
• Inside the ISR, A and B are compared — if they differ, direction is CW (+1), if same, direction is CCW (-1)
• The push switch is polled in the main loop with debounce

Building

Requires the Raspberry Pi Pico SDK. Set PICO_SDK_PATH in your environment or let CLion handle it via the CMake Environment field.

mkdir cmake-build-debug && cd cmake-build-debug
cmake ..
make

Each subtest outputs its own .uf2 into its own subfolder:

cmake-build-debug/
├── mx_switch_test/
│   └── mx_switch_test.uf2
└── encoder_test/
    └── encoder_test.uf2

To flash:

1. Hold BOOTSEL on the Pico while plugging in USB
2. It mounts as a drive called RP2350
3. Drag and drop the .uf2 onto the RP2350 drive

Serial Monitor

Use the included serial_monitor.py to watch output over USB serial.

Requirements:

pip install pyserial

Run:

python serial_monitor.py

Defaults to COM3 at 115200 baud. Edit PORT at the top of the script if your Pico is on a different port (check Device Manager → Ports (COM & LPT)).

CLion Serial Monitor (alternative)

CLion has a built-in serial monitor under Tools → Serial Monitor.

Settings that must be enabled for it to work with the Pico:

• Enable HW Flow Control — on
• Local Echo — on
• DTR — enabled (this is what actually triggers the Pico to send output)

Without DTR enabled, the monitor connects but receives nothing.

Notes

• Both encoder A and B pins use the Pico's internal pull-ups — no external resistors needed for basic testing
• For final PCB design, add a hardware filter (10KΩ + 0.01µF on each channel) per the PEC11R datasheet recommendation to reduce contact bounce at higher RPM
• The encoder's position counter is unbounded (volatile int) — for HID use, report the delta each frame rather than an absolute value