Bee Stock Hive Logger (weight, temperature, humidity, light) via 2G/3G using GSM Sim900

Inspired by the demand of a working collegue of mine, who has a few bee populations, I developed a small Arduino based device which:

– measures weight, temperatures (in bee stock, outside, in electronics box), humidity, light intensity, battery voltage
– does temperature compensation for weight result
– transfers results via 2G/3G network to a backend server
– goes into a deep sleep to save energy (because we have to use a battery, because of offsite installation on field/ in forrest)

There are a few comparable projects out there in the hackerspace, which did not fit our requirements, but were used as inspiration regarding different aspects:

A PCB was created to connect all the components in a clean way (the breadboard was horrible in the end):
– Arduino Pro Mini (I removed the power led to safe power)
– Pololu 5V, 500mA Step-Down Voltage Regulator D24V5F5 (to power the Arduino directly and efficient with 5V)
– Pololu 5V, 2.5A Step-Down Voltage Regulator D24V22F5 (to power all sensors and the Sim900 and shut them down via the POWER-EN pin of the regulator)
– Sim900 GSM module (connected via pin header)
– 2x HX711 breakout boards as we use two weight cells (via pin header)
– DS18B20 temperature sensor on pcb (for temperature directly at electronics; for temperature compensation)
– DS18B20 IP67 with cable (for temperature inside stock)
– DHT21/DHT22 with cable (for outside temperature/humidity; for temperature compensation)
– voltage divider (for battery voltage monitoring)
-Luxmeter BH1750FVI via I2C

The working procedure will be:
– wakeup from sleep, powering up devices, waiting 20sec for let them come up
– communicate sim pin to Sim900 module to let it search for cellular network and login
– performing 5 measurements with a delay of about 10 secs, calculation the median of each value
– dial into internet with Sim900, transferring data to Thingspeak via http-URL-call
– shutting down devices, bring Arduino into deep sleep for 1h

The Sim900 module needs to be prepared (correct band selection, fixed baudrate 4800) as described here:

The first version of the PCB is currently in production at OSH Park and looking like this:


I will post pictures of the assembly after building it up. When confirmed to work properly, I will publish the schematic as well the Arduino code here.


Leave a Reply

Fill in your details below or click an icon to log in: Logo

You are commenting using your account. Log Out /  Change )

Google+ photo

You are commenting using your Google+ account. Log Out /  Change )

Twitter picture

You are commenting using your Twitter account. Log Out /  Change )

Facebook photo

You are commenting using your Facebook account. Log Out /  Change )


Connecting to %s