---
title: "StatusLight - LED Status Indicator Component"
description: "A component for controlling a status LED with simple on/off and blinking capabilities"
keywords: ["ESP32", "status LED", "indicator", "modbus", "feedback"]
---

## StatusLight

**Path**: [`src/StatusLight.h`](../../src/StatusLight.h)

**Revision History**: Initial documentation

StatusLight is a component for controlling a status LED, providing simple on/off and blinking capabilities. It supports Modbus integration for remote monitoring and control of the status indicator.

## REQUIREMENTS

- **Hardware**:
  - Digital GPIO pin for controlling an LED
- **Software**:
  - Configuration for pin assignment in `config.h`
  - Modbus address configuration in `config-modbus.h`

## FEATURES

- Steady on/off LED control
- Blinking functionality with configurable interval
- Modbus integration for remote monitoring and control
- Support for multiple instances with different Modbus addresses
- Component state tracking

## DEPENDENCIES

- [Arduino.h](https://github.com/espressif/arduino-esp32)
- [ArduinoLog.h](https://github.com/thijse/Arduino-Log)
- [Component.h](../../src/Component.h)
- [macros.h](../../src/macros.h)
- [xmath.h](../../src/xmath.h)
- [Bridge.h](../../src/Bridge.h)
- [enums.h](../../src/enums.h)
- [config.h](../../src/config.h)
- [config-modbus.h](../../src/config-modbus.h)
- [modbus/ModbusTCP.h](../../src/modbus/ModbusTCP.h)

```mermaid
graph TD
    StatusLight --> Component
    StatusLight --> Bridge
    StatusLight --> Arduino
    StatusLight --> ArduinoLog
    StatusLight --> macros
    StatusLight --> xmath
    StatusLight --> enums
    StatusLight --> config
    StatusLight --> configmodbus
    StatusLight --> ModbusTCP
```

## BEHAVIOUR

```mermaid
stateDiagram-v2
    [*] --> OFF
    OFF --> ON: set(1)
    ON --> OFF: set(0)
    OFF --> BLINK: set(0,1)
    ON --> BLINK: set(1,1)
    BLINK --> OFF: set(0,0)
    BLINK --> ON: set(1,0)
```

## TODOS

### PERFORMANCE

- Consider using hardware PWM for smoother blinking effects
- Review blinking implementation for efficiency (currently using polling in loop)

### SECURITY

- Add validation for input parameters in set() method
- Consider authentication for Modbus write operations

### COMPLIANCE

- Ensure blinking rates are appropriate for industrial environments
- Comply with industrial standards for visual indicators

### RECOMMENDATIONS

- Use hardware with appropriate LED drivers for high-brightness applications
- Consider adding additional blink patterns for varied status indications
- Add support for RGB LEDs for multi-state visualization

## EXAMPLE

Below is an example of how to initialize and use the StatusLight component:

```cpp
#ifdef PIN_STATUS_LIGHT
  statusLight = new StatusLight(
      this,               // owner
      PIN_STATUS_LIGHT,   // pin
      COMPONENT_KEY_FEEDBACK_0,  // id
      MB_MONITORING_STATUS_FEEDBACK_0  // modbusAddress
  );
  if (statusLight)
  {
    components.push_back(statusLight);
    Log.infoln(F("StatusLight initialized. Pin:%d, ID:%d, MB:%d"),
               PIN_STATUS_LIGHT, COMPONENT_KEY_FEEDBACK_0, 
               MB_MONITORING_STATUS_FEEDBACK_0);
              
    // Example usage
    statusLight->on();  // Turn the LED on
    // statusLight->off(); // Turn the LED off
    // statusLight->setBlink(true); // Make the LED blink
  }
  else
  {
    Log.errorln(F("StatusLight initialization failed."));
  }
#endif
```

### References