Question

ARDUINO

Create a function that will ask the user to enter the values for each of the three colors (red, green and blue) between 0 and 255. The function should check that the user does not enter a number bigger than 255 or smaller than 0. If this happens, the function should keep asking for a valid number.

Answer 1

Please up vote .comment if any query . Thanks for question . Be safe .

Note : check attached image for output .code compiled and tested in Arduino IDE.

Program :

void setup() {
// put your setup code here, to run once:
Serial.begin(9600); //uart starts at baudrate 9600
delay(100); //delay to settle uart

getColorCode(); //function to get color code

}

void loop() {

}

void getColorCode()
{

int red=-1,green=-1,blue=-1; //assign -1 to color code integer

while(red>255 || red<0) //if red <0 or >255 keep asking for color
{
    red=serialData("red"); //function takes code for red color and return integer value of code
}

while(green>255 || green<0) //keep asking till valid green color code
{
    green=serialData("green"); //pass color name to get value
}

while(blue>255 || blue<0) //blue color code
{
    blue=serialData("blue");
}

Serial.print("Red color code is : "); //print user input color code
Serial.println(red); //red color code

Serial.print("Green color code is : ");
Serial.println(green); //green color

Serial.print("Blue color code is : ");
Serial.println(blue); //blue color code

}

int serialData(String colorName) //argument a string color name
{
String color="";
Serial.println("Enter color code of "+colorName+" : "); //prompt for color code passed by user
//when data not available serial.available return -1 else number of data available on serial
while(!Serial.available()); //wait till did not input data on serial

while(Serial.available()) //read serial data
{
    color+=(char)Serial.read(); //read data from serial as char and add to color
}
Serial.println("Your entered code is : "+color); //print user input
return color.toInt(); //convert string to integer and return
}

Output :

Please comment if any changes , and up vote .