Chicken Door / Chicken Cam

An automated door for our chicken coop, plus a Raspberry Pi that livestreams two cameras to the browser using WebRTC.

Block diagram

How it works

The main goal of this project is to automatically open the door in the morning (using a gear motor), and to close it at night.

In the controller, a combination of RTC and ambient light sensor is used:

• In the morning, the door will open if the OPENING_LUX_THRESHOLD is passed, but not before EARLIEST_OPENING_TIME.
• If LATEST_OPENING_TIME is reached, the door will open even if the OPENING_LUX_THRESHOLD has not yet been reached.
• Once the door is open, it will not close again before EARLIEST_CLOSING_TIME is reached.
• After EARLIEST_CLOSING_TIME, the door will close once the ambient light falls below the specified CLOSING_LUX_THRESHOLD.
• If the CLOSING_LUX_THRESHOLD is not reached at LATEST_CLOSING_TIME, the door will close anyways.

To detect an open or closed door, reed switches are used.

The controller is connected via USB / serial to a Raspberry Pi. This Raspberry Pi is used for streaming two webcams to a website (an outdoor webcam and an indoor infrared night-sight webcam).

Additionally, the Raspberry Pi sends out Threema notifications whenever the door status changes (or if an error occurs). For this, the observer-service is used.

Firmware: State machine

┌───────┐                         ┌─────┐
│Initial├────────────────────┐    │Error│
└───────┘                    │    └─────┘
   │                         │
   ▼                         │
┌──────┐     ┌──────────┐    │
│Closed├────►│PreOpening│    │
└──────┘     └───────┬──┘    │
   ▲                 │       │
   │                 ▼       │
┌──┴───────┐       ┌────┐    │
│PreClosing│◄──────┤Open│◄───┘
└──────────┘       └────┘

• Initial: The state when turned on. The controller will transition to the "Open" or "Closed" state depending on the sensor readings.
• Closed: Waiting for EARLIEST_OPENING_TIME
• PreOpening: Waiting for either OPENING_LUX_THRESHOLD or LATEST_OPENING_TIME
• Open: Waiting for EARLIEST_CLOSING_TIME
• PreClosing: Waiting for CLOSING_LUX_THRESHOLD or LATEST_CLOSING_TIME
• Error: Reachable from any state when something goes wrong (e.g. reading a sensor)

If the firmware is in non-error state, the blue LED will toggle every second. If it's in error state, the LED will remain on.

Firmware: Testing

To run unit tests:

cargo test --target x86_64-unknown-linux-gnu --tests

Firmware: Flashing

cd firmware
cargo flash --connect-under-reset --chip STM32F411CEUx --release

Firmware: Serial Terminal

To open a serial connection:

python -m serial.tools.miniterm /dev/ttyACM0 9600

Then type ? to see the help.

Chicken Cam

In addition, the rpi-image directory contains a buildroot based Linux and all configuration necessary to livestream two cameras (an USB webcam and a raspi cam) to the web browser using WebRTC (backed by Janus as streaming server).

To build the Raspberry Pi image:

cd rpi-image
./build.sh