SuperMini IO Status Shield Assembly Guide

Table of contents
  1. SuperMini IO Status Shield Assembly Guide
    1. Introduction
    2. Assembly and Component Placement
    3. Tools Required
    4. Safety Precautions
    5. Testing and Verification
      1. PCB Configuration
      2. Visual Inspection
      3. Connectivity Testing
      4. Power-Up Tests
      5. Functional Testing
    6. Troubleshooting
    7. Appendences
      1. Specifications
      2. How It Works
      3. Design Notes
      4. Protection
      5. References

Introduction

In conjunction with the LCC Fusion Project Quad-Node Card, the SuperMini IO Status Shield provides status for the (8) I/O lines. The Shield is typically used initial testing and deployments as a means of verifying whether or not the I/O lines are producing an output or input signal. The Shield used is optional and must be plugged into one of the Quad-Node Card sockets, with a SuperMini ESP32-S3 plugged into the top of the Shield.

flowchart LR; 
subgraph layout ["Train Layout"];
  direction LR;
  subgraph quad ["Quad-Node Card"];
	  direction LR;
 	  sm["SuperMini ESP32-S3 (4x)"] --> ss["SuperMini I/O <br/> Shield (4x)"];
  end
end
ss --> device["I/O Devices"];
classDef lSalmonStyle fill:#FFA07A,stroke:#333,stroke-width:2px,font-size:24px;
class bb lSalmonStyle;
classDef lightGrayStyle fill:#d3d3d3,stroke:#333,stroke-width:2px,font-size:24px;
class layout lightGrayStyle;
## Terminology

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.

High-Level Steps for Assembly:

Print PCB SuperMini I/O Status Shield PCB
Print
Component Identifier Count Type Value Package Purpose Orientation
Connectors            
J1, J2 2 9-Pin Female Headers Long Legged - Socket for Super-Mini ESP32-S3 development board(s). Required to allow insertion into the underlying headers. Position connection outward
Resistors            
R1-R8 8 Resistor 1kΩ 1206 SMD Current limiting protection for the LEDs. None
Indicators            
LED1-LED8 8 LED Green 1206 SMD Status indicator that an I/O line’s state is High when lit. Reference back of LED, position cathode towards PCB bottom edge
Transistors            
Q1 1 IC M54562FP SOP20 Darlington transistor array to amplify low-current signals from the (8) ESP32 GPIO pins, enabling driving of LEDs. Position indent (pin 1) towards PCB right edge

Tools Required

List of recommended tools.

Safety Precautions

Testing and Verification

PCB Configuration

  • No configuration required.

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. Component Orientation: the IC’s and LED’s are correctly oriented according to the PCB silkscreen or schematic.

Connectivity Testing

  1. Continuity Check: Use a multimeter in continuity mode to check for continuity between components.

Power-Up Tests

  1. Install the Shield into the female headers of the Quad-Node Card.
  2. Install a SuperMini ESP32-S3 module into the female headers of the Shield.
  3. Install the Quad-Node Card into an LCC Fusion Bus Hub.
  4. Install a Power-CAN Card in the same bus hub
  5. Apply Power to the Power-CAN Card.
  6. Check for Hot Components: Feel for components that are overheating, which could indicate a problem like a short circuit or incorrect component.

Functional Testing

  1. Using an LCC Configuration Tool
    1. Configure Event IDs for each of the Node’s input and output lines.
    2. For output, generate the configured LCC Event ID and verify that the corresponding LED is lite.
    3. For input, temporarily ground each of the I/O pins and verify that the corresponding LED is lite.

Troubleshooting

  • Correct orientation of both the IC and each of the LEDs is the most common issue.
  • Verify that the Quad-Node Card is receiving power and that the SuperMini ESP32-S3 module’s LED is lite. If not, check that the LCC Fusion Power-CAN Card is installed in the same Node Bus Hub and powered.

Appendences

Specifications

Specifications for the PCB include:

Characteristic  
Max Input / Output Lines Monitored 8
Max Input / Output Current (based on M54562FP IC) 500 mA

How It Works

The Quad-Node Card monitors the (8) I/O lines of the Quad-Node using a transistor to switch an LED on/off based on the state (High/Low) of the corresponding ESP32 GPIO pin. A current limiting resistor is utilized to protect the LED. The Shield uses the Vcc and GND provided by the Quad-Node Card connection to the LCC Fusion Node Bus Hub.

Design Notes

Implemented as an Arduino Shield (plugs in below ESP32 module);

  • Reduces number of wire traces
  • Allows for easy additional and removal
  • Uses transistor array to:
    • reduce components, allowing for fast on/off switching of LED switch based on the input / output line signal levels
    • allows higher current levels for the LEDs
  • Uses SMD resistors for consistency of SMD uses with other boards (another option would be a 9-pin Resistor Network, which didn’t save space or simplify the wiring).
  • LEDs are positioned on PCB’s outer edge for visibility

Protection

The SuperMini IO Status Shield’s protection is provided by the Quad-Node Card circuit protection.

References

  • Super-Mini LED to ESP32-S3 pin assignments. image-20240813095602688
SuperMini IO Status LED Super-Mini ESP32-S3 Pin
LED1 GP1
LED2 GP2
LED3 GP3
LED4 GP4
LED5 GP5
LED6 GP6
LED7 GP7
LED8 GP8
Last updated on: May 10, 2025 © 2025 Pat Fleming