# RP2040 MIDI Tracker

A simple MIDI step sequencer using a Raspberry Pi Pico, an OLED display, a rotary encoder, and an 8x8 NeoPixel matrix.

## Connections & Wiring

Properly wiring the components is crucial, especially for power.

### Power

The project is best powered in two parts:
1.  **Raspberry Pi Pico**: Power the Pico via its Micro-USB port from a computer or a USB wall adapter.
2.  **NeoPixel 8x8 Matrix**: This component is power-hungry and **requires a separate, external 5V power supply**. A power supply capable of delivering at least 2A is recommended.

> **WARNING**: Do NOT power the NeoPixel matrix from the Pico's 3.3V or VBUS pins. Doing so can draw too much current and damage your Pico and/or the host computer's USB port.

### Component Wiring

Make sure to establish a **common ground** by connecting the ground from your external 5V power supply to one of the GND pins on the Pico.

| Component | Pico Pin | Description |
| :--- | :--- | :--- |
| **SSD1306 OLED** | | |
| VCC | 3V3 (OUT) (Pin 36) | 3.3V Power |
| GND | GND (Pin 38) | Ground |
| SDA | GP4 (Pin 6) | I2C Data |
| SCL | GP5 (Pin 7) | I2C Clock |
| **Rotary Encoder** | | |
| + (VCC) | 3V3 (OUT) (Pin 36) | 3.3V Power |
| GND | GND (Pin 33) | Ground |
| CLK | GP12 (Pin 16) | Encoder Clock |
| DT | GP13 (Pin 17) | Encoder Data |
| SW | GP14 (Pin 19) | Encoder Switch |
| **WS2812B 8x8 Matrix**| | |
| DIN (Data In) | GP16 (Pin 21) | NeoPixel Data |
| 5V / VCC | External 5V Supply `+` | **External 5V Power** |
| GND | External 5V Supply `-` | **External Power Ground** |
| | GND (Pin 18) | **Common Ground with Pico** |

Once everything is wired up, you can upload the code and your tracker should be ready to go!