Example to control GPIO pins though command interface.

GPIO Service Application

A NetBurner embedded system application for controlling General Purpose I/O (GPIO) pins through a command-line interface.

Note: For platform-specific GPIO examples and advanced usage, refer to the "Example Applications > Platform Specific" section in the NetBurner Documentation.

Overview

This application provides a serial command interface for configuring and controlling GPIO signals on NetBurner modules. It sets up a command parser on the default serial port, allowing users to interact with GPIO pins in real-time through simple text commands.

Features

Real-time GPIO pin control via serial terminal
Support for multiple NetBurner platforms with automatic connector detection
Command history with navigation (Ctrl+D, Ctrl+U, Ctrl+R)
Interactive help system
Web server integration for network diagnostics

Supported Operations

The application supports the following GPIO operations:

HI - Set a pin to logic high (3.3V/5V)
LO - Set a pin to logic low (0V)
TGL - Toggle a pin's current state
OUT - Configure a pin as an output
IN - Configure a pin as an input (high impedance)
RD - Read the current state of a pin
HELP - Display available commands

Platform Support

The application automatically adapts to different NetBurner platforms:

MODM7AE70: Uses P2 connector with PinIO::PIN_FN_OUT function
NANO54415 & SB800EX: Uses main connector (Pins) with PIN_GPIO function
Other platforms: Uses J2 connector with PIN_GPIO function

Hardware Requirements

NetBurner development module
Serial terminal connection (debug/status port)
GPIO-capable pins on the target connector

Warning: Not all pins on every NetBurner device can function as GPIO. Consult your specific device datasheet for GPIO capabilities and pin assignments.

Software Requirements

NetBurner NNDK (NetBurner Network Development Kit)
MTTTY or compatible serial terminal software
Network connection for web server functionality (optional)

Building and Installation

Build the project using the NetBurner development environment
Load the compiled application onto your NetBurner device
Connect to the device's debug/status port using a serial terminal
The application will automatically start and display the command prompt

Usage Examples

Basic Pin Control

> HI 5          # Set pin 5 high
P2[5]_out: 1
 
> LO 3          # Set pin 3 low  
P2[3]_out: 0
 
> TGL 7         # Toggle pin 7
P2[7]_out: 1

Pin Configuration

> OUT 2         # Configure pin 2 as output
> IN 4          # Configure pin 4 as input
> RD 4          # Read pin 4 state
P2[4]_in: 0

Interactive Features

Press Enter on empty line to repeat last command
Use Ctrl+D to navigate to previous command in history
Use Ctrl+U to navigate to next command in history
Use Ctrl+R to recall and execute previous command
Use Backspace to edit current command

Command Reference

Command	Syntax	Description
HI	`HI <pin>`	Set specified pin to logic high
LO	`LO <pin>`	Set specified pin to logic low
TGL	`TGL <pin>`	Toggle pin state (repeatable with Enter)
OUT	`OUT <pin>`	Configure pin as output driver
IN	`IN <pin>`	Configure pin as high-impedance input
RD	`RD <pin>`	Read pin state (repeatable with Enter)
HELP	`HELP`	Display command help

Application Architecture

Key Components

Command Parser: Processes serial input and maps to function calls
GPIO Abstraction: Platform-independent pin control interface
Command History: Circular buffer storing recent commands
Network Stack: Built-in web server for diagnostics

Memory Usage

Command buffers: 5 buffers x 80 characters each
Read buffer: 256 bytes
Minimal stack usage for embedded operation

Network Features

The application includes built-in network functionality:

HTTP web server on port 80
DHCP client for automatic IP assignment
System diagnostics accessible via web interface
5-second network initialization timeout

Error Handling

Graceful handling of invalid commands with "Unrecognized command" message
Parameter validation for pin numbers
Safe defaults for missing parameters
Non-blocking serial input processing

Development Notes

All commands are case-insensitive (automatically converted to uppercase)
Pin numbers are parsed as decimal integers
The application runs in an infinite loop with 1-second intervals
Platform-specific macros handle connector and function differences