Doorbell Chime

This project describes how to create an electronic doorbell chime using a Raspberry Pi Zero WH running Raspberry Pi OS Lite, an Audio Hat and a step down voltage converter. No soldering is required. And it is a relatively easy project.

The electronic chime fits in a mechanical chime case and uses the wiring for the chime to power the Raspberry Pi. The Audio Hat comes with two speakers.

I made the chime work with an Arlo Doorbell, but it should be compatible with any Smart Doorbell supported by IFTTT, just change the trigger in IFTTT

Parts

• • Raspberry Pi Zero WH (with Headers)

    • 8GB MicroSD card

    • Low profile heat sink with fins 14mm x 14mm x 4mm (not the gold flat ones, that don't dissipate heat effectively)

  • Old Mechanical Wired Doorbell Chime with 16 Volt Doorbell Transformer

  • Waveshare LM8960 Audio Hat

  • 16V AC too 5V DC step down converter

    • KNACRO AC-DC to DC Converter AC 16-28V DC 9V 12V 24V 36V 8-40V Step Down to 5V 3A 15W Power Supply Module

    • If you have a 24V transformer, then get 24V AC to 5V DC step down transformer

  • Wiring twist nuts in various sizes

Tools (all reusable)

drill

power tool to remove excess plastic from mechanical chime base

voltmeter

5V Raspberry Pi Power Supply (temporary, used during setup)

thumbtacks

CAUTION: Speakers have very large magnets and some small magnets. Both are capable of erasing a microSD Card, destroying a raspberry pi and the FM Receiver. Keep the components far away from the magnets.

Step 1. Setup Raspberry Pi Zero WH

• • In Step 1 when imaging, Choose Raspberry PI OS Lite (32 Bit), but it doesn't really matter which Raspberry Pi OS you choose

  • Since this is in effect an embedded system, the desk top is not needed

  • In Step 1, be sure to setup SSH and Wi-Fi

  • Use a 5V Raspberry Power Supply until it is replaced with the step down converter

  • Don't put it in a case, this is done below

Step 2. Add Waveshare WM8960 Audio Hat

Poweroff Raspberry Pi by doing the following:

$ sudo shutdown -h 0

Pull the power cable frrom the Raspberry Pi

Put the hat on the Raspberry Pi.

Put the power back into the Raspberry Pi

Open terminal window and login

Install the Audio Hat Driver driver

$ sudo apt install git -y

$ git clone https://github.com/waveshare/WM8960-Audio-HAT

$ cd WM8960-Audio-HAT

$ sudo ./install.sh

$ sudo reboot

Check if driver is installed

$ sudo dkms status

wm8960-soundcard, 1.0, 5.10.63+, armv6l: installed (original_module exists)

Get doorbell sound, You can use any doorbell sound you want.

$ wget https://github.com/dumbo25/electronic-doorbell-chime/raw/main/dingDongChime.wav

aplay shoould be installed with Raspberry Pi OS. If not, use:

$ sudo apt install alsa-utils

Play the doorbell

$ sudo aplay -Dhw:0 dingDongChime.wav

If volume needs to be raised or lowered use:

$ sudo alsamixer

Step 3. Get Software and Test

If noot logged into Rasppbery POI, Open terminal window and login

bottle.py is a. very simple, fast web server

$ wget https://bottlepy.org/bottle.py

Get chime.py

$ wget https://raw.githubusercontent.com/dumbo25/electronic-doorbell-chime/main/chime.py

Check if it works

On the Raspberry pi run the command

$ sudo python chime.py

Open a browser, and enter in the URL box:

http://♣your-raspberry-pi's-ip-address♣:8081/

The doorbell sound should play

Step 4.Find your Gateway's Public IP Address

To view my ISP's gateway, I enter 192.168.1.254 in a browser's URL. To find the gateway's public IP address, I navigate to the Broadband, and Status tabs. The Public IP address is Broadband IPv4 Address.

Step 5. Port Forwarding

In general, your gateway should block all in-coming requests.

Use HTTP and port forward to 8081 or another poort of your choosing

NOTE: When I port forwarded 8081, my gateway said port forwarding might break my internet service. It did not. But the chime rang when no one pressed the doorbell. I assume this was either my ISP sending the gateway packets or someone reading this guide and sending me doorbell presses. So, I changed to a random port. This required a change to Port Forwarding, chime.py and the IFTTT applet. You should pick a port in the user or registered port range:

• Ports 0–1023 – system or well-known ports

• Ports 1024–49151 – user or registered ports

• Ports 49152–65535 – dynamic / private / ephemeral ports

Step 6. Arlo Doorbelll and IFTTT

If-This-Than-That is a web-based service allowing events on one device to trigger actins for another device. IFTTT is a simple way for devices to communicate.

If you don't have one, create either a free or paid account on IFTTT

Create an applet

Click Create button

On If-This, click Add

Click on Arlo icon

Click Detects Button Press

Add Your Arlo Account

Your Arlo Account and Doorbell should appear

Click Create Trigger

On Then-That click Add

Select Webhooks

Click Make a web request

Enter URL = http:<public-ip-address>:<port>/

Method = Get

Content = text/plain

Click Create action

With chime.py running, press the Arlo doorbell and see if the doorbell plays the wav file.

Step 7. Create a service to start chime.py on reboot

The directions are contained within the script

Or download the script using:

$ sudo wget https://raw.githubusercontent.com/dumbo25/electronic-doorbell-chime/main/chime.service

$ sudo chown root:root chime.service

$ sudo cp chime.service /lib/systemd/system/.

Step 8. Start chime.py automatically using

After any changes to /lib/systemd/system/chime.service:

$ sudo systemctl daemon-reload

$ sudo systemctl enable chime.service

$ sudo systemctl start chime.service

$ sudo reboot

Wait 2-3 minutes for reboot to complete, and then log back into Raspberry Pi

Ensure the chime.service in systemd is enabled and running:

$ systemctl | grep running | grep chime

$ systemctl status chime.service -l

If there are any issues with starting the script using systemd, then examine the journal using:

$ sudo journalctl -u chime.service

Press the Arlo Doorbell to ensure it rings

Step 9. Shutdown Raspberry Pi

Shut down the Raspberry Pi using the command.

$ sudo shutdown -h 0

Unplug the microUSB power to the Raspberry Pi

Step 13. Attach parts to Chime's Back

The step down converter goes in the chime's junction box and not on the chime's back

Remove the micro USB from the Raspberry Pi, and thread the micro USB through the chime's back

Place the Raspberry Pi and speakers so everything fits. Mark and drill holes for the parts

Use bolts, nuts and standoffs to attach the Raspberry Pi and Speakers

Thread the micro USB through the backside of the chime's back

Put the step down converter in the junction box

Attach the chime's back to the wall

Insert the micro USB into the Raspberry Pi

Put the chime's cover on

Add key

Where do I find my Webhooks key?

Go to Webhooks service page and click Documentation.

Change the call to be

https://maker.ifttt.com/trigger/{event}/json/with/key/<your-key>

port forward 443 and not 80

to Edit ifttt applet, goto ifttt.com, select an applet, then click the settings button

Background:

I have a 16V AC mechanical doorbell chime, and an Arlo wired video doorbell. Everything on the Arlo doorbell and app works fine except the Arlo Doorbell cannot "ring" a mechanical chime.

The Arlo App settings are correct: Traditional Chime = Mechanical, Silent Mode = Off, Bypass Mode = O, there are no Arlo temperature warnings, Power at chime = 16V AC, Power at Arlo doorbell = 16V AC.

I've contacted Arlo support multiple times both by calling and emailing.

I paid an electrician to check the wiring.

I bought a second Arlo after frying the first one by doing a factory reset.

Do NOT do a factory reset on the Arlo Doorbell. I did this on the first Arlo Doorbell and it died.

And, I tried three different mechanical chimes and two different transformers.

The mechanical chime works until the Arlo PowerKit is inserted, and then the chime doesn't make a sound.

I tried bypassing the Power Kit.

So, with the two Arlo Doorbells, the electrician, multiple chimes and multiple transformers, I've spent about $500 trying to get a supported mechanical chime to work with an Arlo doorbell without success.

References:

need to follow format for references

• <site>, <author>, <webpage with link>, <description>

• WAVESHARE, WM8960 Audio Hat, technical description of audio hat with installation instructions

• bottlepy.org, bottlepy.org, developer site, download and installation

• indianbeantree, Controlling Anything With Alexa And Raspberry Pi, describes Alexa, IFTTT to control Raspberry Pi

• Circuit Basics, How to Control the Raspberry Pi's GPIO pins remotely, uses Alexa, IFTTT to control Raspberry Pi

• If-This-Than-That, IFTTT, web based utility to trigger an action when another action occurs

Alternative Solution 1:

A simple workaround is to create a routine to have an Amazon Echo play a doorbell sound when the Arlo Doorbell button is pushed.

• Open Amazon Alexa App on smartphone

• Go to Home, 3 line Hamburger Menu, Routines, and then +

  • Enter Routine Name = Arlo doorbell press

  • When this happens, Smart Home, doorbell, Doorbell, when doorbell is pressed

  • Scroll to Sounds, Bells and buzzers, select one

Alternative Solution 2:

An alternative is to connect the Arlo Doorbell to multiple Echos and have the chime play on whichever Echos you want.

• • Open Amazon Alexa App on smartphone

  • Click Devices icon

  • Click All Devices

  • Select Arlo Doorbell

  • On the Settings Page

    • Enable Doorbell Announcemeents

I prefer this approach, however, I don't want Alexa to say anything, just ring the bell (Post on Arlo Community)