Pico W PIO 4-Digit 7-Segment Example

Documentation-first repository for a Raspberry Pi Pico W / RP2040 project that drives a 4-digit 7-segment display using PIO-based multiplexing.

Features

• RP2040 PIO-assisted 7-segment multiplexing
• 4-digit decimal counter display (incrementing)
• UART serial banner output on startup
• Wiring and architecture docs included

Repository Layout

• src/main.cpp — original firmware logic (preserved)
• include/segment.pio.h — placeholder contract for PIO-generated header
• docs/wiring.md — wiring map, components, GPIO usage
• docs/architecture.md — code/module breakdown and data flow
• CMakeLists.txt — minimal documentation-oriented CMake scaffold

Hardware Components

• Raspberry Pi Pico / Pico W (RP2040)
• 4-digit 7-segment display (A, B, C, D, E, F, G, DP, DIG1..DIG4)
• Jumper wires
• (Recommended for real hardware) current-limiting resistors

Pin Mapping (Pico)

Signal	GPIO
A..DP	GP2..GP9
DIG1..DIG4	GP10..GP13
UART TX	GP0
UART RX	GP1

Run in Wokwi

1. Create/import a Raspberry Pi Pico project in Wokwi using Arduino community core.
2. Place src/main.cpp logic as the sketch source.
3. Use the provided diagram.json wiring (or mirror docs/wiring.md).
4. Start simulation and open Serial Monitor.
5. Expect startup message and incrementing 4-digit output.

Run on Real Hardware

1. Open project with Arduino IDE / Arduino CLI using an RP2040 Arduino core.
2. Ensure your PIO helper/header (segment.pio.h) is present exactly as expected by the code.
3. Select board: Raspberry Pi Pico W.
4. Build and flash.
5. Connect display per docs/wiring.md and verify counting output.

Wi-Fi Notes

• This firmware does not use Wi-Fi.
• If you add Wi-Fi later, keep credentials outside source control (e.g., local config header or build-time defines).

Behavior Constraints

This repository intentionally preserves the provided main firmware behavior and focuses on structure + documentation.