Connected Beehive - Liberate Beekeepers

Introduction

Traditional beekeepers usually have to go to the hives frequently to obtain the status of the bee colony:

• whether the queen bee is lost,
• whether there is a wasp attack,
• whether the hives are stolen,
• the production of honey……

Our professor at Sorbonne University, Mr. DOUZE, is an amateur beekeeper. Since the hives are far away from his home, he suffers from frequent travel between his home and his beehive. In order to save the time and energy of beekeepers so that they can get information and alerts about beehives and bee colonies without leaving home, we created the connected beehive that meets the following needs：

• Temperature detection inside the beehive (using DS18B20 and SHT20)
• Humidity detection inside the beehive (using SHT20)
• Sound spectrum analysis inside the beehive （using Microphone）
• Temperature and Humidity detection outside the beehive (using DHT22)
• Weight sensor
• Fall detection (using Accéléromètre - MMA8452)
• Wind direction and wind speed detection (using wind vane LEXCA002)
• 100% autonomous system (using Li-Ion battery 3.7 V 1050 mAh and SOL3W solar cell)
• Long-distance data transmission (using Sigfox BRKWS01)
• Visual data display and warning system (using Ubidots)

Breadboard prototype

Implementation

Sensor location

Code

We implement all sensors through “mbed”. You can view the complete code in the attachment.

• Température & Humidité - SHT21

Library used : Graeme Coapes, décembre 2012

Fonctions :

getTemperatureINT_SHT() (readTemp())
getHumidityINT_SHT() (readHumidity())

• Température & Humidité - DHT22

Library used : Wimpie, juillet 2012, Belgique

Fonctions :

getTemperatureEXT() (ReadTemperature())
getHumidityEXT() (ReadHumidity())
readData()
Dht_err (détections d’erreurs)

• Température - DS1820

Library used : Zoltan Hudak, juin 2020, Slovaquie

Fonctions :

readtempDS()
startConversion()
read()

• Microphone

We perform spectrum analysis on the sound signal collected by the microphone to infer the activity and health status of the colony (we will introduce it in detail below)

• Accéléromètre - MMA8452

Library used : Craig Evans, mars 2015, Royaume-Uni

Fonctions :

getAccel()

• Wind Vane - LEXCA003

We set 8 directions : 0-N ; 1-NE ; 2-E ; 3-SE ; 4-S ; 5- SO ; 6-O ; 7- NO.

It can also detect the speed of the wind by counting the number of turns in 1 second.

• Weight sensor

We weigh the beehive in the school and subtract its weight from the value obtained by the weight sensor to get the net weight. This process is implemented in the code.

• Batterie Accu Li-Ion

We use a voltage divider to calibrate the battery percentage.

Data Analysis

Obtaining beehive information is only the first step. What is more important is to judge the health and activity status of the bee colony based on the obtained data, and notify the beekeeper when an abnormality occurs. To this end, we have done a lot of research to ensure that our smart beehive can make correct warnings based on the data obtained by the sensors. Of course, an experienced beekeeper can also set the trigger conditions for the warning according to his own needs.

• Sound

The sound research took the longest time. We read many papers, tried to find the relationship between different activities and sound frequencies, and produced the following table:

We set up alerts in ubidots based on the above table (mentioned below). Since these are summarized based on published papers, we will verify whether the behavior and sound frequency correspond in actual use, and fine-tune and optimize the trigger conditions in the later stage.

• Temperature

Beehive temperature is really critical to good honey and bee health. The temperature in the beehive is between 33 and 36°, indicating that the colony keeps larvae normally, if the brood, the baby bees, get hotter than 36° they will die. In addition, since 20% to 30% of the bee colony cannot survive the winter, we can also judge whether the colony is alive by the temperature inside the beehive. If the temperature is too low, the colony is dead.

• Humidity

Humidity of the brood nest is important for the overall fitness of a honeybee colony. Numerous studies have demonstrated that either high or low levels of humidity affect the health of the brood and adult bees, either directly, for example at levels below 50% relative humidity in the brood cells no eggs hatch (Doull 1976), this being particularly relevant for small nuclei, or indirectly by favouring the development of pathologies.

• Weight

Beekeepers are most concerned about the production of honey. Through the weight, we can know how much honey the bee colony produces and how much the colony expands.

• Wind Vane

Wind speed has a lot of influence on bees. If the wind is strong, it may cause the flowers and branches of nectar plants to collide, cause damage to the flowers, and damage the source of honey. In addition, strong winds will speed up the drying of nectar, which make it harder for bees to collect nectar. The lack of honey sources for bees will naturally affect honey production, not to mention the windy weather itself will affect the flight of bees.

• Acceleration

The acceleration sensor is directly plugged into the PCB board to detect whether the beehive is overturned or moved or stolen by humans.

Connectivity and Interface

• Sigfox

In order to transmit the data of the connected beehive to the client in real time while ensuring low power consumption, we use sigfox.

Sigfox is a French global network operator founded in 2010 that builds wireless networks to connect low-power objects such as electricity meters and smartwatches, which need to be continuously on and emitting small amounts of data.The existing standard for Sigfox communications supports up to 140 uplink messages a day, each of which can carry a payload of 12 octets at a data rate of up to 100 bits per second.

We use the BRKWS01 module from WISOL which allows messages to be sent over the Sigfox network. Since the amount of data that can be transmitted through LPWAN is small, and we have a lot of data to transmit, we choose different accuracy for them according to the importance of the data.

We optimized the data transmission, 9 data only uses 6 bytes to transmit, which saves bandwidth and reduces power consumption. The connected beehive sends data every 15 minutes.

• Ubidots

We implement the user interface through the ubidots platform.

We think beekeepers are the most concerned about honey production, so we put weight in the middle. To its left is the battery status and to its right is our own wind direction and speed widget written in HTML / CSS / JavaScript.

The third line concerns the information in the hive, the fourth line illustrates the information outside the hive. The temperature is to the left of these two lines, represented by the yellow lines. The humidity on the right is indicated by the blue lines.

In the event interface, we set up alerts based on the data conditions mentioned above (Data Analysis). The alert function in ubidots is customizable, users can also create alerts at will and according to their needs.

The method of creating an alert is very simple and efficient. All you have to do is define a trigger condition. For example, in this figure, when the temperature measured by the DS18B20 is less than 22 degrees, the alert will be sent.

You can also choose to send the alerts by email or sms.

The beekeeper logs in to his ubidots account and can view all the information of the beehive in real time.

Consumption calculation and optimization

Measuring

We use the device "Analog Discovery 2" and the software "WaveForm" to visualize the power consumption of the prototype.

After connecting as shown above, we can see the following waveform in “WaveForm”, average consumption is 6mA/h. This means that it can work for a week without charging the battery.

Optimization

• Software

We add a deepsleep mode.

• Hardware

We removed the two resistors R18 and R19 in order to turn off the led lights, removed the Solder-Bridge SB9 and SB14 in order to remove debugger.

Average consumption is 1mA/h after optimization. This means that it can work for a month without charging the battery.

PCB design

We completed the PCB design using kicad software with the help of the video tutorial of youtube blogger Eric Peronnin and the help of our teacher Viateur.

Since most of the components we use are not in the kicad library, we created a library of our own, named Stonks.lib, and completed the electrical diagrams of the components (for example: Sigfox module, acceleration sensor MMA8452, Nucleo- L432KC, the wind vane etc).

Similarly, when designing the layout diagram, some component libraries can be found on the Internet, such as LM386 and module Audio, but some components need to be created by ourselves, such as carte Nucleo. Here is the final layout:

After printing out our pcb, we replaced the breadboard with our PCB board and tested it.

Field tests

We conducted field tests at Apiary School De Plaisir, located on the west side of Paris. Here is a group photo of the team members with the connected beehive (from left to right are Fadi Shehadeh, Alexandra Deac, Yongtao Wei (the one in the phone), Amélie Kirady and Ismail Bennis.

Here is the box contained with PCB, antenna and battery:

Overview of the device integrated into the hive:

On the delivery date of the project, we had an in-depth exchange with the beekeepers at Sorbonne University. We introduced our project to them and taught them how to use it. In the end, we delivered our project "Connected Beehives" to them. This is a group photo of our team (from right to left: Alexandra Deac, Amélie Kirady, Yongtao Wei, Fadi Shehadeh and Ismail Bennis), beekeeper Jacky Boisseau (first from left) and our professor Yann Douze (second from left).