Here is my simple weight monitor.
This is a bathroom scale I got from a garage sale for $ .50 I opened it up and attached 4 wire phone cable to the load cell inside.
(http://bombshellbees.weebly.com/uploads/2/6/7/3/26736847/3910914_orig.jpg)
I ran the phone line down into my basement where it hooks into a ina125 instrumentation amplifier
(http://bombshellbees.weebly.com/uploads/2/6/7/3/26736847/8031897_orig.jpg)
The amplifier is then hooked into an Arduino which is running a program which calibrates the load cell takes a reading and records that reading every five minutes. I think I want to change the program to take a reading every hour. Charting so many points in excel takes a toll on my computer. The next thing will be to add wifi capability. I need the bee experts to chime in on what types of sensors would be best to hook up in addition to the scale. I plan to do a step by step guide for people that want to build one. Using Arduino you could also use cellphone or bluetooth for a connection. This unit currently saves the data to an SD card in the form of a text document.
(http://bombshellbees.weebly.com/uploads/2/6/7/3/26736847/8064128_orig.jpg)
Ever once an hour might be more data then needed to be useful. You might want to put the data from every 6 hours or 12 hours into a file and see which is most useful. Keep us up to date with your progress. -Mike