Introduction: SPhocsLock - Simple Phone Controlled Strike Lock - Cheapest Solution

You are looking for a cheap and easy solution to open the door(or whatever) with your phone ?

Here it is:

Sometimes people forget to take the latchkey but they never forget their cellphone so as i.
What could be better than open the door with the cellphone.
Of course i wanted a simple and affordable solution that works with almost any phone and there is no app needed.
The phone must only support audio via bluetooth. The two main parts are an audio bluetooth dongle und a small arduino microcontroller.

Step 1: How It Works

I'm using the audio via Bluetooth function that most of the modern cellphones/smartphones are supporting.
You have to pair the phone one time with the Bluetooth dongle and than everytime you come close the door/dongle the two devices will automatically connect. What happens than ?
A small audio file that was copied to the phone will be played. On Android devices you can place a link Icon on the start screen you just press the icon and the audio file will be played.
The file contains a short and fast morse code. The arduino receive this from the Bluetooth dongle and check if the code is ok, after that a relay will close the circuit from the lock for a short time and voila ! The door is open .

Step 2: What You Need

- Bluetooth audio dongle

- Arduino pro mini 5V

- USB Adapter for programming the arduino

- relay 5VDC/2A

- mosfet BS 108

- voltage regulator 7805

- 5x diode 1N4001

- resistors: 2x 100k, 1k, 10k

- caps: 2x 10nF, 4,7nF, 2x 220µF, 10µF

- power supply/transformer output 8-12V AC

- i use a stripboard

- and of course a strike/electrical lock and a phone !

Step 3: Schematic

i also attached a pdf

Step 4: Arduino Code

Install the latest Arduino IDE and connect the usb-progger with your pc/arduino.

Now you can upload the attached files.

If you have no experience in programming Arduino, look at this guide.

In the SPhocsLock.ino you find these lines where to change the password and pin configuration:

#include "MorseEnDecoder.h"
const byte morseInPin = 2;  
const byte DoorPin = 13; 
const char password[ ] = "TEST";  // <----------------- Password 
const long OpenTime = 1000 ;// in ms 
const byte wpm = 50; 
// Instantiate Morse objects
morseDecoder morseInput(morseInPin, MORSE_AUDIO, MORSE_ACTIVE_HIGH);

Step 5: The "morse Code Audio File"

You can either install a programm like this or use this website to create the audio file.

Choose custom settings with 50 wpm and 1khz.

A shorter password generates a shorter audio file !!!

Copy the file on your phone in a seperate folder so the audio player will only play this one.

On Android you can create a shortcut icon (with a file explorer) at the start screen.

And don't forget to change the password :-)

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