Waste bins are everywhere in our society. They may be large commercial dumpsters behind your favorite restaurant, remote animal-proof bins in a provincial park, or the typical municipal garbage or recycling bin. Governments and businesses are responsible for servicing these bins when they approach or achieve their capacity. To reduce waste management operational costs and to gather insights on better public infrastructure planning, we are proposing to place small battery-powered sensors in the waste bins to sense the level of material in them. The sensors each communicate how full its bin is using a low-power public radio network to inexpensive centralized gateways which have an urban range of many kilometer. By measuring these levels, we are able to improve servicing path decisions for waste management staff, avoid situations such as overflowing bins and potential resultant littering and eliminate unnecessary servicing of empty bins. These benefits will save time, money and avoid problematic situations for those that deploy our solution.
How it works:
By utilizing the LoRa Technology stack and an ultrasonic sensor paired with a microcontroller unit, our product measures waste-bin levels and reports the values to centralized server(s) via LoRaWAN. The level sensor has a range of 15cm-500cm and is low power. The sensor requires under 8ma for the 10µs pulse which sends 8 40khz pulses out to measure the bin level. The microcontroller unit utilizes a deep sleep mode to reduce power significantly when not reading bin level or sending data to the centralized server(s). The majority of the time the device will only be drawing 70µA in deep sleep mode. Additionally, the LoRa chip is also battery efficient which means our device does not have any strenuous battery loads. With a 3000mAh battery we have conservatively estimated battery life to be greater than 2.5 years. The sensors communicate their readings via the LoRaWAN protocol to our LoRaWAN gateways which have an urban range of 7km, and ~100km of line of sight conditions.
What makes it novel:
By utilizing LoRa technology we steer clear of expensive alternatives such as WiFi which lacks range, and cellular data transmission which requires a relatively power-hungry sim card module and costly data plans for each node. Compared to LoRa, cellular data does not scale well because its radios and SIM cards are more expensive to integrate into a PCB design and require more energy per data message transmitted since they use more complex waveforms and have a higher modulation rate. This is especially true for applications in Canada which has the highest data plan rates in the world. Thus, WiFi and cellular data sensor connectivity is better suited for applications that have larger data rates and shorter battery life than it is for waste bin level sensing, which is well-suited to low-power radio connectivity.
Features of the gateway and end nodes include:
Enables GPS-free, low power tracking applications
Reduces costs three ways: infrastructure investment, low operating expenses and low end-node sensor cost
Improved global interoperability speeds adoption and roll out of LoRaWAN-based networks and IoT applications
Protocol designed specifically for low power consumption devices extending battery lifetime up to 20 years and enabling remote self contained systems.
Single base station provides deep penetration in dense urban/indoor regions and is able to connect rural areas up to 50 kilometers away
Embedded end-to-end AES128 encryption
Supports millions of devices per LoRa gateway which enables many different use cases serving many customers.
Our prototype is built with off the shelf components and a custom 3d printed housing. For the production versions we plan on producing the product housing with injection molded plastic and it will be approximately 40% the size of the prototype (45cm2) as seen in the video. We plan to modify the development board to reduce its size and remove the on-board pins and replace them with wired connections to the sensors. We will also be removing the on-board AA battery, as we will be sourcing a larger and more reliable li-ion 18650 battery cells to be mounted directly into the plastic case. Electric components will be sourced directly from the supplier to be sent to an assembly facility that is nearby.
Cost of sensor device: $13 USD
Cost of gateway: $450 USD
Where it's applied:
The level sensors can be placed in public garbage cans that exist around a city in both outdoor and indoor locations. Business and company buildings will want to utilize these sensor nodes to be able to better serve their customers and staff that use the facilities. Waste bin levels that exist within bathrooms, private rooms, or lobbies can be monitored to provide better maintenance services. The gathered data is accessible via a web platform and notifications can also be configured to be directly sent via a messaging service to waste management staff and/or managers. The data also provides stakeholders with metrics relevant to how trash is being accumulated and managed in their waste bins.