Arduino Programming Language Articles - Page 3 of 10

Logical NOT is performed using the ! operator. The truth table is given below −ExpressionOutputTFFTAs you can see, the logical NOT inverts the truth value of the expression.ExampleThe usage can be understood from the example given below −void setup() {    // put your setup code here, to run once:    Serial.begin(9600);    Serial.println();    int i = 10;    if (!(i > 10)) {       Serial.println("i is NOT greater than 10");    }    else {       Serial.println("i is greater than 10");    } } void loop() {    // put your ... Read More

Unlike logical NOT, which inverts the truth value of an expression, the bitwise NOT applies to each bit of a number and inverts its value (0 to 1 and 1 to 0). The operator is ~.The syntax thus is ~a, where a is the number on which this operator has to apply.Please note, that all the leading 0s in the number’s representation are also converted to 1. For example, if your board uses 16 bits to represent an integer, then here’s what ~10 will look like0000000000001010101111111111110101~10=-11As you can see, each bit of 10 got inverted. This number corresponds to, using ... Read More

The logical AND is denoted by the && operator, while the logical OR is denoted by the || operator.SyntaxExpression1 && Expression2ORExpression1 || Expression2Where expression1 and expression2 evaluate to Boolean values (true or false). The output of these statements is determined by the truth tables of logical AND and OR.The truth table for AND is given below −Expression1Expression2OutputTTTFTFTFFFFFAs you can see, both the expressions have to be true for the AND statement to output true.The truth table for OR is given below −Expression1Expression2OutputTTTFTTTFTFFFAs you can see, even if one of the expressions is true, the OR statement will output true.ExampleThe following ... Read More

Bitwise AND/ OR means AND/ OR performed at a bit-level, individually. Each number has its binary representation. When you perform the bitwise AND of one number with another, the AND operation is performed on the corresponding bits of the two numbers. Thus, LSB of number 1 is ANDed with the LSB of number 2, and so on.The bitwise AND operation in Arduino is & and the bitwise OR operator is |.Syntaxa & bfor AND.a | bfor OR.The truth table for AND isPQp & q000010100111The truth table for OR is −PQp & q000011101111Since these are bitwise operators, we need to perform ... Read More

The pow() function of Arduino can be used for evaluating exponential expressions. Any expression of the form ab can be expressed as pow(a, b). For example 23 becomes pow(2, 3).The type for both the base (a) and the exponent (b) is float. This function returns a double.Examplevoid setup() {    // put your setup code here, to run once:    Serial.begin(9600);    Serial.println();    float base = 2;    float exponent = 3;    Serial.println(pow(base, exponent)); } void loop() {    // put your main code here, to run repeatedly: }OutputThe Serial Monitor Output is shown below −You are ... Read More

In order to get the max/ min values of an array in Arduino, we can run a simple for loop. Two implementations are shown below. One uses the max() and min() functions of Arduino, and the other uses the > and < operators.The max and min functions have the following syntax: max(a, b) and min(a, b), and they return the max and min values out of a and b respectively.Implementation 1 − Using > and < operatorsvoid setup() {    // put your setup code here, to run once:    Serial.begin(9600);    Serial.println();    int myArray[6] = {1, 5, -6, ... Read More

Arduino has support for several popular math functions, square and square root being among them. Let’s look at the square root first.Syntaxsqrt(x)where x is a number of any data type. It returns a double.For square, you ideally shouldn’t need a separate function. You can just multiply the number by itself.x_squared = x*x;However, Arduino does have a separate function for calculating squares. The syntax is −sq(x) where x is a number of any data type. This again returns a double.ExampleThe following example illustrates the use of these functions −void setup() {    // put your setup code here, to run once:   ... Read More

In a previous article, we used the TimerOne library to add timer interrupts to Arduino. But what if we wish to generate timer interrupts without a third-party library? In that case, you will directly have to meddle with the timer registers in Arduino. In this article, we will just introduce the registers relevant to timer operations and explain their significance. We will also provide the page numbers of the ATmega328 (used in Arduino Uno) datasheet wherein you can find detailed information on these registers.You can find the datasheet here −https://ww1.microchip.com/downloads/en/DeviceDoc/Atmel7810-Automotive-Microcontrollers-ATmega328P_Datasheet.pdfTCCRxA and TCCRxBThese are timer control registers. The x stands for ... Read More

The do-while loop’s syntax in Arduino is similar to the syntax in C. It is given below −do{    //Code } while (condition);Note the semicolon at the end.Examplevoid setup() {    // put your setup code here, to run once:    Serial.begin(9600);    Serial.println();    int i = 5;    do{       Serial.println(i);       i--;    } while(i > 0); } void loop() {    // put your main code here, to run repeatedly: }OutputThe Serial Monitor output is shown below −

In an earlier article, we have seen how PWM can be set on Arduino Uno using the analogWrite() function. Pins 3, 5, 6, 9, 10 and 11 of Arduino Uno can support PWM. The frequency of the square wave is 490 Hz (about 2 ms time period) on all pins except 5 and 6, on which it is 980 Hz (about 1s time period). With analogWrite() you get control over the duty cycle, but not on the frequency of the generated square wave.In this article, we will look at another way of setting PWM in Arduino Uno, specific to Timer1. The advantage ... Read More