Based on my work from last winter and other awesome work that the community has done. Some if it even documented right here on hackaday.io, I decided to add weight measurement to my setup. For now due to cost it only encompasses one hive but I already have plans to add more!
The build is pretty straight forwards, the first step is that I purchased this scale from Amazon:
Upon receiving the scale, I started running some experiments and naturally taking it apart, here is an internal photo:
There's really not much to it, just some strain gauges and wires. What I liked about this one is that it had some very nice readout electronics that were external to the scale so I could simply cut the wire, add a connector and swap out my custom electronics with the "gold standard" any time that I wanted to. This proved to be very useful during calibration.
For the strain gage ADC, I selected HX711, this is a very popular device because it is easy to use and really just works!
Using nearly all of the same wireless hardware as I used for my Temp and Humidity project, I used the spare IO on the droplet to interface to the HX711.
Because the size constraints on this device were less and power consumption of HX711 is higher, I decided to power it from two AA batteries. You can also see the waterproof enclosure that I am using.
Luckily because this radio is outside of the hive, I can also now get full range WITHOUT the need to the AC extension cord and hub in the woods. Now the hub can sit comfortably indoors.
Here's some pictures of the installation of the scale into the hive:
In the end, you really cant even tell that it is there!
So here's the data:
What I find fascinating is that each day, you can see the volume of Bees who leave the hive to forage and then return in the evening. This is a very periodic pattern and you can even see the days which it rained (because they stay in the hive).
Also, the two discontinuities of weight in the chart are due to adding and removing an additional "Honey Super" to the hive stack.
We were really thrilled to see the awesome nectar flow in the month of July, things have sort of settled down in the last few weeks but I'm hopeful that there will be one more flow before the honey is harvested!