How to Use Grove-LED Button: Examples, Pinouts, and Specs

The Grove-LED Button is a versatile module that combines an LED and a push button into a single, compact unit. This module allows users to control the LED's state (on/off) with the press of a button, making it ideal for interactive projects. It is part of the Grove ecosystem, which simplifies prototyping and development by using standardized connectors and plug-and-play functionality.

• Interactive projects and prototypes
• User input interfaces
• Visual feedback systems
• Educational projects for learning electronics
• DIY projects requiring simple button and LED integration

The Grove-LED Button is designed for ease of use and compatibility with microcontrollers like Arduino, Raspberry Pi, and others. Below are its key technical details:

The Grove-LED Button uses a 4-pin Grove connector. The pinout is as follows:

The Grove-LED Button is straightforward to use in a circuit. Follow the steps below to integrate it into your project:

1. Hardware Setup:

   • Connect the Grove-LED Button to a Grove Base Shield or directly to your microcontroller using a Grove cable.
   • Ensure the module is connected to a digital I/O port (e.g., D2 or D3 on an Arduino UNO).

2. Circuit Diagram:

   • The SIG_LED pin is connected to a digital output pin on the microcontroller to control the LED.
   • The SIG_BTN pin is connected to a digital input pin to read the button's state.

Below is an example Arduino sketch to demonstrate how to use the Grove-LED Button. The code toggles the LED state each time the button is pressed.

// Define the pin numbers for the LED and button
const int ledPin = 2;  // Connect SIG_LED to digital pin 2
const int buttonPin = 3;  // Connect SIG_BTN to digital pin 3

// Variable to store the button state
int buttonState = 0;  
// Variable to track the LED state
bool ledState = false;  

void setup() {
  // Initialize the LED pin as an output
  pinMode(ledPin, OUTPUT);
  // Initialize the button pin as an input
  pinMode(buttonPin, INPUT);
  // Start the serial monitor for debugging
  Serial.begin(9600);
}

void loop() {
  // Read the current state of the button
  buttonState = digitalRead(buttonPin);

  // Check if the button is pressed
  if (buttonState == HIGH) {
    // Toggle the LED state
    ledState = !ledState;
    // Update the LED output
    digitalWrite(ledPin, ledState ? HIGH : LOW);
    // Print the LED state to the serial monitor
    Serial.print("LED is now: ");
    Serial.println(ledState ? "ON" : "OFF");

    // Debounce delay to avoid multiple toggles
    delay(200);
  }
}

• Debouncing: The button may produce multiple signals due to mechanical bouncing. Use a small delay (e.g., 200ms) to debounce the button.
• Voltage Compatibility: Ensure the module is powered with the correct voltage (3.3V or 5V) to avoid damage.
• Signal Pins: Avoid connecting the SIG_LED or SIG_BTN pins directly to VCC or GND without proper current-limiting resistors or microcontroller control.

1. The LED does not light up:

   • Verify that the SIG_LED pin is connected to a digital output pin on the microcontroller.
   • Check the power supply voltage (3.3V or 5V) and ensure proper connections.

2. The button press is not detected:

   • Ensure the SIG_BTN pin is connected to a digital input pin on the microcontroller.
   • Check for loose or incorrect connections in the Grove cable.

3. The LED flickers or behaves erratically:

   • This may be caused by button debounce issues. Add a small delay (e.g., 200ms) in the code after detecting a button press.

4. The module does not work at all:

   • Confirm that the Grove Base Shield or Grove cable is properly connected.
   • Test the module with a different digital I/O port on the microcontroller.

Q: Can I use the Grove-LED Button with a Raspberry Pi?
A: Yes, the module can be used with a Raspberry Pi. Use the GPIO pins to control the LED and read the button state. You may need a Grove Pi+ or Grove HAT for easier integration.

Q: Can I change the LED color?
A: The module comes with a fixed red LED. To use a different color, you would need to modify the hardware by replacing the LED.

Q: Is the button latching or momentary?
A: The button is momentary, meaning it only stays pressed while you hold it down.

Q: Can I use this module with 3.3V systems?
A: Yes, the Grove-LED Button is compatible with both 3.3V and 5V systems.

By following this documentation, you can easily integrate the Grove-LED Button into your projects and troubleshoot any issues that arise. Happy prototyping!