For celebrating Arduino Day 20201 , here is an amazing mashup project: a Talking Useless Box called the Switch of Enlightenment.


Like all useless boxes, throwing the switch will cause a servo controlled arm to turn the switch back off after a random time delay.

In my build version, an ISD1760PY voice recorder is also triggered to utter some useless, but funny, comments  or sound effects.


The ISD1760PY is unique as the voice recordings can be changed on the fly.

The ISD1760PY demo board has switches and a Electret microphone build in.

I did have to cobble the ISD1760PY so it could be hardwired to the Arduino Nano.


This version has a strobing bar LED to bring attention to the switch.


Here is the video showing it in action. The video also shows how the useless box was built and tested.



Here is the schematic


The code:







#include <Servo.h>



Servo myservo;  // create servo object to control a servo

// twelve servo objects can be created on most boards



int pos = 7;    // variable increment LED Bar segment

int SwitchIsOn = LOW; //initiale var to LOW

int SwitchIsOnLastScan = LOW; //initiale var last scan's value to LOW

int RDY = HIGH ; //initiaze READY signal from ISD170 PY

long randNumber; // random number for servo to wait to flip switch



void setup() {

  myservo.attach(4);  // attaches the servo on pin 9 to the servo object


  pinMode(2, OUTPUT);   // falling edge triggered output to ISD1760PY voice card FWD input, selects next track. Pull LOW to trigger

  pinMode(3, OUTPUT);  //  falling edge triggered output to ISD1760PY voice card PLAY input. Pull LOW to trigger

  pinMode(5, INPUT);   // ISD1760PY Ready signal. Pulled LOW when ISD is playing or busy. HIGH when available


  pinMode(6, INPUT);   // panel mounted toggle switch input. TRUE means Closed and starts the circus



  pinMode(7, OUTPUT);  //LED BAR segment 1

  pinMode(8, OUTPUT);  //LED BAR segment 2

  pinMode(9, OUTPUT);  //LED BAR segment 3

  pinMode(10, OUTPUT);  //LED BAR segment 4

  pinMode(11, OUTPUT);  //LED BAR segment 5

  pinMode(12, OUTPUT);  //LED BAR segment 6

  pinMode(13, OUTPUT);  //LED BAR segment 7



  randomSeed(analogRead(1));//generate a random #




void loop() {

   digitalWrite(3, HIGH); //start off with no chatting

   digitalWrite(2, HIGH);



  for (pos = 7; pos <= 14; pos += 1)


    digitalWrite(pos, HIGH);   // sets the "scanner" LED bar segment on


    SwitchIsOn = digitalRead(6);   // read the input pin value to start operation


    RDY = digitalRead(5);   // read the input pin 5 value ,connected to RDY signal of ISD1760PY. TRUE is ready to play


    if ((SwitchIsOn == HIGH) && (RDY==HIGH)) ///may need to one shot the switch input


          // blank the LEDs while the cycle executes

              digitalWrite(7, LOW);   //

              digitalWrite(8, LOW);   //

              digitalWrite(9, LOW);   //

              digitalWrite(10, LOW);   //

              digitalWrite(11, LOW);   //

              digitalWrite(12, LOW);   //

              digitalWrite(13, LOW);   //





          // PLAY TRACK


           digitalWrite(3, LOW);   // trigger sound card message , pull PLAY input to ground

          delay (50); //set trigger width, debounce time = 192/Fs, figure worst case = .048msec

           digitalWrite(3, HIGH);   // trigger sound card message falling edge


           randNumber = random(1500,5000);

           delay(randNumber); // add some small randomness for turning off the main switch, give the soundtrack some time to start playing


           HitSwitch(); // turn the switch off


             // wait for track to finish

           RDY = digitalRead(5);   // read the input pin value of the ISD1760PY Ready signal TRUE is Ready

           while (RDY == LOW)  // keep checking to see of track is done playing

                {delay (5);

                RDY = digitalRead(5);




             // increment to next track when ready


                FWDtoNextMessage();   // pulse output to FWD



         delay (30);  //on time of LED bar segment

         digitalWrite(pos, LOW);   // turns off LED segment







void HitSwitch ()



    delay(5);   // spaceholder for inserting randomness to speed and response time

    myservo.write(90);              // tell servo to go to trip switch  position

    delay(300);                       // waits 15ms for the servo to reach the position

    myservo.write(0);                  // tell servo to go back to home position




void FWDtoNextMessage()


            digitalWrite(2, LOW);   // increment to next sound card message, pull FWD input to ground

            delay (40); //set trigger width, debounce time = 192/Fs, figure worst case = .048msec

            digitalWrite(2, HIGH);   // sound card message falling edge

            delay(100); // LED flash time head start for 1760PY to load in new signal