DIY smart doorbell based on Raspberry Pi 5

Created for "Workshop: Build your Own Smart Doorbell" workshop ZIP media Lab Rotterdam by Roos Groothuizen & Dave Borghuis

Find the tutorial with pictures here: https://www.instructables.com/Smart-Doorbell-Using-Raspberry-Pi-5-Jitsi-Telegram/

• Raspberry Pi 5 (tested with 4 & 5)
• Power adapter (Pi is icky about this so buy the right one.)
• microSD card for OS, minimal 16GB type A1 or better
• Pi Camera (with Pi5 cable)
• USB External speaker (that acts like a soundcard, so no 3,5mm plug!)
• USB Microphone
• a button
• LED
• 150 Ohm resistor (for led)
• wires to led and button

Make image for your pi with Pi Imager, select the correct hardware and "Raspberry Pi OS (64-bit)" as image to create. Select your SD card and wait until the imager is done.

Put the SD card in your Pi and turn it on. After a quick automatic reboot the pi is ready for use.

Install the workshop software by opening a terminal on the Pi and clone this repositry to your own local system with :

git clone https://github.com/zeno4ever/zip_pi_doorbell

copy 'config.py.example' to 'config.py' with the 'cp' command : cp config.py.example config.py

Fill in the parameters you got in the steps from telegram.

telegram_token - Telegram bot API token telegram_chat - Telegram channel id userid - Your Pi's (home directory) name url - For the jitsi change the url part 'your_channel' to your own variation

In the script 'doorbell.py' and 'doorbell.desktop' you have to fill in your own home directory if you user name is different then 'pi'. Look for '/home/pi' and replace 'pi' with your own user name.

We use telegram messages to give you realtime update that someone is at the door.

First create a new private telegram channel where you want to receive the door notifications. If you want to hear updates enable (sound) notifications for this channel.

Get your personal bot token via these steps and save the bot token.

Add you telegram bot as an admin to your channel.

Type and send something in your new channel. Then, navigate in your webbrowser to the following url: https://api.telegram.org/bot/getUpdates . Replace with your bot token. You should see some JSON-related information about your bot, including your sent message. Listed under 'chat', there is a variable called 'id' with a long number with a dash in front of it. This is your channel id, including the dash.

We included a 'test_telegram.py' script to test and find the right channel number. Edit config.py first to include your bot token.

We use the header to add some additional hardware to the pi. See Raspberry documentation for more informations about the Pi GPIO header pins.

• Pin 6 - GND
• Pin 8 - GPIO14

• Pin 37 - GPIO26
• Pin 39 - GND

You use the flex cable to connect your camera to your pi, follow the instructions on their site. The rasberry pi automatically recognises this.

Your can see if the camera works with command : libcamera-hello

This should give you a preview of the camera (video) picture for 5 seconds.

Test the sound with 'aplay dingdong.wav', you should hear the doorbell sound. If you hear noting check the audio volumes with command 'alsamixer'

Start firefox and go to the jitsi you configured. Adjust camera and sound setting for jitsi, so next time the system knows what to use.

Final test, in the terminal on the desktop start the script and press the button.

You should hear the dingdong bell, get a message in telegram and the jitsi channel should be joint by the door.

Create the autostart directory this will not exist on a new system.

mkdir ~/.config/autostart

In the 'doorbell.desktop' change the paths to the directory where to script is. Move file 'doorbell.desktop' to ~.config/autostart/

mv doorbell.desktop ~/.config/autostart/

In the 'doorbell.desktop' is a path to your homedirectory. Default we assume this is user 'pi', if this is diferent, change it accordingly.

Reboot the pi and wait until its fully booted. press the button and enjoy your own DIY smart doorbell.

If you can't hear sound probaly your volume is to low. You can change this via desktop upper right speaker symbol. Alternative you can use the 'alsamixer' command.

Instead of a USB sound card you can use - Adafruit STEMMA Speaker (ada3885) and 3 pin JST cable with female pin connectors.

• Pin 6 - GND
• Pin 4 - +5V
• Pin 12 - GPIO18 / signal

Add the following lines to the config.txt file after the 'dtparam=audio=on' line.

audio_pwm_mode=2
dtoverlay=audremap,pins_18_19

This will set the audio output to the header pins. Reboot the pi to make this active.