Question

Arduino PWM Example int Pin = 9; void setup() { pinMode (Pin, OUTPUT); } void loop() { analogWrite (Pin, 127); // Generate 50% duty cycle //on "Pin" }

Using the template provided in the lab details section, formulate a program for the Arduino to generate a PWM signal duty cycles between 0% and 100% at intervals of 10% where a button will increment the PWM signal. Remember the RC is 10 milliseconds. Provide a copy of the final code and explain how it works.

Answer 1

//code:--
#define Button 4
#define PWMsignal 11
int DutyCycle=0;
boolean pressed=LOW;
void setCycle(int);
void setup()
{
Serial.begin(9600);
pinMode(Button,INPUT);
pinMode(PWMsignal, OUTPUT);
}

void loop()
{
pressed=digitalRead(Button);
if(pressed==HIGH)
{
DutyCycle++;//this statement will increment the dutycycle
if(DutyCycle==11)
{
DutyCycle=0;
}
setCycle(DutyCycle);
Serial.print("the duty cycle is ");
Serial.print(DutyCycle);
Serial.print("0%\n");
delay(500);
}
}

void setCycle(int Cycle)//function for to generate pwm signal
{
switch(Cycle)
{
case 0:
analogWrite(PWMsignal,0);
break;
case 1:
analogWrite(PWMsignal,25);//here 10% of 255 =25.5 (let us approximate it to 25
break; // so here we have to increment the analog value by 25
case 2:
analogWrite(PWMsignal,50);//incrementing analog value by 25
break;
case 3:
analogWrite(PWMsignal,75);//incrementing analog value by 25
break;
case 4:
analogWrite(PWMsignal,100);//incrementing analog value by 25
break;
case 5:
analogWrite(PWMsignal,125);//incrementing analog value by 25
break;
case 6:
analogWrite(PWMsignal,150);//incrementing analog value by 25
break;
case 7:
analogWrite(PWMsignal,175);//incrementing analog value by 25
break;
case 8:
analogWrite(PWMsignal,200);//incrementing analog value by 25
break;
case 9:
analogWrite(PWMsignal,225);//incrementing analog value by 25
break;
case 10:
analogWrite(PWMsignal,255);
break;
default :
analogWrite(PWMsignal,0);
break;
}
  
}
  
  
  
  
  
  
  
  

Simulator time: 00:00:10.470 in Code Stop Simulation Export Share 1 Text + 1 (Arduino Uno R3) { Serial.begin(9600); pinMode(Button, INPUT); pinMode (PWMsignal, OUTPUT); } + abcde pg void loop() { pressed=digitalRead(Button); if(pressed==HIGH) { DutyCycle++; // this statement will increment the dutycycle if(DutyCycle==11) AREF GND 13 12 -11 { DutyCycle=0; IORE RESET L 3.3V 5V GND GND Vn0 18 ...14 } O UNO 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 AO L AID A2 A3 LA LAS setCycle(DutyCycle); Serial.print("the duty cycle is "); Serial.print(DutyCycle); Serial.print("O\n"); delay(500); } TX-1 RX40 } void setCycle(int Cycle) // function for to generate pwm signal { switch(Cycle) a b c de Fghii { case 0: analogWrite(PWMsignal, 0); break; - - - - 1 - Serial Monitor the duty cycle is 10% the duty cycle is 20% the duty cycle is 30% the duty cycle is 40% the duty cycle is 50% the duty cycle is 60% Send Clear M

working of the circuit:--
here the circuit will continuously monitor whether the button is pressed or not if the button is pressed then the duty cycle will be incremented by "1", then the setCycle() function is used to determine which value to be written in the analogWrite function to produce PWM signal at 11th pin.
if the duty cycle is reached 10 then it is again set to "0" by using a simple "if statement".
in setCycle() function a switch statement is used to produce different duty cycle of the PWM signal, if the duty cycle is 10% then an analog value 25 will be written at the 11th pin, if the duty cycle is 20% then the analog value 50 will be written at the 11th pin, so here different
analog value will be written at the 11th pin depending upon the duty cycle.
here we need to increment the duty cycle of the PWM signal by 10% when each time the button is pressed, the Arduino PWM signal value range is 0 to 255, so 10 percent of 255 is the value we have to increment in the analog write function as shown in the code.
so 10 percent of 255 will be
10*255/100=25.5
= let us take 25 as approximated value
so when the button is pressed then the analog value is incremented by a factor of 25 in the switch statement.