FollowTV
Frequently shifting position in my laboratory viewing solution utilizing (3) ultrasonic sensors, (3) servos, an Arduino Uno and an excessive amount of averaging (see below) to lessen interference.




// FollowTV
// Vije Miller

#include "Servo.h"

const int atpin = 2;
const int aepin = 3;
const int btpin = 4;
const int bepin = 5;
const int ctpin = 6;
const int cepin = 7;

// For Cycle
const int num = 15;
int i = 0;
// Limit Distance
const int limit = 5500;
int hold = 500;

long adur, atot, afix;
long bdur, btot, bfix;
long cdur, ctot, cfix;

Servo lfs; // Left Front Speaker
const int lfsout = 69;
const int lfsin = 92;

Servo mon; // Monitor
const int monl = 145;
const int monc = 91;
const int monr = 45;

Servo rfs; // Right Front Speaker
const int rfsin = 63;
const int rfsout = 78;

void setup() {
Serial.begin(9600);

pinMode(atpin, OUTPUT);
pinMode(aepin, INPUT);
pinMode(btpin, OUTPUT);
pinMode(bepin, INPUT);
pinMode(ctpin, OUTPUT);
pinMode(cepin, INPUT);

lfs.attach(8);
mon.attach(9);
rfs.attach(10);

digitalWrite(atpin, LOW);
digitalWrite(btpin, LOW);
digitalWrite(ctpin, LOW);

lfs.write(lfsin);
mon.write(monc);
rfs.write(rfsin);

}

void loop() {

atot = 0;
for (i=0; i <= num; i++){
digitalWrite(atpin, HIGH);
delayMicroseconds(10);
digitalWrite(atpin, LOW);
adur = pulseIn(aepin, HIGH);
if (adur > limit) {
adur = limit;
}
atot = atot + adur;
}
afix = atot / num;

btot = 0;
for (i=0; i <= num; i++){
digitalWrite(btpin, HIGH);
delayMicroseconds(10);
digitalWrite(btpin, LOW);
bdur = pulseIn(bepin, HIGH);
if (bdur > limit) {
bdur = limit;
}
btot = btot + bdur;
}
bfix = btot / num;

ctot = 0;
for (i=0; i <= num; i++){
digitalWrite(ctpin, HIGH);
delayMicroseconds(10);
digitalWrite(ctpin, LOW);
cdur = pulseIn(cepin, HIGH);
if (cdur > limit) {
cdur = limit;
}
ctot = ctot + cdur;
}
cfix = ctot / num;

Serial.print(afix);
Serial.print(" ");
Serial.print(bfix);
Serial.print(" ");
Serial.println(cfix);

if (afix < bfix && afix < cfix) {
// Position 2
lfs.write(lfsout);
mon.write(monl);
rfs.write(rfsin);
}
else if (bfix < afix && bfix < cfix) {
// Position 1 and 3
lfs.write(lfsin);
mon.write(monc);
rfs.write(rfsin);
}
else if (cfix < afix && cfix < bfix) {
// Position 4
lfs.write(lfsin);
mon.write(monr);
rfs.write(rfsout);
}
else if (afix == limit && bfix == limit && cfix == limit) {
// Position Open
lfs.write(lfsout);
mon.write(monc);
rfs.write(rfsout);
}

delay(hold);
}

Archive
https://hackaday.io/project/7997-followtv

16:36:52 203-015