Measuring the weight of a beehive

Using Arduino Project Guidance
9

LEGO-lars:
Hi.
A little update.
After a bit research, a load cell seems like the best solution. I just have to find one cheap enough :wink:

My plan so far is to in each beefarm have one control box(master), and several scales(slave) that will communicate with each other using wireless transcivers.

The control box will be powered by a lead acid battery, and contain an microcontroller, a GSM module, a RTC, a wireless transceiver, sensors for measurment of temperature, humidity and rainfall and maybe a load cell with a fixed load for using as a referance.

For the hive scales I was tinking of using a single load cell made for platform scales. For the op-amp I was thinking about the ina125 http://www.ti.com/lit/ds/symlink/ina125.pdf since it got an onboard voltage referance and a sleep mode.
For communication I have looked at various NRF24L01+ transceiver module since it is cheap and have a low power consumption.

To power the scale I was thinking of using a small solar panel to charge up a supercapasitor. when the supercapasitor is charged up, the atmega will wake up from sleep, measure the weight of the hive, transmit it to the master, and then go back to sleep. I only need 5 or 6 samples during the day, so the atmega and radio, will be in sleep mode for 99% of the time.

Does this sounds manageable solution? I do not have much experience with op-amps, and I have never used wireless transceivers. So if someone has any opinions regarding to these, I would be very grateful

Well it sounds like you have a good grip on what is required to perform what you have defined needing to be done. As far as manageable, that would depend on your experience and ability to keep plugging away at it. I would suggest you approach the project in steps. I would recommend you first work on getting the wireless network working between the master and the number of slaves you will be using. Wireless (software & hardware) can be very taxing to get going from basic components, it's never as easy as it first sounds. Once that is mastered and working well then you can make the higher cost investment in the load cells and support components and the mechanical packaging, etc.

Good luck
Lefty