Question

Add to this arduino sketch such that you can add three externally-connected LEDs to your circuit board. Modify this code such that the first LED turns on if the ADC output value is between 0 and 340, the second LED turns on if the ADC output value is between 341 and 680, and the third LED turns on if the ADC output value is above 680

int potpin=0;// initialize analog pin 0
int ledpin=13;// initialize digital pin 13
int val=0;// define val, assign initial value 0
void setup()
{
pinMode(ledpin,OUTPUT);// set digital pin as “output”
Serial.begin(9600);// set baud rate at 9600

}
void loop()
{
digitalWrite(ledpin,HIGH);// turn on the LED on pin 13
delay(50);// wait for 0.05 second
digitalWrite(ledpin,LOW);// turn off the LED on pin 13
delay(50);// wait for 0.05 second
val=analogRead(potpin);// read the analog value of analog pin 0, and assign it to val 
Serial.println(val);// display val’s value
}

Answer 1

Here our task is to create an arduino sketch to turn on and off 3 LEDs according to the ADC input values

Things to consider before coding

• We have to define 3 variable to store arduino pin number in which 3 leds are going to be connected(led1,led2,led3) and set them as output pins
• Create another varaible which store the pin at which pot is connected and set them as input pin
• In loop() function ,analog read the pot  pin and store it in variable val
• create 3 if statement which check 3 conditions mentioned in questions (here we have to use Logical AND operator( &&) .This operator return TRUE only if  two conditions mentioned are true)  
• In the body of each if statements turn on and off apropriate LEDs
• introduce some delay in each if body

CODE

CURCUIT DIAGRAM

text version of the code given below

int potpin=A0;// initialize analog pin 0
int led1=13;// initialize digital pin 13
int led2=12;// initialize digital pin 13
int led3=11;// initialize digital pin 13

int val=0;// define val, assign initial value 0
void setup()
{
pinMode(led1,OUTPUT);// set led1 pin as “output”
pinMode(led2,OUTPUT);// set led2 pin as “output”
pinMode(led3,OUTPUT);// set led3 pin as “output”
Serial.begin(9600);// set baud rate at 9600

}
void loop()
{
val=analogRead(potpin);// read the analog value of analog pin 0, and assign it to val
if ( val>0 && val <340){ // checking conditions
digitalWrite(led1,HIGH);// turn on the LED1 on pin 13
digitalWrite(led2,LOW);// turn off the LED2 on pin 12
digitalWrite(led3,LOW);// turn off the LED3 on pin 11
delay(50); //wait for 0.05 seconds
}
if ( val >340 && val<680 ) { // checking conditions
digitalWrite(led1,HIGH);// turn on the LED1 on pin 13
digitalWrite(led2,HIGH);// turn on the LED2 on pin 12
digitalWrite(led2,LOW);// turn off the LED3 on pin 11
delay(50); //wait for 0.05 seconds
}
if (val >=680 ){ // checking conditions

digitalWrite(led1,HIGH);// turn on the LED1 on pin 13
digitalWrite(led2,HIGH);// turn on the LED2 on pin 12
digitalWrite(led2,HIGH);// turn on the LED3 on pin 11
delay(50); //wait for 0.05 seconds
}
}