Example 19 ‐ Buzzer tone in relation to distance - GSTCH/SketchMadeEASY GitHub Wiki
Buzzer tone frequence in relation to distance measured by an Ultrasonic Sensor. If Sketch Made EASY is installed, it can be opened via menu: "File:/Example/SketchMadeEASY/Examples/18-StepperAngleControlledByJoystick".

#include <Easy.h>
//****************************************************************
#define ECHO_PIN 30
#define TRIGGER_PIN 31
#define MEASURE_INTERVAL_MSEC 1000
#define BUZZER_FREQUENCY_MIN 20
#define BUZZER_FREQUENCY_MAX 1000
#define BUZZER_PIN 4
void setup()
{
//((*** Initialize: Configure your sketch here....
//** Define Input
Input* distanceSensor = new UltrasonicRangefinder(ECHO_PIN, TRIGGER_PIN, MEASURE_INTERVAL_MSEC);
//** Define Actuators:
Actuator* buzzer = new Buzzer(BUZZER_PIN, BUZZER_FREQUENCY_MIN, BUZZER_FREQUENCY_MAX);
//** Define logic with condition and relation
Relation* relationBuzzerOn = new Relation1to1(NULL, buzzer, distanceSensor);
// ***))
// Initialize control
ControlManagerFactory::GetControlManager()->Setup();
}
//*****************************************************************
void loop() {
//*** Run: No additional code is required
ControlManagerFactory::GetControlManager()->Loop();
// Depending on Arduino it needs a short delay. Do not add any other delays!
delay(1);
}