Golioth Trashcan Monitor Reference Design

Overview

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.

Supported Hardware

This firmware can be built for a variety of supported hardware platforms.

Important

In Zephyr, each of these different hardware variants is given a unique "board" identifier, which is used by the build system to generate firmware for that variant.

When building firmware using the instructions below, make sure to use the correct Zephyr board identifier that corresponds to your follow-along hardware platform.

Follow-Along Hardware

Hardware	Zephyr Board	Follow-Along Guide
	nrf9160dk/nrf9160/ns	nRF9160 DK Follow-Along Guide

Custom Golioth Hardware

Hardware	Zephyr Board	Project Page
	aludel_elixir/nrf9160/ns	Trashcan Monitor Project Page

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

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 Aludel Elixir 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.

Important

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

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.

Golioth Features

This app currently implements Over-the-Air (OTA) firmware updates, Settings Service, Logging, RPC, and both LightDB State and LightDB Stream data.

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.

LightDB Stream Service

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)

Battery voltage and level readings are periodically sent to the following battery/* endpoints:

• battery/batt_v: Battery Voltage (V)
• battery/batt_lvl: Battery Level (%)

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

Hardware Variations

This reference design may be built for a variety of different boards.

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.

Golioth Aludel Elixir

This reference design may be built for the Golioth Aludel Elixir board. By default this will build for the latest hardware revision of this board.

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

To build for a specific board revision (e.g. Rev A) add the revision suffix @<rev>.

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

OTA Firmware Update

This application includes the ability to perform Over-the-Air (OTA) firmware updates:

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 an artifact for your Golioth project using main as the package name.
3. Create and roll out a release based on this artifact.

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

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