1-Wire

Supported Platforms: MOD5441x, NANO54415

1-Wire DS2401 Silicon Serial Number Reader

Overview

This NetBurner application demonstrates how to interface with a DS2401 Silicon Serial Number chip using the 1-Wire protocol on MCF5441X-based platforms. The application continuously detects and reads the unique 64-bit registration number from connected DS2401 devices.

Supported Platforms

• MOD5441X - Uses pin J2[37] for 1-Wire data line
• NANO54415 - Uses pin 12 for 1-Wire data line

Hardware Requirements

• NetBurner MOD5441X or NANO54415 module
• DS2401 Silicon Serial Number chip
• Pull-up resistor (4.7k ohm recommended) between data line and VCC
• Power supply connections (VCC and GND)

Hardware Connections

MOD5441X Platform

• 1-Wire Data: J2[37] (configured as OW_DAT function)
• Power: Connect DS2401 VCC to 3.3V or 5V
• Ground: Connect DS2401 GND to system ground
• Pull-up: 4.7k ohm resistor between data line and VCC

NANO54415 Platform

• 1-Wire Data: Pin 12 (configured as OW_DAT function)
• Power: Connect DS2401 VCC to 3.3V or 5V
• Ground: Connect DS2401 GND to system ground
• Pull-up: 4.7k ohm resistor between data line and VCC

Application Functionality

Main Features

1. 1-Wire Protocol Implementation: Custom 1-Wire peripheral driver
2. Device Detection: Automatic detection of DS2401 devices on the bus
3. Serial Number Reading: Reads complete 64-bit registration number
4. Continuous Monitoring: Polls for devices every 5 seconds
5. Formatted Output: Displays family code, serial number, and CRC

Program Flow

1. Initialization
   • Initialize network stack with init()
   • Enable system diagnostics
   • Wait for network activity (up to 5 seconds)
   • Initialize 1-Wire module with OWInit()
   • Configure platform-specific pin functions
2. Main Loop (repeats every 5 seconds)
   • Detect devices on 1-Wire bus using OWDetectDevices()
   • If device found:
     • Send Read ROM command (0x33) to DS2401
     • Read 8 bytes of registration data
     • Parse and display formatted output
   • If no device found:
     • Display "Device not detected" message

Output Format

When a DS2401 is detected, the application displays:

- - - - - - Device detected - - - - - -
Family Code: 0x01
Hex Serial Number: 12 34 56 78 9A BC
CRC Code: 0xDE

DS2401 Registration Number Structure

The 64-bit registration number consists of:

• Byte 0: Family Code (0x01 for DS2401)
• Bytes 1-6: 48-bit unique serial number
• Byte 7: 8-bit CRC checksum

Key Components

Core Functions

• **OWInit()**: Initializes the 1-Wire peripheral module
• **OWDetectDevices()**: Scans bus for connected 1-Wire devices
• **OWWrite()**: Sends data to 1-Wire device
• **OWRead()**: Receives data from 1-Wire device
• **OWDone()**: Checks if 1-Wire operation is complete

Semaphore Usage

The application uses an OS semaphore (OS_SEM busSem) to synchronize 1-Wire read operations, ensuring data integrity and proper timing.

Building and Deployment

Prerequisites

• NetBurner Development Kit installed
• Target platform environment variables set

Troubleshooting

Common Issues

1. **"Device not detected" message**
   • Check physical connections
   • Verify pull-up resistor is installed (4.7k ohm)
   • Ensure DS2401 is powered correctly
   • Confirm correct pin assignment for platform
2. Build errors
   • Verify PLATFORM is set correctly (MOD5441X or NANO54415)
   • Check that NNDK_ROOT environment variable is set
   • Ensure all source files are present
3. Invalid serial number readings
   • Check data line signal integrity
   • Verify timing requirements are met
   • Ensure only one DS2401 device on bus for this example

Debug Output

The application includes diagnostic output showing:

• Application startup confirmation
• Device detection status
• Complete registration number breakdown
• Timing of detection attempts

Technical Notes

1-Wire Protocol Details

• Single data line for bidirectional communication
• Master-slave architecture (NetBurner as master)
• Time-slot based communication protocol
• Requires external pull-up resistor

DS2401 Specifications

• 64-bit lasered ROM with unique serial number
• Operating voltage: 2.8V to 6.0V
• Operating temperature: -40C to +85C
• Single-contact 1-Wire interface

Application Use Cases

This example demonstrates fundamental concepts applicable to:

• Asset tracking and identification
• Serial number logging systems
• Device authentication
• Inventory management
• Temperature sensor networks (with protocol modifications)

Related Examples

For additional 1-Wire functionality, consider exploring:

• Multi-device 1-Wire networks
• Temperature sensors (DS18B20)
• 1-Wire memory devices
• Advanced search algorithms for device enumeration