BeepIt (an Object Finder)





Introduction: BeepIt (an Object Finder)

Hi look at what we are going to do. A connected objet finder like a keyholder. We'll locate the object with a sound who's activated whith an android app i done. This app used Bluetooth.

Step 1: The Items Listing

We must do a few things and list item to use.

So we need: (links are present only to inform you. Buy where you want :))

Step 2: What We Are Going to Do

The app called BeepIt speak with a bluetooth module who was connected on an arduino.

The arduino is too big and the code in it will be added in a AtTiny45 Microcontroller.

- 1 - We prepare the Arduino to speak with the attiny45 :

Read this link that works for me.

After that :

Connect the Arduino Uno board to the USB port of your computer
Launch the Arduino program * Go (tools / serial port) select the COM port on which is connected to the Arduino board.

Go to (File / example) and click (ArduinoISP)

Go (Tools / Card Type) click (Arduino Uno)

Go to (File) click Upload

The Arduino is now able to program a ATtiny

Unplug the USB connector and make the small assembly.. (Picture Named : P1)

- 2 - Chose the Attiny45 in arduino IDE :

Reconnect the USB jack

Go (Tools / Card Type) click (Attiny and go another time to tools and chose processor 45 internal 8 MHz clock)

Go back into (Tools / programmer) click (Arduino as ISP) to indicate to the IDE that the UNO is used as a processor.

Go to (Tools) and click (Burn the boot sequence)

Go to (File) click Upload or icon * At the bottom of the window displays the following message Do not hold actually account if this message is that everything went well

- 3 - Program the Attiny45 in arduino IDE :

copy paste the code between ::::::::::::::::::::::::::


#include SoftwareSerial serieBT(0, 1); // on dit que l'on utilise les pins 10 et 11 à la place des pins 0 et 1 de la carte arduino

char val;

int buzzer = 2;// Borne de sortie buzzer connectée sur le attiny 85

void setup() {



pinMode(buzzer,OUTPUT); }

void loop() {

if (serieBT.available()) {

val =;

Serial.print(val); // on ecrit la valeur

switch (val) {

case '3' : digitalWrite(buzzer, HIGH);


digitalWrite(buzzer, LOW);


digitalWrite(buzzer, HIGH);


digitalWrite(buzzer, LOW);


digitalWrite(buzzer, HIGH);


digitalWrite(buzzer, LOW);


} } }


- 4 - Now the code is in the Attiny45

We have to test our assembly (watch picture named : P2 )

In our code the Bluetooth RX TX are connected on the Attiny45 pin 0 et 1 and the buzzer on the pin 2.

Step 3: The Application

Next we must test the application and you have to upload it on your phone.

Download the app

Here the new link :

and the

Ai file

if you want change things on it (the file works on this plateform

The application is free and you cant find it on Playstore for now so you have to download It.


But as you already know it the code to hear the speaker is 3. So if you got and bluetooth sender/app and that you send 3 to the bluetooth module it'll respond.

Step 4: What Else ?

Know you just have fix all this thing together. Watch the pictures to have an idea on my assembly.

I made a case with a laser cutter and test on with a 3d printer.

I hope this is done and that works for you.

If you use my app and create this "tracker" please let me know it. I'll be proud about it.
Thanks and vote for me ^^



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    19 Discussions

    Having a compile issue with the code. Using Arduino Version 1.8.3. Here's the error messages:

    fatal error: SoftwareSerial: No such file or directory

    #include <SoftwareSerial> serieBT(0, 1); //

    compilation terminated.

    exit status 1

    Error compiling for board Arduino/Genuino Uno.

    Any ideas where to start with this trouble shoot? So far I've reinstalled the SoftwareSerial zip to see if that helped, but it didn't.

    Also tried the code on Arduino 1.6 and that didn't work either.

    2 replies

    Hi. Dis you get the library SoftwareSerial? By the way i don't Knox why for now. must try to dis the job but don't have Arduino for now. Sorry

    i need help plz respond

    as iam confused to make the connections

    i need you help

    Whats the run time on this guy? More specifically, what's the power draw on the HC-05 module? I can't find any info on that after searching for awhile.

    I'm considering replicating this project however depending on how long the battery lasts, I might make one using a ESP8266 and a cool/crazy website GUI that depicts proximity. It all really hinges on which module is more energy efficient in deep sleep, etc...

    But there is nothing in that link
    It says that used has deleted the file

    Back in the 80s (or so) we had those fancy key finders. You needed to whistle and the whistled back. Now BT is whistling xD BTW: I remember they only whistled when you had them nearby and never when you were searching for them.

    4 replies

    More to the point, when they started going flat, they would just keep going off. So your there asleep and your keys start "crying" like a dead toy going flat....

    Oh the noise! It was like a dying balloon that seems to have an unlawfull amount of "flat air"

    Yea always happend like that. Like i said this project is for learning arduino and BT and to make project smaller. This kry findercis about 5cm/3cm. Its small but preferd smaller. I'll try to fo things with gps maybe.

    This is so cool! Thanks for sharing your object finder! Maybe I should make this, my wife is always loosing her keys!

    1 reply

    how long it will be able to receive Bluetooth signal, before battery running out...?

    1 reply

    Hi. I really don't know i just did it. We found gps tracker with buton batteries 3v. Mine was not new and i'm waiting for a new one i just bought. Will see. This project is for me a project to understand things and learn.