NeoPixel Breakout Board Install Guide

Table of contents

NeoPixel Breakout Board Install Guide

Overview

The NeoPixel Breakout Board receives 8 PWM signal lines via RJ45 from the PWM Card and powers up to eight 5 V NeoPixel-compatible LED strips (WS2812, SK6812). Voltage is regulated onboard from AC/DC/DCC input via the accessory power bus.

What’s Needed

Component	Purpose
NeoPixel Breakout Board	Distributes PWM signal and 5 V to each strip
PWM Card	Generates PWM signals for NeoPixel control
Network cable (CAT5/CAT6)	Connects PWM Card to Breakout Board (RJ45)
1–8 NeoPixel Strips (5 V)	LED output devices receiving signal and power
2-wire cable	Connects Accessory Power Bus to power input (J9)	(5 V type only)

Connection Diagram

flowchart LR
  subgraph Train Layout
    direction LR
    pwm[[PWM Card]]
    breakout[[NeoPixel <br>Breakout Board]]
    pwrbus("PWR BUS <br>(AC/DC/DCC)")
    pixel1["Pixel Strip 1"]
    pixel2-8["Pixel Strips 2...8"]
  end
  pwm -->|"Network Cable → J10"| breakout
  pwrbus -->|"2-wire Cable to J9"| breakout
  breakout --> |"3-wire → J1"| pixel1
  breakout --> |"3-wire → J2...J8"| pixel2-8

Connector Assignments

Label	Pins	Function
J1–J8	3-pin	Pixel headers (SIG/5V/GND)
J9	2-pin	Power input (AC/DC/DCC)
J10	RJ45	PWM input from PWM Card

Installation Steps

Set PWM Card selector for LINES 7/8 to PWM mode.
Connect PWM Card to NeoPixel Breakout Board using RJ45 network cable.
Connect PWR BUS (J9) to layout accessory power (AC, DC, or DCC).
Connect 1 or more NeoPixel strips to J1–J8 headers (SIG/5V/GND).

Note: Pixel signal lines are protected with 1kΩ resistors. Shared 5 V rail protected by SMAJ5.0A TVS + JK30 3A resettable fuse.
- Ensure PWM Card Line 8 is not set to 12 V if connected
- Pixel signal lines are protected with 1kΩ resistors
- Shared 5 V rail protected by SMAJ5.0A TVS + JK30 3A fuse

Status Indicators

LED1 ON = 5 V output active (power OK)

Testing & Troubleshooting

Cables & Connections
- Ensure the network cable between the PWM Card and NeoPixel Breakout Board is fully seated and oriented correctly.
- Verify accessory bus voltage and polarity at the board’s power connector.
- Confirm device wiring matches the board pinouts (signal, VDC+, GND).
Firmware & Diagnostics
- Use the LCC Configuration Monitor (JMRI), serial console, or other diagnostic tool to check that inputs register and outputs toggle as expected.

🧰 Troubleshooting Flow

Test	Check Point	Expected
Power LED	LED beside VR1	LED is ON
PWR BUS Voltage	J9 VDC+ → GND	> 12 VDC (AC, DC, or DCC)
5 VDC Regulator	J1–J4 VDC+ → GND	≈ 5.0 VDC
Device Activation	Output lines 1–8 via J10	Outputs switch on/off; inputs generate LCC Events

flowchart TD
  subgraph "NeoPixel Strip Test Flow" 
    direction LR
    Connect-Power("Connect supply power to <br>PWR BUS connector (J5)")   
    Connect-Card("Connect <br>Digital I/O Card")
    Connect-Device("Connect <br>output devices <br>(lamps, LEDs)<br>to connectors <br>(J1–J8)")
    Activate-Device("Activate strip <br>(via LCC Event)")
    Activate-Input-Line("Bypass NeoPixel Card: <br>Apply 5 V to each <br>input line (J6)")
    	
    LED-Q{"Is the Power LED ON?"}
    PWR-Q{"Measure input at PWR BUS (J9).<br><br>Is voltage >14 V?"}
    Device-On-Q{"Do connected strips <br>turn ON correctly?"}
    Input-Test-Q{"Does the <br>corresponding <br>strip turn ON?"}
    
    Success[["✅ Installation <br>Successful"]]
    
    Connect-Power --> LED-Q
    LED-Q -- "Yes, power LED is On" --> Connect-Card --> Connect-Device --> Activate-Device --> Device-On-Q
    LED-Q -- "No, power LED is Off" --> PWR-Q
    PWR-Q -- "Yes, valid input power" --> Bad-Board
    PWR-Q -- "No, invalid input power" --> Fix-PWR
    
    Fix-PWR["Check layout <br>power wiring, <br>power supply <br>voltage"]
    Fix-CDI["Verify NeoPixel card is good. <br>Check cards's <br>CDI configuration"]
    Fix-Device["Check strip <br>wiring, polarity,<br>or replace device"]
    Bad-Board["Likely bad <br>NeoPixel Breakout Board <br><br>Contact builder"]

    
    Device-On-Q -- "Yes, strip working" --> Success
    Device-On-Q -- "No, strip not working" -->   Activate-Input-Line --> Input-Test-Q
    Input-Test-Q -- "Yes, strip works without <br>NeoPixel Card" --> Fix-CDI
    Input-Test-Q -- "No, strip not working" -->  Bad-Board
  end

  %% Color styles
  classDef question fill:#d3d3d3,stroke:#333,stroke-width:2px,font-size:16px;
  classDef error fill:#FFA07A,stroke:#333,stroke-width:2px,font-size:16px;
  classDef success fill:#c6f6c6,stroke:#2c7a2c,stroke-width:2px,font-size:16px;
  classDef action fill:lightblue,stroke:#2c7a2c,stroke-width:2px,font-size:16px;

  class LED-Q,PWR-Q,Relay-Click-Q,Input-Test-Q,Device-On-Q question;
  class Fix-PWR,Fix-CDI,Fix-Device,Bad-Board error;
  class Connect-Power,Connect-Card,Connect-Device,Activate-Device,Activate-Input-Line action;
  class Success success;