BSD Card Quickstart 

Table of contents
  1. BSD Card Quickstart
    1. Overview
    2. Quickstart Checklist
    3. What You Need
    4. Step 1 – Install the Node Card and BSD Card
    5. Step 2 — Connect the BSD Card to the Block Breakout Board
    6. Step 3 — Configure the BSD Card
    7. Step 4 — Test and Verification
      1. Occupancy Detection
      2. Short Detection
    8. Related Documentation

Overview

This Quickstart walks you through:

  1. installing the BSD Card and its Block Breakout Board
  2. wiring a single gapped block
  3. applying layout power
  4. validating the end-to-end event path, confirming that block-detection signals from the BSD Card appear as the expected Occupied/Clear LCC events on the CAN bus

The diagram below shows the flow of detection and communication through the system:

Track → Block Breakout Board → BSD Card → Node Bus Hub → Node Card → CAN Bus

Quickstart Checklist

Do these steps in order:

  1. Insert Cards
    • Install an ESP32-S2 DevKit-C Module with installed firmware onto the BSD Card
    • Install the Node Card and BSD Card into a Node Bus Hub.
    • Power the Node Card.
  2. Connect to the Breakout Board
    • Set the BSD Card’s COMM BUS (A/B) and COMM ADDR (1–7).
    • Connect the BSD Card’s J1 or J2 to the Breakout Board’s BSD/BSD CARDS port.
    • Optionally install a SSD1306/1309 LCD Display (J3)
  3. Wire Track and Blocks
    • Connect gapped Rail B for Blocks 1–4 to TRACK BLOCKS – GAPPED RAIL B (J1).
    • Connect layout Track Bus B to TRACK BUS B (J2).
    • If both rails are gapped:
      • Set JP1–JP4 jumpers
      • Connect layout Track Bus A to TRACK BUS A (J2).
  4. Configure CDI
    • Match CDI COMM Bus + COMM Addr to the card’s switches.
    • Fill in Card Description and Block Descriptions.
    • Adjust Debounce only if needed.
    • Set the Initial Power-On State.
  5. Verify Detection
    • Place a locomotive or resistor wheelset on the block.
    • Confirm: LED → Occupied Event → Clear Event after removal.

What You Need

  • A LCC Fusion Node Card powered and visible in the CDI Configuration Tool
  • A ESP32-S2 DevKit-C Module with the BSD Card Firmware installed
  • LCC Fusion BSD Card
  • LCC Fusion Block Breakout Board
  • Wires
    • Card ↔ Breakout Board: Use CAT6 network cable
      • Safely handles short-duration block currents as a locomotive passes.
      • For higher sustained current, use 18–20 AWG with two RJ45 → Spring Terminal Boards.
      • For lowest voltage drop, keep the CAT6 run short by placing the BSD Card near the blocks:
        6× Node Bus Hub /w Node Card → (long CAT6) → 2× Node Bus Hub /w BSD Card → (short CAT6) → Block Breakout Board
    • Block Drop Wires: Match the gauge used between the BSD Card and the Breakout Board (e.g., 23 AWG when using CAT6).
  • Access to the layout Track Bus A/B wires
  • Access to the layout track gapped blocks
  • A locomotive or resistor wheelset

Step 1 – Install the Node Card and BSD Card

  1. Install a tested Node Card into a test Node Bus Hub.
  2. Install the ESP32 Module into a tested BSD Card
  3. Install the tested BSD Card into the same Node Bus Hub.
  4. Power the Node Card.

Step 2 — Connect the BSD Card to the Block Breakout Board

  1. On the BSD Card
    1. Configure communications to a unique setting across cards:
      • Set the COMM BUS to either Bus A or Bus B (JP1/JP2).
      • Set the COMM ADDR to 1 through 7 by sliding the switches (SW1)
    2. Connect a network cable to BLOCK BREAKOUT BOARD BLOCKS 1–4 (J1)
  2. On the Block Breakout Board
    1. Ensure the layout track bus is powered off.
    2. Connect the other end of the network cable to the BSD/BSD CARDS connector (J2).
      • This carries the gapped Rail B detection current to/from the BSD Card.
    3. If any of the blocks are at the end of the track bus, set the DCC BUS SNUBBER using a jumper.
    4. If a block has both rails gapped, then:
      1. Set the corresponding JP1–JP4 jumper(s) to enable that block’s current detection, and
      2. Connect TRACK BUS A (J2) to the layout’s Track Bus A.

Step 3 — Configure the BSD Card

  1. Open the CDI Configuration Tool.
  2. Locate the appropriate LCC Node.

  3. Open the BSD Card segment.

  4. Update the Card Description field
    • Use a meaningful name that tells you what this card is watching, for example:
      • Mainline Zone 54 Blocks
      • Staging Yard A Blocks
    • This makes it much easier to identify the card later when you have multiple BSD Cards on the layout.
  5. Update each Block / Line Description
    • For each block input on the card, fill in a short description that ties it back to the layout, for example:
      • Zone 54, Block 1
      • Zone 54, Block 2 (East Siding)
    • Use a consistent naming pattern so wiring, CDI, and documentation all line up.
  6. Set the valid range for Occupancy, where currecnt levels
    • below the range result in detection
    • above the range result in a short event and circuit being disconnected
  7. Set the Debounce value
    • Start with the default debounce time.
    • If testing shows noisy occupancy (flicker, rapid changes), increase the debounce value slightly.
    • If detection feels too sluggish, you can reduce it—but only after confirming the track and wiring are clean.
  8. Set the Initial Power-On State
    • Choose how each block should report when the layout first powers up:
      • Some operations prefer all blocks to come up as Clear until detection says otherwise.
      • Others may want a more conservative behavior, depending on operating practices and safety preferences.
    • Actual operations on your layout will determine the best choice here.
  9. Use the default event IDs unless you have a specific event mapping strategy in place.

Step 4 — Test and Verification

Occupancy Detection

Place a locomotive or resistor wheelset on your test block.

Expected behavior:

  • The block’s OCCUPIED LED on the BSD Card turns on.
  • The Node Card generates a Occupied (ON) event.
  • The CDI tool displays the event on the CAN bus.

Remove the locomotive or resistor wheelset.

Expected behavior:

  • The block OCCUPIED LED turns off.
  • A Occupied (OFF) event is generated.

Short Detection

Short the track

Expected behavior:

  • The block’s SHORTED LED on the BSD Card turns on.
  • The Node Card generates a Short (ON) event.
  • The CDI tool displays the event on the CAN bus.
  • Current in block turns off while shorted

Remove the short

Expected behavior:

  • The block SHORTED LED turns off.
  • A Short (OFF) event is generated.

This confirms the complete detection / short chain: Track → Block Breakout Board → BSD Card → CAN → Node Card → CDI

Last updated on: January 12, 2026 © 2026 Pat Fleming