# Measuring the weight of a beehive

first imagine an upturned box that is big enough for your beehive to sit on. (say about 8 inches tall).

Now sitting on top of this box is a platform that overhangs the box by quite a reasonable extent (maybe a couple of feet).

This platform is then attached to the edge of the box by means of hinges. So if you were to stand on the platform and walk past that pivot point, it would tip.

Underneath the platform (on the far side to the hinges) is a microswitch that will detect when the platform is tipped.

You can now place your beehive on the platform over the box.

In the meantime, underneath that overhang is a very heavy weight. This heavy weight is suspended beneath the overhang on a runner. It can also be moved towards or away from the pivot point by means of a lead screw.

So all the arduino needs to do when it takes a measurement is draw the weight all the way in unitl it finds the end stop. Then slowly move the weight (by turning the lead screw) until it detects that the microswitch has been tripped.

From calibrations carried out before you deploy this gizmo you can then use a lookup table to see what weight that distance implys.

Naturally, you could have a saftey catch to prevent the platform rising any more than a couple of millimetres, so there's no danger of the beehive ever being tossed off.

If you like I could probably knock up a diagram in paint to explain better.

OK I decided to go ahead and draw the thing.

So the idea is. When a measurement needs to be made, the arduino will spin the motor up to make sure the counterweight is all the way in to it's home position.

It will then slowly move the counterweight away from the pivot until it detects that the platform has lifted on the far side. The distance it has moved the weight will be able to be used to assess the weight of the hive on top.

Oh I've just noticed that I didn't label the hinge (it's that blue blob near the counter weight. It's this hinge that allows the platform to tip when the counterweight is moved away from it.

Microswitches do tend to wear out, I have a collection of dead computer mice to attest the fact.

You might take a look at light interrupt though a led as light source has a finite life even only lit during measure. You might take a look at piezo disks as touch sensors, the sensitivity can be varied and the life is very long. You might look into some form of capacitance sensor also with a very long lifetime and can be made really cheap.

I had mentioned putting the hive on a counter balance just to reduce the load cell required, months ago. It's nice to see some physics used to engineer the parts needs down but running a motor will up power requirements.

Microswitches do tend to wear out

a magnet and a reed switch would do the job nicely.

As an alternative to the weight on a motor, you could have a tank that fills with water sitting on top of the platform. Then all you need to do to trip it is open a valve (that allows water from a separate reservoir) to add more water. When it starts to tip, the level guage is read. A separate valve could also be opened to allow water to drain back out.

The reservoir could collect rain water to keep it topped up.

KenF:

Microswitches do tend to wear out

a magnet and a reed switch would do the job nicely.

A reed switch will trip over a range of distance, much less tunable than capacitance or piezo touch. Capacitance is still not as good as physical touch or light interrupt can be. Piezo can tell how hard is the touch.

I am a fan of piezo disks after experimenting with them. There are cheap ones that work just fine as buttons. They don't need debounce, give pressure data and can take a good bang. I got 100 for just over \$10. Downside is they need other components to work as I did. I used diodes, transistors and resistors.

Hi Lars, I'm doing a similar project.

I bought a simple bathroom scale. Removed the 4 sensors en mounted them on a board of wheaterproof pliwood. On top of that is my beehive. This 4 sensors to the INA125 and to the Arduino.

Also I installes a humidity and temperature sensor in the beehive. Future expansion is a counter to measure the activity at the gate of the beehive.

From the arduino a WiFi module to my home network.

http://www.ebay.com/itm/171495443192?_trksid=p2060778.m2749.l2649&ssPageName=STRK%3AMEBIDX%3AIT

I have to do this 20 times. Me and my friend we have 2 times 10 beehives.

The final goal is to publish the weight results into HTML to be viewed in graphs everywhere I am.

So how far are you in the meantime?

Regards, Wim

Hi Wim / Paysan,

I work in electronic and have also beekeeping as hobby. This project is very interesting: great job realized. I have just a few questions:

Have you thought about using pessure sensor as MPX5100 to measure hive weight: using simple smooth hydraulically linked containers placed on 4 corners's hive? Preesure is then, function of weight.

About battery, why don't you use a lithium battery size D: it's what is used in industry for GPRS system, which is adapted to Temperature, long life duty and high current need for GPS?

Could you please share your realisation (schematics, ref for OTS parts and SW code)?

Thanks and regards

Alain

Thanks for all the diffrent suggestions. But i still think, why get it so complicated when it can be done simple. hydraulically, mecanically etc.

I use a single beam Loadcell (8 \$ each (when bying 10 pcs)) and a cheap ( <5\$ ) HX711 Dual-Channel Weighing Sensor Module.

And it Works.

Hi i working on similar project,i made scale for my beehive.I use arduino uno r3,gprs gsm shield sim 900,7.4V 1000mah lipo batery,DS1302 Real Time Clock,HX711 24 Precision AD Module Pressure Sensor Module Weighting Sensor, DHT-11 Digital Temperature and Humidity Sensor,and four cels from home body scale. two times in day i recive sms with weight,humidity and temperature.i nead resolve problem with batery,does someone know how i can recive in sms how much i have power in batery,or alarm whan i hawe low power? thank you for any help? if you want i can post picture of my prototipe!

Hi, KenF, I love it, a work of art, you could sit and watch it weight all day.

It would be a great educational tool to teach these hi-teched kids these days, that a controller and programiing and some HeathRobinson (not sure of US equivalent, I know Art Goldberg, new knew the Mythbusters would eventually help my edjamacation) can do.

Rather than just poke a iphone at it and get google to come up with the answer.

Tom.... :)

TomGeorge: Hi, KenF, I love it, a work of art, you could sit and watch it weight all day.

Thanks :)

Hi bboris Try to look at this genius piece of hardware: https://www.tindie.com/products/Dead_Bug_Prototypes/extreme-low-power-data-logging-shield-for-arduino/ It is based on the RTC DS1337 with a smart power-down function (or sleep-function)

I am on a research team doing exactly that: We have put several bee hives on load cells to log weight at intervals of 10 min, or even 2 min, for several months. The load cells are expensive (little creep and 20 g precision) and are not an option for you.

My main message is: You should not worry about creep! You are interested in the daily weight gain, so make sure to measure weight at least every midnight. Subtract subsequent midnight readings and you'll achieve accurate measurements of daily weight gain, despite any creep (the creep during 24h is neglible). Add all the daily gains and you have the total amount of honey produced.

Bonus info: If you pile you hives high, wind will catch them and disturb your readings. Second to second weight readings could change by 1 kg! Therefore, to obtain one good reading, obtain several readings (say, 30 readings at 30s interval) and compute one reading as the average of that. Maybe calculate standard deviation also to get a measure how precise your average is.

Beekeepers all over the world are on to this, mesuring bee hive weight, temperature, rel. humidity, CO2, sound and vibrations! What this avalanche of data all means, is still an open question, except daily weight gain (or loss), that's easy to interpret and put to use, right?

Good luck, Niels, Aarhus University, Denmark.

Hi All,

Could you please share links to your projects, as I am very interesting to monitor my beehives during this winter ?

Best regards

Alain

Hi Alain, In winter, if the bees go into hibernation and form a winter cluster, you will find that each hive looses weight at a constant rate. The rate likely depends on the size of the bee colony; it should be roughly proportional to the number of bees. Or, blame my intuition, maybe proportional to the cubic root of the number of bees, since they form a sphere?

A flat-lining behive (rate of weight loss = 0) means the colony is dead.

Snow will interfere with your readings as in this Danish study, where readings with snow cover were left out [https://www.dropbox.com/s/kmwqukorycwz8ca/overvintring.pdf?dl=0]

The figure shows weight drop in two consecutive winters, together with the loss rate (g/day) equal to the slope of each line. There is one line for each hive in both winters.

• Niels.

In this posting Lars showed a photo with pieces of alloy to mount a load cell.

I constructed a low cost variant of a bee scale. The load cell is mounted between two alloy profiles and distance plates. The holes must be drilled very accurate so I use a CNC for this:

You can find more photos under: https://www.facebook.com/media/set/...

Hi Lars, after finishing my prototype I ask myself why your prototype http://bildr.no/view/dUJJYWRC or http://forum.arduino.cc/index.php?topic=113534.msg1473176#msg1473176 looks like it looks. :-) You do not use a whole L-profile at the bottom. You have some gaps right and left on the vertical flank. Is this to mount it on a subbase? How is the load cell mounted on the lower L-profile?

Do you mount the scale on the front or back of the hive? Or left/right? Front vs. back has the disadvantage that weight is not divided equally in the hive. With honey in the back you have always higher load on the back side. If you put it right/left I think this is not so a problem. But mounting on a shorter side is more easy and more practically.

Digging this guy up from the dead.

Where is everyone on this project?

Gilligan: Where is everyone on this project?

I have different prototypes running:

• Weight Platform Prototype I with Film Coated Plywood
• Weight Platform Prototype II low cost module, weights only one side of the hive
• Shields for Seeeduino Stalker (3.3 V) or Arduino Pro (3.3 V without RTC) and Yun / Uno (5 V)
• a prototype with an ESP8266 on a breadboard
• and also a prototype version with an Arduion Pro Mini and GSM

With the Seeduino Stalker and Arduino Pro as node I can use radio (RFM69) for data transfer, gateway is an Arduino Yun. I used this lib for RFM69: https://github.com/LowPowerLab/RFM69