Card Communications Configuration Guide

Table of contents

1. Card Communications Configuration Guide
   1. Introduction
   2. Key Configuration Elements
   3. I2C Addressing Overview
   4. I2C Address Assignments by Card Type
      1. Final Notes

Introduction

The LCC Fusion Project uses the I2C protocol to facilitate communication between its Node and I/O cards. Each I/O card is assigned a bus (A or B) and an I2C address, both of which must be configured correctly to avoid conflicts.

Key Configuration Elements

• Communication Bus Selection: Cards are assigned to either Bus A or Bus B, corresponding to processor hardware buses 0 and 1.

  Some cards only support Communication Bus A and cannot be reassigned.

• I2C Address Configuration: Each card has a unique I2C address, determined by its onboard address selectors.

  Each card within an LCC Fusion Node Cluster must have a unique bus and address combination to prevent conflicts.

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I2C Addressing Overview

The maximum number of addressable cards per LCC Fusion Node Cluster is as follows:

Address Group	Max Addressable Cards
1	16 (8 per Communication Bus)
2	16 (8 per Communication Bus)
3	16 (8 per Communication Bus)
4	16 (8 per Communication Bus)
5	16 (8 per Communication Bus)
6	48 (uses Communication Bus A only)
7	4 (uses Communication Bus A only)

Note: Address Group 6 is limited to Communication Bus A and does not support Bus B.

Each I2C-enabled IC or ESP32-based card has a specific address range. Since multiple cards may use the same IC, each bus and address pairing must be unique within the cluster.

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I2C Address Assignments by Card Type

Address Group	Card Name	I2C IC	I2C Address Range (per bus)	Bus Restrictions
1	DCC Card	ESP32	0x10 - 0x17	Bus A or B
2	Output Card	MCP23017	0x20 - 0x27	Bus A or B
2	BOD Card	MCP23017	0x20 - 0x27	Bus A or B
2	Button Card	MCP23017	0x20 - 0x27	Bus A or B
2	IO Card	MCP23017	0x20 - 0x27	Bus A or B
2	POD Card	MCP23017	0x20 - 0x27	Bus A or B
2	Stepper Motor Card	MCP23017	0x20 - 0x27	Bus A or B
2	Turnout Card	MCP23017	0x20 - 0x27	Bus A or B
3	Sound Card	ESP32	0x30 - 0x37	Bus A or B
4.1	PWM Card	PCA9685	0x40 - 0x47	Bus A or B
4.2	Power-CAN (0.96” OLED Monitor)	ADS1115	0x48 - 0x4B	Bus A only
5	UOD Card	ESP32	0x50 - 0x57	Bus A or B
6	NFC Tag Reader Card	MFRC523	0x08 - 0x3F	Bus A only

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Final Notes

• Cards within the same Address Group must not share the same I2C address on the same bus.
• dCards in Address Groups 4.2 and 6 are restricted to Bus A only.
• This guide serves as a reference to prevent address conflicts as new I2C-based cards are added.