Floating points numbers, round, analogWrite

Projects Programming
1

I've had trouble diagnosing this issue in my code,

analogWrite(LED, round(getDist()) % 100);

returns
Compilation error: invalid operands of types 'float' and 'int' to binary 'operator%'
this is the full code

#include <math.h>
#define LED 15
#define trigPin 19
#define echoPin 18
#define MAX_DISTANCE 700
float timeOut = MAX_DISTANCE * 60;
int soundVelocity = 340;

void setup() {
  pinMode(LED, OUTPUT);
  pinMode(trigPin,OUTPUT);
 pinMode(echoPin,INPUT);
 Serial.begin(115200);

}

void loop() {
  
  delay(100);
  Serial.println("Distance: ");
  Serial.print(getDist());
  Serial.println("cm");
  analogWrite(LED, round(getDist()) % 100);
}

float getDist() {
 unsigned long pingTime;
 float distance;
 digitalWrite(trigPin, HIGH);
 delayMicroseconds(10);
 digitalWrite(trigPin, LOW);
 pingTime = pulseIn(echoPin, HIGH, timeOut);
 distance = (float)pingTime * soundVelocity / 2 / 10000;
 return distance;
}
2

Try


analogWrite(LED, ((int)round(getDist()))% 100);
3

operator% is remainder of integer division - try casting the double result of round to int

analogWrite(LED, (int)(round(getDist())) % 100);
1 Like
4

What is your intention with this bit? Do you really want to use "remainder of integer division"?

5

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