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.
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.
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.
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.
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)?
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.
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?
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 [Dropbox - Error - Simplify your life]
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.
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:
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.
I have also a Seeduino Stalker version with a GPRSbee, this sends the data via GSM/GPRS to a PHP script. Data visualization is done by Dygraphs http://dygraphs.com/ There is alos a GPRSbee lib for MQTT so switching from HTTP to MQTT should be possible easily (not tested yet).
We have also a Berlin (Germany) based group that develops a much more elaborated backend for bee monitoring purpose under the project name hiveeyes
It is based on BERadio, Kotori and Grafana mainly.
HI Clemens. Will you be making you prototypes available to replicate? - I am trying a similar project. Just wanting to be able to able to send weight via gsm and have it plotted on a graph. I will probably have 12 scales in different regions in NZ.
Thanks!
