Example 2 - Button

This example goes over how to use the built-in button with the internal pull-up resistors on the microcontroller. While we are at it, we will also use the built-in LED to visually see what is going on right on the board without the need to open the Arduino Serial Monitor.

Hardware Hookup

Connect the USB cable to the SparkFun Thing Plus NORA-W306 and the other end to your computer's COM port.

USB Cable inserted into Thing Plus NORA-W306

Arduino Code

Let's upload the sketch to check if there is a button press. The following code is a modified example that was built into the Arduino IDE (File > Examples > 02.Digital > Button ) since there are no pull-up resistors connected to the button and the LED is on a different I/O pin.

You can also copy and paste the following code in the Arduino IDE. Select the correct board definition from the menu (in this case, Tools > Board > Realtek Ameba Boards (32-bits ARM Cortex-M33 @200MHz) > SparkFun Thing Plus NORA-W306 (RTL8720DF)). Then select the correct COM port that the board enumerated to (in this case, it was COM13). Hit upload button.

/*
  Button

  Turns on and off a light emitting diode (LED) connected to digital pin 18,
  when pressing a pushbutton attached to pin 2.

  The circuit:
  - Built-in LED attached from pin 18 to ground and current limiting resistor
  - Built-in pushbutton attached to pin 2 from +5V



  modified 2024
  by Ho Yun "Bobby" Chan

  created 2005
  by DojoDave <http://www.0j0.org>
  modified 30 Aug 2011
  by Tom Igoe

  This example code is in the public domain.

  https://www.arduino.cc/en/Tutorial/BuiltInExamples/Button
*/

// constants won't change. They're used here to set pin numbers:
const int buttonPin = 2;  // the number of the pushbutton pin
const int ledPin = 18;    // the number of the LED pin

// variables will change:
int buttonState = 0;  // variable for reading the pushbutton status

void setup() {
  // initialize the LED pin as an output:
  pinMode(ledPin, OUTPUT);
  // initialize the pushbutton pin as an input pullup:
  pinMode(buttonPin, INPUT_PULLUP);
}

void loop() {
  // read the state of the pushbutton value:
  buttonState = digitalRead(buttonPin);

  // check if the pushbutton is pressed. If it is, the buttonState is HIGH:
  if (buttonState == HIGH) {
    // turn LED on:
    digitalWrite(ledPin, HIGH);
  } else {
    // turn LED off:
    digitalWrite(ledPin, LOW);
  }
}

Once uploaded, check the LED labeled as 18 on the board. Pressing down on the user button connected to pin 2 will light up the LED. Releasing the button, the LED will turn off.

SparkFun Thing Plus NORA-W306 Button Press with LED Turned On