Block Breakout Board Assembly Guide

Table of contents

1. Block Breakout Board Assembly Guide
   1. Introduction
      1. System Overview:
   2. Terminology
   3. Assembly and Component Placement*
   4. Tools Required
   5. Safety Precautions
   6. Testing and Verification
      1. Visual Inspection
      2. Functional Testing
   7. Troubleshooting
   8. Appendences
      1. Specifications
      2. How It Works
      3. Connections
      4. References

Introduction

The Block Breakout Board, in combination with the BOD Card and the Node Card, is used to simplify wiring for monitoring track blocks. The Block Breakout Board connects to track rails to facilitate the detection of trains (both locomotives and rolling stock) within specific track blocks. The BOD Card provides status updates via its GPIO pins to the LCC Fusion Node Card. The LCC Fusion Node Card firmware processes these updates to generate LCC events, which can then be used by other systems, such as the PWM Card, for tasks like managing signal operations based on track occupancy.

flowchart LR; 
can["CAN Network"];
subgraph layout ["Train Layout"];
  direction LR;
  bod["BOD/BSD Cards (16x)"]
  nodecard[Node Card]; 
  track["Track Block (4x)"] 
  bb[Block Breakout Board];

  track --> bb;
  bb -->|"Current <br/> (yes/no)"| bod;
  bod -->|"GPIO Output <br/> High/Low"| nodecard;
  nodecard -->|"LCC Event <br/> (occupied/unoccupied)"| can;
end;
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class bb lSalmonStyle;
classDef lightGrayStyle fill:#d3d3d3,stroke:#333,stroke-width:2px,font-size:24px;
class layout lightGrayStyle; 

System Overview:

The Block Breakout Board works alongside the LCC Fusion Node Card to simplify wiring and streamline monitoring for multiple track blocks within a layout. When integrated with the BOD Card, the Block Breakout Board monitors track blocks for the presence of locomotives or rolling stock. The BOD Card detects the current flow through the tracks, indicating whether a block is occupied or unoccupied. This information is relayed to the LCC Fusion Node Card, which processes the signals via GPIO pins and generates LCC Events.

These events can be utilized by other LCC devices, such as signal control systems, to automate layout responses based on block occupancy.

Diagram Overview:

The diagram below shows how the Block Breakout Board interacts with the BOD Card, the track blocks, and the LCC Fusion Node Card to monitor both occupancy and voltage conditions.

Control Flow:

• The Block Breakout Board interfaces with the track rails to monitor the current flow.
• The BOD Card detects whether current is flowing (indicating occupancy) and outputs GPIO signals to the Node Card.
• The Node Card processes the input and generates LCC Events to update other systems on whether the block is occupied or unoccupied.

flowchart TD; 
subgraph layout["Train Layout"];
	subgraph layoutbus["Track Bus"];
	  busA["TRACK BUS A"];
  	busB["TRACK BUS B"];
  end;
  direction LR;
  bb[Block<br>Breakout Board];
  bod["BOD / BSD Cards (16x)"];
  railA["RAIL A<br>(non-gapped)"];
  railB["Rail B (4x)<br>(gapped,isolated)"];

  nodeCard[Node Card];
  loco["Locomotive Motor"];
	
  busA --> railA --> loco --> |"current"|railB;
  railB --> |"current"|bb --> |"current"|bod --> |"current"|bb --> busB;
  bod --> nodeCard;   
end;
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class bb lSalmonStyle;
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class layout lightGrayStyle;
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class layoutbus lightblueStyle;

Terminology

• Cleaning PCB

• Component

• LCC Fusion Breakout Boards

• LCC Fusion Cards

• lcc_fusion_node_card - not defined

• LCC Fusion Project

• Network Cable

• Track Bus

For other terms, please refer to the full Terminology Guide.

Assembly and Component Placement*

This section combines both the component specifications and the assembly instructions to ensure a smooth assembly process. Below is a comprehensive list of components, their placement on the PCB, and orientation details to assist you during assembly.

Note: Components R1–R4, D1–D4, and jumpers JP1–JP4 are only required when implementing the optional Block Power Control with Trickle Detection Support.
This feature allows occupancy detection to remain active even when Track Block Rail A is turned off, by injecting a small current into the block via a 10kΩ resistor (R1–R4) and Schottky diode (D1–D4). Each jumper (JP1–JP4) enables or disables the trickle path for its respective block.

High-Level Steps for Assembly:

• PCB for the card can be ordered from any PCB fabricator using these Gerber Files.
• Clean PCB with alcohol to remove residue. See Cleaning_PCB for details.
• See also: Soldering Tips
• PCB Components - listing of components used for PCB assembly
• PCB Parts - listing of parts used for PCB assembly

Below is a list of the PCB components used for this card (see diagram before reference):

1. Use of 2-pin JST XH pre-wired plugs soldered to track rail drop wires makes for easy wiring and fast connect/disconnect.
2. Use of 2-position Spring Terminals (2.54mm) allow for rail drop wires to be connected directly pulling back a spring lever. These connectors can be ordered as 2-Position or assembled into a set of 2-Positions.
3. Make sure this track rail has isolators creating blocks, where each block is wired to one or more of Block Breakout Boards and a BOD Card.

Component Identifier	Count	Type	Value	Package	Purpose	Orientation
Capacitors
C1	1	Capacitor-Ceramic	0.1uF	1206 X7R	DCC Bus Snubber (RC circuit)	None
Connectors
J1	1	JST XH Socket or 2-Position Spring Terminal Connector	4P, 2.54mm	PTH, vertical or horizontal	Connectors to track Block Rails (isolated block Rail B).	Position connection outward
J2	1	JST XH Socket or 2-Position Spring Terminal Connector	2P, 2.54mm	PTH, vertical or horizontal	Connector to layout’s Track Bus A & B wires	Position connection outward
J3	1	RJ45 Socket	8P8C	PTH	Network cable (CAT5/6) connection from BOD Card.	Fits only one way
J4	1	Card Edge Connector	-	-	For use with Test Breakout Board.	None
Selectors
JP1-JP4	4	Male Header	2P, 2.54mm	n/a	Use Jumper Cap to boost power to the coils by using (2) 2200uF capacitors.	None
SH1-SH4	4	Jumper Cap (Shunt)	2.54mm	-	Used with JP1-JP4	None
Diodes
D1-D4	4	Schottky Diode	SS310	SMA	Reverse current protection for trickle path preventing unwanted back feed between blocks or into the Track Bus.	Cathode end has a white line and positioned towards PCB left edge
Resistors
R1-R4	4	Resistor	10k Ω	1206 SMD	Current limiting for trickle path	None
R5	1	Resistor	120 Ω	1206 SMD	DCC Bus Snubber (RC circuit)	None
Selectors
JP1	1	Male Header	2-Pin, 2.54mm	PTH	Used to enable DCC Bus Snubber (one required at end of bus)	None
SH1	1	Jumper Cap	2.54mm	N/A	Used with DCC Bus Snubber selection. Recommend tall caps for ease of use.	None

Tools Required

List of recommended tools.

Safety Precautions

• See Safety Precautions.

Testing and Verification

Visual Inspection

1. Initial Check: Examine the board for any obvious issues like missing components, solder bridges, or components that are misaligned or not fully seated.
2. Solder Joint Inspection: Use a magnifying glass or a microscope to inspect solder joints. Look for cold solder joints, insufficient or excessive solder, or any shorts between pads.
3. Use an Digital Multimeter (DMM) to test for continuity between:
   • RJ45 socket pins (2, 4, 6, 8) and the 4 block connectors (J1, J2).
   • RJ45 socket pins (1, 3, 5, 7) and the Track Bus B connector (J3)

Functional Testing

Refer to BOD Card for details on testing the Block Breakout Board with the BOD Card.

Troubleshooting

• See I2C Trouble Shooting.

Appendences

Specifications

Specifications for the Block Breakout Board include:

Characteristic	Value
Max Track Blocks	4
Max Track Current	2750 mA1, 2

1. Block Breakout Board uses 54mmil traces that support up to 3000 mA.
2. A CAT6 network cable with 23 awg wiring is limited to <1000 mA.

How It Works

For track block occupancy detection details, refer to the BOD Card How it Works](/LccFusionProject/bod-card-assembly-guide/) section.

Connections

The purpose of the Block Breakout Board and its connectors is to facilitate quick and easy connections between the BOD Card and the track rails. For setups with multiple distant blocks, breakout boards can be daisy-chained together, or a network cable with a splitter can be used to provide multiple connections efficiently.

Component Designator	Connector Label	Connector Type	Connection Number	Description
J1	TRACK BLOCKS	JST XH, Spring Terminal	1, 2, 3, 4	Connection to insulated block rails
J2	TRACK BUS	JST XH, Spring Terminal	A, B	Connection to layout Track Bus A and B wires (completes connection from track to bus)
J3	BOD CARD	RJ45 Socket	1/2, 3/4, 5/6, 7/8	Each pin pair connects to blocks 1 thru 4. Cable to BOD Card for detection of trains, and/or cable to BLVD Card for low voltage detection caused by shorts or faulty connections.
J4	TEST BOARD CONNECTOR	Card Edge	1, 2, 3, 4, COM	Connection to Test Board for connections to the test board track

References

• Preparing a PCB for Soldering
• Solder Tips