M5Stack Mechanical Key Button Unit

The Mechanical Key Button Unit from M5Stack is a single mechanical key input unit with a built-in RGB LED.

The key shaft adopts a Blue switch with a tactile bump and audible click feature. The unit has an embedded programable SK6812 RGB LED and supports 256 level brightness. Two digital IOs are available for key status and LED control key status and lighting control. Suitable for multiple HMI applications.

Features

• Blue switch with tactile bump and audible click
• Programable RGB LED - SK6812

Package Contents

• 1x Unit Key
• 1x HY2.0 4-pin Cable (20cm)

Specifications

Power Supply	DC 5V
Output Logical Signal	DC 3.3V
Standby Current	DC5V@2mA
Operating current	DC5V@13mA
Net weight	7.6g
Gross weight	13.1g
Product Dimensions	40 * 24 * 22.6mm
Package Size	90 * 135mm

Resources

• Product Documentation
• Schematic
• Arduino Example:
  • UNIT Key Example
  • FastLED Library
  • FastLED API Reference

Pinout

M5CORE - PORT B	G36	G26
UNIT Key	Button Input	RGB LED Control

Arduino Example Code

#include 
#include 

uint8_t ledColor = 0;

#define KEY_PIN  36
#define LED_PIN 26

CRGB LED[1];

void setup() {
    M5.begin();
    M5.Lcd.setTextSize(3);
    M5.Lcd.print("\n UNIT-KEY Example\n\n    Key State:");
    /* Init key pin */
    pinMode(KEY_PIN, INPUT_PULLUP);
    /* Init RGB led */
    FastLED.addLeds(LED, 1);
    LED[0] = CRGB::Blue;
    FastLED.setBrightness(0);
}

void loop() {
    /* If Key was pressed */
    if (!digitalRead(KEY_PIN)) {
        M5.Lcd.setCursor(75, 130);
        M5.Lcd.print((" Pressed "));
        FastLED.setBrightness(255);
        FastLED.show();
        /* Hold until the key released */
        while (!digitalRead(KEY_PIN))
            ;
    } else {
        M5.Lcd.setCursor(75, 130);
        M5.Lcd.println(("Released"));
        FastLED.setBrightness(0);
        FastLED.show();
    }
    delay(100);
}