Math

Digital I/O
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Serial Comm.

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Overview
Storage
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BLE

This library performs all types of calculations including min/max, absolute value and the square root of a number. Users can also constrain a number within a range, re-map a number from one range to another, and calculate the value of a number raised to a power.

min

Description

Compares two values, returns the smaller one.

Syntax

min(x, y)

Parameters

x: The first number, any data type
y: The second number, any data type

Returns

The smaller of the two parameter values.

max

Description

Compares two values, returns the larger one.

Syntax

max(x, y)

Parameters

x: The first number, any data type
y: The second number, any data type

Returns

The larger of the two parameter values.

abs

Description

Computes and returns the absolute value of a number.

Syntax

abs(x)

Parameters

x: The number to be converted

Returns

If x is greater than or equal to 0, returns x; if less than 0, returns -x.

constrain

Description

Constrains a number to be within a range.

Syntax

constrain(x, a, b)

Parameters

x: The number to constrain, all data types
a: The lower end of the range, all data types
b: The upper end of the range, all data types

Returns

If x is between a and b, returns x; if x is less than a, returns a; if x is greater than b, returns b.

amap

Description

Re-maps a number from one range to another. For example, when the value is 5 within the range of 0 to 10, it is re-mapped to 50 in the range of 0 to 100.

Syntax

amap(value, fromLow, fromHigh, toLow, toHigh)

Parameters

value: The number to map
fromLow: The lower bound of the value's current range
fromHigh: The upper bound of the value's current range
toLow: The lower bound of the value's target range
toHigh: The upper bound of the value's target range

Returns

The value after mapping.

pow

Description

Calculates power (exponential).

Syntax

pow(base, exponent)

Parameters

base: Any value; (float)
exponent: The power to which the base is raised (float)

Returns

The result of the exponentiation (double).

sqrt

Description

Calculates the square root of a number.

Syntax

sqrt(x)

Parameters

x: The number, any value

Returns

The number's square root (double).

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Sample using constrain and pow.

#include <Arduino.h>
void setup(){
    Serial.begin(9600);
}
    
void loop(){
    Serial.println("Calculate the area of a circle ");
    Serial.println("Input value 0-9");
    while(!Serial.available());
        
    int d = Serial.read();
        
    d = constrain(d - 0x30, 0, 9); //convert from ASCII to numeric, and remove error value
    Serial.print(d);
    Serial.print(" x ");
    Serial.print(d);
    Serial.print(" x 3.14 = ");
    
    Serial.println(pow(d, 2) * PI);
}