If Statement (Conditional Statement)

The if() statement is the most basic of all programming control structures. It allows you to make something happen or not, depending on whether a given condition is true or not. It looks like this:

if (someCondition) {
   // do stuff if the condition is true
}

There is a common variation called if-else that looks like this:

if (someCondition) {
   // do stuff if the condition is true
} else {
   // do stuff if the condition is false
}

There's also the else-if, where you can check a second condition if the first is false:

if (someCondition) {
   // do stuff if the condition is true
} else if (anotherCondition) {
   // do stuff only if the first condition is false
   // and the second condition is true
}

You'll use if statements all the time. The example below turns on an LED on pin 13 (the built-in LED on many Arduino boards) if the value read on an analog input goes above a certain threshold.

Step 1: What You Need?

1 x Arduino Board ( Arduino UNO R3 used in this tutorial.)
1 x Potentiometer (10k Ohm) or Variable Resistor 
1 x Built-in LED
Female-to-Male Jumper Wires

Optional 
1 x LED (RED) & 220 Ohm Resistor 
Female-to-Female Jumper Wires

Arduino Uno R3 Acrylic Transparent Casing

Arduino Compatible UNO Ultimate Starter Kit / Learning Kit

Don't have components? Don't worry. Just click the component's name. 

Step 2: Build Your Circuit.

Step 3: Upload The Code.

1. Select the Arduino board type: Select Tools >> Board >> Select your correct Arduino board used.

2. Find the port number by accessing device manager on Windows. See the section Port (COM&LPT) and look for an open port named "Arduino Uno (COMxx)". If you are using a different board, you will find a name accordingly. What matters is the xx in COMxx part. In my case, it's COM3. So my port number is 3.

Select the right port: Tools >> Port >> Select the port number.

3. You can find this code in the example of Arduino IDE. 

Select File >> Examples >> 05. Control >> IfStatementConditional

Click press the "upload" button (see the button with right arrow mark).

In the code above, a variable called analogValue is used to store the data collected from a potentiometer connected to the board on analogPin 0. This data is then compared to a threshold value. If the analog value is found to be above the set threshold the built-in LED connected to digital pin 13 is turned on. If analogValue is found to be < (less than) threshold, the LED remains off.

Download: 

Arduino IDE

Sources:https://www.arduino.cc/en/Tutorial/ifStatementConditional

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My Robot Education Sdn. Bhd. (Robotedu.my) was founded in 2015 as the first robotics education centre in Malaysia to provide Arduino-based robotics courses for youths. Our vision is to be able to provide robotics education to every youth in Malaysia.