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What is LED?#

LED is an electronic device which emits light when current passes through it. It is used as a visual Indicator in Industries.

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List of LED features implemented in Shunya stack#

With Shunya stack you can make LED

  1. Turn On/Off.

Using Led Shunya stack#

Requirements to use Led Shunya stack#

  1. Shunya OS installed (supported Arm devices) i.e (Raspberry Pi)
  2. 1x LED
  3. 1x 220 ohm resistor

Steps to use Led Shunya stack#

  1. Connect LED to your Arm device i.e (Raspberry Pi) .
  2. Turn On/Off LED.

Run the steps given below inside Shunya OS installed (supported Arm devices).

Step 1: Connect LED.#

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Step 2: Turn On/Off LED.#

Let's take an example use case: Say we need to

  • Read data from the temperature sensor connected to Shunya and,
  • Turn on LED when the temperature is high.

Steps are :

  1. Start with an ready to use template for sending messages via MQTT

    git clone
    cd examples/simple-examples/operate-actuators
  2. Open the operate-actuators.c in an text editor and modify as per your use case.

  3. For our example, we need to first get the temperature data, add the code in your main() function

    float temperature = 76.98; /* For now lets assume that the temperature is 76.89 Celsius*/
  4. Initialize LED, modify the code

    int ledPin = 36; /*Define LED pin, Note this should be as per your connection */
    pinMode(ledPin, OUTPUT); /* Initializes LED pin as Output */

    LED should be initialized only once in the whole program. Calling pinMode() multiple times will cause error with the library.

  5. To turn on LED, modify the code

    float temperature = 76.89; /* Assume that the temperature is 76.89 deg C*/
    if (temperature == 70.00f){
    digitalWrite(ledPin, ON); /* Turn on LED */
    } else {
    digitalWrite(ledPin, OFF); /* Turn off LED */
  6. Once you are done editing, save and compile the code , by running

    mkdir build && cd build
    cmake ../
  7. Run the code

    sudo ./operate-actuators

Facing errors with the component?#