Golioth Trashcan Monitor Reference Design

This reference design outlines a solution for remotely monitoring trash receptacles, specifically tailored for municipalities looking to optimize waste management. The system is designed to track and report the fill levels and conditions of various trash bins at regular, programmable intervals. This data can help municipalities make informed decisions about waste collection, reducing unnecessary pickups and improving efficiency.

A key feature of this design is its emphasis on long battery life, as the monitoring device is intended to be powered by batteries. To maximize operational efficiency, the device is engineered to minimize power consumption, ensuring that the batteries can last as long as possible before needing replacement or recharge. This makes it a cost-effective and low-maintenance solution for cities aiming to streamline waste collection while conserving resources. Additionally, the design supports adaptability, allowing customization of reporting intervals to suit the specific needs and constraints of the municipality.

Business use cases and hardware build details are available on the IoT Trashcan Monitor Project Page.

This repository contains the firmware source code and pre-built release firmware images.

Supported Hardware

• Nordic nRF9160-DK
• Golioth Aludel Elixir

Additional Sensors/Components

• ST VL53L0X Time-of-Flight ranging sensor
• ST LIS2DH12 MEMS digital output motion sensor
• Bosch BME280 digital humidity, pressure, and temperature sensor

Golioth Features

This app implements:

• Device Settings Service
• Remote Procedure Call (RPC)
• Stream Client
• LightDB State Client
• Over-the-Air (OTA) Firmware Upgrade
• Backend Logging

Settings Service

The following settings should be set in the Device Settings menu of the Golioth Console.

• LOOP_DELAY_S Adjusts the delay between sensor readings. Set to an integer value (seconds).

  Default value is 60 seconds.

• TRASH_CAN_HEIGHT_MM Set the trashcan height. Set to an integer value (millimeters).

  Default value is 500 millimeters.

Remote Procedure Call (RPC) Service

The following RPCs can be initiated in the Remote Procedure Call menu of the Golioth Console.

• get_network_info Query and return network information.

• reboot Reboot the system.

• set_log_level Set the log level.

  The method takes a single parameter which can be one of the following integer values:

  • 0: LOG_LEVEL_NONE
  • 1: LOG_LEVEL_ERR
  • 2: LOG_LEVEL_WRN
  • 3: LOG_LEVEL_INF
  • 4: LOG_LEVEL_DBG

Time-Series Stream data

Sensor data is periodically sent to the following endpoints of the LightDB Stream service:

• weather/gas/co2: Carbon Dioxide(ppm)
• weather/gas/voc: Volatile Organic Compounds (ppb)
• weather/humidity: Humidity (%RH)
• weather/pressure: Pressure (kPa)
• weather/temp: Temperature (°C)
• VL53/distance: Distance to waste (mm)
• VL53/fill level: Trashcan fill level (%)
• accel/x: Acceleration X-axis (m/s²)
• accel/y: Acceleration Y-axis (m/s²)
• accel/z: Acceleration Z-axis (m/s²)

{
  "sensor": {
    "distance": {
      "distance": 0.037,
      "level": 100,
      "prox": 1
    },
    "gas": {
      "co2": "sensordead",
      "voc": "sensordead"
    },
    "imu": {
      "accel_x": 0.114912,
      "accel_y": -0.229824,
      "accel_z": -9.805824,
      "orientation": "upright"
    },
    "weather": {
      "humidity": 43.390625,
      "pressure": 101.194925,
      "temp": 26.56
    }
  }
}

If your board includes a battery, voltage and level readings will be sent to the battery path.

Note

Your Golioth project must have a Pipeline enabled to receive this data. See the Add Pipeline to Golioth section below.

OTA Firmware Update

This application includes the ability to perform Over-the-Air (OTA) firmware updates. To do so, you need a binary compiled with a different version number than what is currently running on the device.

Note

If a newer release is available than what your device is currently running, you may download the pre-compiled binary that ends in _update.bin and use it in step 2 below.

1. Update the version number in the VERSION file and perform a pristine (important) build to incorporate the version change.

2. Upload the build/app/zephyr/zephyr.signed.bin file as a Package for your Golioth project.

   • Use main as the package name.
   • Use the same version number from step 1.

3. Create a Cohort and add your device to it.

4. Create a Deployment for your Cohort using the package name and version number from step 2.

5. Devices in your Cohort will automatically upgrade to the most recently deployed firmware.

Visit the Golioth Docs OTA Firmware Upgrade page for more info.

Add Pipeline to Golioth

Golioth uses Pipelines to route stream data. This gives you flexibility to change your data routing without requiring updated device firmware.

Whenever sending stream data, you must enable a pipeline in your Golioth project to configure how that data is handled. Add the contents of pipelines/cbor-to-lightdb.yml as a new pipeline as follows (note that this is the default pipeline for new projects and may already be present):

1. Navigate to your project on the Golioth web console.
2. Select Pipelines from the left sidebar and click the Create button.
3. Give your new pipeline a name and paste the pipeline configuration into the editor.
4. Click the toggle in the bottom right to enable the pipeline and then click Create.

All data streamed to Golioth in CBOR format will now be routed to LightDB Stream and may be viewed using the web console. You may change this behavior at any time without updating firmware simply by editing this pipeline entry.

Local set up

Important

Do not clone this repo using git. Zephyr's west meta tool should be used to set up your local workspace.

Install the Python virtual environment (recommended)

cd ~
mkdir golioth-reference-design-trashcan
python -m venv golioth-reference-design-trashcan/.venv
source golioth-reference-design-trashcan/.venv/bin/activate
pip install wheel west ecdsa

Use west to initialize and install

cd ~/golioth-reference-design-trashcan
west init -m [email protected]:golioth/reference-design-trashcan.git .
west update
west zephyr-export
pip install -r deps/zephyr/scripts/requirements.txt

Building the application

Build the Zephyr sample application for the Nordic nRF9160 DK (nrf9160dk_nrf9160_ns) from the top level of your project. After a successful build you will see a new build directory. Note that any changes (and git commits) to the project itself will be inside the app folder. The build and deps directories being one level higher prevents the repo from cataloging all of the changes to the dependencies and the build (so no .gitignore is needed).

Prior to building, update VERSION file to reflect the firmware version number you want to assign to this build. Then run the following commands to build and program the firmware onto the device.

Warning

You must perform a pristine build (use -p or remove the build directory) after changing the firmware version number in the VERSION file for the change to take effect.

$ (.venv) west build -p -b nrf9160dk/nrf9160/ns --sysbuild app
$ (.venv) west flash

Configure PSK-ID and PSK using the device shell based on your Golioth credentials and reboot:

uart:~$ settings set golioth/psk-id <my-psk-id@my-project>
uart:~$ settings set golioth/psk <my-psk>
uart:~$ kernel reboot cold

External Libraries

The following code libraries are installed by default. If you are not using the custom hardware to which they apply, you can safely remove these repositories from west.yml and remove the includes/function calls from the C code.

• golioth-zephyr-boards includes the board definitions for the Golioth Aludel-Mini
• zephyr-network-info is a helper library for querying, formatting, and returning network connection information via Zephyr log or Golioth RPC

Have Questions?

Please get in touch with Golioth engineers by starting a new thread on the Golioth Forum.