B-NAHL Hive Monitor

I - Story

A - Introduction

Beekeeping faces several major challenges threatening the survival of bee colonies. Colony collapse disorder (CCD) causes abnormally high mortality, weakening hive balance. Biological threats, such as the Varroa mite and the Asian hornet, exert constant pressure on bees. Furthermore, pollution and the intensive use of pesticides, particularly neonicotinoids, weaken their health and foraging ability. Climate change alters the availability of floral resources, disrupting their diet. Finally, hive theft forces beekeepers to increase surveillance and security of their facilities.

B - Features

Our prototype measures the following hive characteristics:

• Temperature and humidity inside the hive using three different sensors.
• Temperature, humidity, and brightness of the hive's outdoor environment.
• Battery level of the system, recharged by a solar panel and hive weight.
• Queen presence using AI-powered sound analysis (unfinished but planned).

II - Sensors

A - Temperature and humidity sensors

Our system uses a combination of temperature and humidity sensors to ensure accurate and reliable monitoring of the beehive’s environment. Inside the hive, we have two DS18B20 sensors dedicated to measuring temperature and one DHT22 sensor that provides both temperature and humidity data. To protect the DHT22 from damage, it will be encapsulated in a custom 3D-printed enclosure, ensuring durability while maintaining accurate readings. This redundancy enhances reliability, allowing the system to remain functional even if one sensor fails. For external conditions, we use an SHT31 sensor, which measures both temperature and humidity outside the hive, providing valuable insights into the environmental factors affecting the colony.

B - Brightness sensor

The BH1750 light sensor is positioned above the hive, alongside the solar panel, inside a transparent enclosure that allows light to pass through. This sensor enables us to remotely monitor the number of sunlight hours, providing valuable insights into the hive’s exposure to natural light. This data can help correlate environmental conditions with bee activity and energy generation from the solar panel.

C - Battery and solar panel

The system is powered by a 3.7V 2000mAh LiPo battery, which is recharged using a solar panel. The charging process is managed by a LiPo Rider Pro board, which regulates the energy input and provides a stable 5V DC output to power the components. This setup ensures the system remains autonomous and operational even in remote locations, reducing the need for manual intervention.

D - weight sensor

The scale sensor (equivalent to Bosch H40A) is placed underneath the hive to continuously monitor its weight. It is connected to an HX711 load cell amplifier, which ensures accurate weight measurements. This data provides valuable insights into honey production, bee activity, and colony health. Additionally, sudden weight changes can help detect potential hive theft, allowing for quick intervention if necessary.

III - Full System

A- PCB design

The entire system was designed using KiCad to model the electrical circuit, which was first tested on a Labdec prototyping board. Given the number of sensors involved, this testing phase was crucial to ensure proper functionality and compatibility. Once validated, we finalized the PCB schematic, which was then printed and soldered. This structured approach allowed us to refine the design, optimize connections, and ensure a reliable and efficient final assembly.

B - Production of the box

To ensure the durability and waterproofing of our system, we encapsulated all components inside a PVC waterproof enclosure. This robust housing protects the electronics from environmental factors while keeping the system reliable over time. The sensor wiring is neatly organized through seven dedicated cutouts in the enclosure, allowing for secure and structured cable management:

• On/Off Button
• Under the hive: Weight sensor (original cable)
• Top of the hive: Solar panel + light sensor (6 wires, 1.5m-2m cable)
• Inside the hive: DHT22 + 2x DS18B20 (5 wires, 1m cable)
• Outside the hive: SHT31 (3 wires, 20-30cm cable)
• Inside for AI processing: Nano 33 BLE Sense (4 wires, 50cm cable)
• LoRa SNOC Antenna