Thanks a lot for the reply Clemens, what is the other benefit of the Seeduino over Arduino Uno for example apart from being 'plug and play'?
34.5 mA.(see "Baseline-Arduino Uno" http://www.gammon.com.au/forum/?id=11497
) vs. 600 uA (http://www.seeedstudio.com/forum/viewtopic.php?f=16&t=3911
) plus you have RTC, SD card, solar charger circuit, bee socket
Arduino Uno with Power Saving library by Rocket Scream (found this at comoyo.github m2m adventures measuring temperature of water and air, this seems to be in line with my project except I will record weight) Nick Gammon appears to offer other techniques to save power but it is too complex for me, so unless I need greater power reductions I won't go down that path. Hopefully a solar trickle charged battery that powers the Arduino, suggestions?
LowPower lib makes more or less the same as described in Nick Gammon article. Consider to use Narcoleptic lib if you will use time information (e.g. without RTC) it recalculates millis for more accuracy but use the right version, see http://forum.arduino.cc/index.php?topic=121096.msg1768493#msg1768493
. About the charging approach have a look at the Seeeduino Stalker spec http://www.seeedstudio.com/wiki/Seeeduino_Stalker_v2.3
be aware that it is the "Stalker" not an other Arduino clone from Seeeduino.
The most load cells are temperature compensated, I don't know how problematic creep is. For the accuracy we need to measure hive weight is seems to be not problematic. But please read the whole thread there are useful information and a hint to use not 3 wire load cells.
I had intended to use one of the following MCP3551, ADS1231 (I think you used this Clemens) or INA125P - can you help tell me the difference between these, if any?! So far I am leaning towards 1 of the MCP or INA only because I have seen others use it so should be able to wire it up OK. Any advice here?
Be aware that these are different ICs the INA is an OpAmp while the ADS and the HX711 has a gain amplifier but also a ADC with a higher resolution than the Arduino's internal ADC (10 vs. 24 bit). But read the post from Lars in this thread http://forum.arduino.cc/index.php?topic=113534.msg1173511#msg1173511
about using oversampling to reach 12 bit in case you will an OpAmp only.
Also (just making the most of the time difference) - instead of using watchdog which only allows an 8s sleep, would it be better using a real time clock to sleep it for the 1 hour? - assume this would be more energy efficient.
The 8 vs. 60 x 60 sec seems not to be that problem if you have the right board, see http://lowpowerlab.com/blog/2012/12/24/moteino-coin-cell-battery-tests/
how about 3 years with a 2 x AAA pack? ;-)