iamsingularity/klocka

Smart Doorbell? Pi-Powered "Smart" Doorbell!

Klocka

Demo

Testimonials

I think this captures the essence of the "IoT" trend - take a function accomplished by a simple existing device, and do it using mindboggling amounts of hardware and software complexity.

-- userbinator

I doubt this dude is trying to "disrupt" the doorbell industry.

-- riebschlager

But yes, it's strongly in the Rube Goldberg territory.

-- viraptor

Is this a joke?

-- eng_monkey

This is awesome, you should start a Kickstarter!

-- No one, ever. Hopefully.

Motivation

Well, I recently got an awful (cheap) doorbell from Clas Ohlson. As it turns out, my AA batteries wouldn't even fit inside the receiver, and the speaker sounds awful. But, what if I could hook up the receiver to a RPi instead? Hmm...

Usage

When compiled, this should create a single self-contained binary, which listens on port 8080 for the web interface and binds to the GPIO pin 22. To register your browser, go to http://localhost:8080/ and approve the permission request. If you want to be able to register a remote device, you'll need to put a SSL terminating reverse proxy in front of this, since browsers for some reason don't support push notifications from unencrypted websites.

To make things worse, at least Chrome doesn't like loading workers from untrusted domains, so even a self-signed certificate won't work out of the box. To get around this, you'll need to download the certificate to your browser and whitelist it. Alternately, sign it through a service like Let's Encrypt, but that requires you to expose the service to the public, which probably isn't a great idea...

Limitations

At least on Chrome and Firefox for desktop, the ringtone doesn't trigger unless the page is open. This should change when/if browsers start supporting the audio parameter for notifications...

Browser support

Currently only Google Chrome and Firefox are supported. No other browsers currently implement the Push API required for this to function.

Customizing

If you don't want to make it bind any GPIO pins, set the environment variable KLOCKA_TRIGGER to FD, which will make it trigger on newlines in stdin instead. If you want to change the pin it uses (BCM 22 by default), change GPIO_PIN in server/src/trigger/mod.rs. The port for the web UI is set as WEB_PORT in server/src/main.rs.

Building (physically)

Use a multimeter to find out which cable to the LED carries the signal (you might want to take a picture). Desolder the cables to the battery enclosure, speaker, and LED. Solder jumper cables to where both cables to the battery enclosure went, as well as for the signal that went to the LED. Connect the two power cables to a 3v3 pin and a ground pin on the Pi (the one that went to the positive battery pole should go to the 3v3 pin), and the LED cable to BCM pin 22 (physical pin 15).

Building (client)

In web-client/manifest.json, change gcm_sender_id to your Google project ID.

Building (server)

Create a file called server/gcm_key.txt containing ONLY your Google Cloud Messaging key. Afterwards you should be able to cargo run (from the server directory).

Cross-compiling for the RPi 2/3

You'll need:

• A rustc target (install with rustup target add armv7-unknown-linux-gnueabihf)
• A GCC for the target platform (on Arch, this means arm-unknown-linux-gnueabihf from the AUR)

(Note: Currently the AUR's ARM version of GCC is broken, you'll need to add --std=gnu++03 to $CXXFLAGS in the PKGBUILD for GCC 6 to want to build GCC 5)

First, sync git submodules and run server/openssl-build-arm.sh to build OpenSSL. Then, run server/crossbuild-arm.sh to compile!