GPIO

Overview

FREE-WILi includes a GPIO pin header for interacting with digital protocols. This GPIO header is flexible, allowing varying voltage levels and IO direction control. The GPIO system supports SPI, I2C, UART, and general-purpose digital I/O operations.

FREE-WILi Pinout.

FREE-WILi GPIO Header

GPIO System Architecture

The GPIO pins are routed through level-shifting buffers and an iCE40UP5K FPGA before connecting to the RP2040 main processor. This architecture enables real-time operations such as the logic analyzer functionality while maintaining protocol compatibility.

Quick Start

1. Set I/O Voltage Level: Connect a jumper between pins 2-4 (5V) or 4-6 (3.3V)
   • Pin 4 MUST have voltage for GPIO to function
2. Configure Pin Directions: Use the GPIO panel in the GUI or settings menu via serial console
3. Select Protocol: Access SPI, I2C, or UART functionality through the main console application

GPIO Documentation Sections

• Pinout & Electrical Specifications - Pin descriptions, voltage levels, and electrical characteristics
• Protocol Configuration - SPI, I2C, and UART setup and specifications
• Common Issues & Troubleshooting - Solutions to frequent problems

Related Documentation

• Logic Analyzer - Real-time GPIO monitoring and analysis
• WASM Scripting - Advanced GPIO control through WebAssembly
• ZoomIO Scripting - Nanosecond-precision GPIO timing
• Settings Menu - GPIO direction and protocol configuration