A first snapshot of hive activity!

Now that the BeeDuino is up and running I’ve had an opportunity to grab some of the data to see what kind of stories we can tell. Here are temperature logs for a couple days:

beehive_weights_4_23

If you look at the steady temps on the “B” frame is is pretty clear that our newly-installed package is clustering off-center in the hive – the “B” frame is the 3rd frame from the right-side of the hive. The temperatures for that frame stay consistently at ~95F day/night.

The other interesting story is how the other frames stay consistently warmer than the outside temperature (yellow line) – the “A” frame is in the center of the hive, so closer to the “B” frame, and so warmer than the “C” frame that is located farthest away from the cluster.

I’ve also pulled in some weight data. The scale is at this point undetermined – I haven’t correlated the readings in mV to actual weight, however it is still interesting from a relative measurement standpoint

beehive_weights_4_23

Basically every day the hive weight goes up. This makes a little sense when you think about a couple factors:

  1. There is a 2-gallon sugarwater feeder in the top of the hive. The bees are still consistently feeding on both the feeder, and during the day there is lots of foraging going on.
  2. If you look back at the temperature/humidity plot, there is a significantly higher humidity in the hive than outside.

So, looking at these factors, we can expect a continuous DECREASE in hive weight if the bees are continuously feeding off sugarwater – the net weight decreases as the bees evaporate water into humidity/the atmosphere. OK, so that makes sense and probably explains why the hive loses weight throughout the evening/night hours.

So what is goin on from ~8AM until sundown? Every day the weight goes back up! I would guess this means that the large number of bees leaving the hive and foraging are bringing nectar/pollen back to the hive, resulting in a daytime increase of mass.

Once the bees are sufficiently established and stop feeding off the sugarwater I’m hoping to see some daily ripple, with an overall increasing trend.

Yay data!!!

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5 thoughts on “A first snapshot of hive activity!

  1. This is awesome work! My university recently got a couple of hives, and I am interested in building this sort of system to collect and display data to the students. I’m wondering if you got the tweeting to work, and how exactly you are measuring the weight (in mV I see).

    • I see now that you are measuring the weight with a Flexiforce thingamajig. Do you just leave it under the corner of the hive all the time, and get a cnstant stream of data?

      • Hi Joseph,
        I do just have the sensor under one corner – i’m just sampling the data once every 5 minutes. Deamiter points out below the temperature sensitivity – I hadn’t taken a close enough look at the datasheet, there is a pretty significant temperature impact on the data.

  2. Be careful that the flexiforce sensor varies by up to 0.2% of the full scale per degree temperature change!

    http://www.tekscan.com/flexible-force-sensors#specifications

    That means that it varies 0.2 pounds per degree or 2 pounds per 10 degrees (a very normal daily temp swing)! Unfortunately, when you look at short-term data like this, the sensor is acting more as a thermometer than a force sensor, although over the entire year, it can get you reasonably accurate daily data (plus or minus 5 pounds or so).

    I put together a system with an Arduino that uses a postal scale with load cells, and while I wouldn’t recommend repurposing the postal scale, I’m working on designing my own hive scales using a decent load cell. Even then, you’ll need to compensate for temperature, but the error due to temperature is down around 0.002% per degree — 100 times better than the flexiforce sensor.

    I don’t plan to have this finished before next year if I have to do all the work myself (kids and work limit my free time) but I’d be happy to show you how I think it could be done if you want.

    I’m recording my progress at http://hackerbee.com and in my latest post you can see my weight data before and after compensation (approximately 0.007% variation in weight reading per degree celsius).

    • Thank you for the heads-up! I didn’t dig into the datasheet properly, that is a pretty big temperature sensitivity! I had the flexiforce sensor laying around, so I stuck it into the hive, but your definitely spot-on – this won’t be good for short-term data.

      I like your usage of XBee radios for comms – I’ve been struggling with the WiFi shield dropping off my local network, I mat have to reporpose a couple XBees I have for a DIYDrones project to do the bee data. Have you had any reliability problems with the radio link, other than the enclosure/case for your scale? The WiFi shield doesn’t seem to want to run for more than 3-4 days without a restart…

      I would like to hear more about the scale – I might be able to assist some, depending on my work travel schedule!

      Cheers, JJ

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