Illustrated

Grafana [7] visualizes the acquired data. The software supports numerous data sources, including InfluxDB databases. Because the official Raspbian repositories contain a relatively old Grafana version, we used a current package from GitHub [8].

The Grafana service also needs to be configured to launch automatically after boot with systemctl enable; the

systemctl start grafana-server

command calls the service, which users can reach from web interface port 3000 (username and password are admin). First, we used Add data source to add the telegraf database; then, we set up the dashboard to visualize the metrics (Figure 1).

Figure 1: The sensor measures temperatures between 8°C and 9°C (ca. 46°F and 48°F) at the upper edge of the lower hive frame shortly after 10am, when the RPi2B was hung in the hive.

We moved the RPi2B, at first provisionally protected with plastic bags and tape, into the beehive, which is located next to the house wall and can therefore use the existing wireless network (Figure 2).

Figure 2: The RPi2B is still in a temporary housing. A waterproof housing and a solar module for wireless power are on the shopping list.

To make room for the RPi2B and sensor, we took one slat out of the top floor of the two-frame hive. The DHT11 currently measures the temperature at the upper edge of the lower frame. At an outside temperature of 1°C (ca. 34°F), the average Easter weekend temperature was 8°C.

Close to the Bees

The temperatures are higher where the queen lives and where the bees breed (about 35°C, or 95°F). Other beekeepers have three or four sensors in the hives and measure the temperature at the entrance hole, under the lid, and in the lowest frame. You can check out the sensor results of the Hiveeyes project online [9].

With the information from a SunFounder tutorial [10], we experimented with a DS18B20 temperature sensor and a speaker module. To communicate through the GPIO extension board, we installed the Wiring Pi library [11], which provides the gpio tool (Figure 3).

Figure 3: The GPIO layouts.

The idea was to create a measuring device that emits an audible signal when a certain temperature is exceeded. Such a device could be interesting for transporting colonies of bees. If longer distances are planned, a transport grid on top of the hive ensures a sufficient air supply. For shorter distances, however, many beekeepers simply secure the hive with a strap.

When it gets too warm, the bees start flapping their wings to cool down, and when the hive is closed, everything heats up even more – the insects can produce such high temperatures that the combs and honey melt and the bees perish. A signal tone warns the beekeeper during transport and prevents the colonies from buzzing themselves to death while cooling the beehive.

Do Not Miscalculate!

A hive scale is planned for the summer to monitor the weight of the beehives. The beekeepers association in Nettetal, Germany, implemented such a project with an Arduino [12]; the data is presented by the Hiveeyes project. A scale is not only interesting in the summer to observe honey production, it can also be used in winter to better assess whether sufficient food is available. If it remains very cold for a long time, the bees will need more food – you can then see in time whether or not nutrition is becoming scarce.