[MakingThingsWork] wanted an accurate way to keep track of the weight of his beehive, so he decided to build himself a data logging electronic scale. First he ripped the strain gauges from an old electronic scale which he then fitted to his home made beehive base. He then went about designing and building the control board which is based about the Attiny 85 (if you hadn’t guessed by the banner). An instrumentation amplifier was used to amplify the signal from the strain gauge, which is then read by the ADC on the Attiny. It looks like he had some trouble getting consistent results from the scale, so to eliminate the error caused by temperature variations he set up a fixed voltage divider for reference. With this setup the scale can produce results at +/- 0.5lb accuracy, sounds just fine for a system that cost less than $50. The V-usb project software has been used to connect the scale to his PC which he uses to collect and graph the data. All in all a very neat project and by the looks of it, some very productive bees.
thanks for this post, really!
I’ve been planning on making this bee-hive-scale for a friend of mine and this will help speed up the process!
Won’t prolonged use badly decalibrate the electronic scale?
I’m the maker of this hack.
I expected the scale to lose accuracy or change the reading over time, but i haven’t seen any evidence of that so far. I tested it for about a month with about 90lb on it and it didn’t waver at all. It’s been going for about 9 months now under the hive, and so far everything seems OK.
I do put a weight on it periodically to verify it still reads true, and recalibrate if necessary. Hasn’t needed much.
NEAT combo of a tech hack and the survival of our species. Strain Gauges are often written off as too complex for Hackers. And major Karma points for having a hive!
My first thought seeing this was how trivial it would be to Tweet enable the code or it’s output files.
The second thought-those Bees are workers in Spaceship Earth’s Life Support System.
I used to service scales that used single block gauges. The calibration procedure involved “building” a weight stack in increments, and moving the individual weights/whole stack around the platform. IIRC- from nearly a dozen years ago-the sequence was determined either by scale maker or a state weights&measures dictate.
Hmn. Some mechanism for lowering one or more known weights onto the assembly being weighed- then raising them- repeat to validate result linearity?
I’ve been beekeeping since I can remember, my grandpa, dad, and a partner in the business has been getting more and more hive’s every summer. They got about 10 semi loads this year and I helped with the pull, super, and a bit of the extracting process. I left North Dakota to go back to Minnesota once we were ready to ship them back to California… But back on subject, I’ve been talking about making a hive that we would winterize and make an observation part for a webcam and a thermometer to stream to the internet year round. Never thought about incorporating a scale. Nice hack, it defiantly gave me a new idea if my family builds the observation box (why buy when they can build one for free). But I will have to take it one step at a time… I’ve also thought about having out here in Minneapolis but it’s $100 for registration, 80% of people in 200ft from property must write and sign a letter saying it’s ok, fencing requirements, & blah blah blah. It will just be easier to set it up in ND since I still rent and I’m a poor college kid :)
any worry about the bees seeing the wire going in that grate and thinking.. “hey, a new hive!”?
@David, when my bees swarm, I am just ready with my bee vacuum and a new box to put them in. Sometimes they end up somewhere I don’t want them but generally, they do not move in to a new place that close to the old hive. Of my 35 hives, I caught 6 swarms this past summer, and had several others that simply got away. One of them was found to have moved into the side of an old shed in my field but it was quite a distance from the original hive.
Drat. The title had me thinking someone hacked a tiny scale at the hive entrance to weigh individual bees as they entered to see who brought back more pollen and nectar.
The average worker’s lifespan depends on so many variables that it might be nonsensical to even try. But that pursuit of such things is a “because we can” sentiment. I think that the resolution needed would be a non-trivial expense if you paid commercial prices. If you hack some common scales?
DealExtreme and a few similar vendors have scales that approach what’s needed for single Bee measurement. A few moments search gave values centering about 40 milligrams pollen carrying ability.
Apiary Science
We do what we must, because we can.
For anyone else building something with digital scales, the INA125 is an excellent instrumentation amplifier that has a built in precision voltage reference – which helps with reducing the temperature drift mentioned in the blurb.
Just like others here I was working on something like this. However, while I still have strain gauges cluttering my desk, you got it done. great job! You have motivated me.
Wow this is great work, thanks!. Im sure it could be commercialized. I have bees also, and being able to weigh my hives with this sort of frequency/accuracy would be awesome! Except they are too far from the house to run a cable and I dont have a laptop. Might be an idea to do some sort of wireless communication with my desktop…Waiting for my first arduino to arrive so I can finally get fiddling, will bookmark your site for when Im a bit more confident with MCUs etc…
It would be pretty simple to assemble a digital scale shield, and combine that with an XBee for wireless communications, to be sure. A solar panel and battery would make it completely independent.
Or maybe I could just wire an on/off switch to some scales, weatherproof them and leave them out there and do manual readings lol
just wonder…
does the weather condition not falsify your results… bees aren’t super active during a heavy rain… just all the wood is soaking wet and full of water ;)
Isn’t .5lbs a pretty big deal? I understand the feasibility of reducing the accuracy, but that number seems pretty high for this kind of situation. .1lbs seems like a more reasonable tolerance.
checking back in..
@torwag: I’m measuring weight, so i don’t see it as falsifying. The hive gains 1-5 lb during rain, and it evaporates over the next few days.
@malikaii: indeed, this is rev. 1. Hopefully future versions will have much better accuracy etc.
@matt: non-hacked (cheap) scales will re-zero (tare) to whatever weight is on them when they boot. This is why it takes them a few seconds to turn on, and is how they compensate for temperature, etc.
@nick: i am experimenting with some of those ‘solar cell phone chargers’ which have a built in solar panel, battery and usb (5v) output. Why build a minty boost when you can get the full package for like $5 on ebay. Add some RF12b and that’s a battery+solar+wireless job for ~$10