Build a datalogger for your wireless sensor network

We needed a datalogger that provided a timestamp, and that would last 2 weeks in the woods. Using a laptop would require a generator or humongous battery. This Instructable shows how to make a datalogger from an Arduino and datalogger shield connected to a TelosB wireless sensor board and a battery that is large, but not wheelbarrow large. Your data goes onto a SD memory card on the datalogger for pickup later (whenever you have to change the batteries on all the wireless radios in your network, for example). The main challenge is getting the serial signal out of the TelosB before it gets translated into USB. We could probably have reprogrammed the TelosB to output the serial on another pin, but why program when you can solder? 

Step 1: Get the items

Here is the shopping list. It is about $180 for the electronics, $200 for the case and battery. (US) It is cheaper than a netbook and you would have to buy the case, battery and TelosB anyway.

Get a Crossbow TelosB wireless sensor node--or a Moteiv Tmote Sky. MEMSIC now (July 2010) distributes the open-source Crossbow TelosB boards which is good, Crossbow and Moteiv no longer do.

Get a Datalogger Shield (Adafruit) - in the second picture below it's attached to an Arduino but you're just getting the shield. Buy a 1-2 GB SD-card or a micro-SD card with adapter.
http://www.adafruit.com/index.php?main_page=product_info&cPath=17_21&products_id=243

Get an Arduino Mega
http://www.adafruit.com/index.php?main_page=product_info&cPath=17&products_id=191

Get a waterproof case: we used Pelican 1450 and got a small can of silica desiccant to put inside.

Get a large 6-12 Volt battery. A rechargeable sealed lead acid or deep-cycle marine battery is good. Estimate lifetime: the datalogger uses at most 100 mA at 6V. A 50 Ah 6V battery is good but a 50Ah 6V battery is 26 pounds.

http://www.batterymart.com/p-optima-6v-red-top-battery.html  
part number OPT-850/6, can be used in any orientation and charged with a 6V "Battery Tender" 

This battery should last 500 hours (nearly 3 weeks), more if you carefully write your program to turn off all status LEDs and write to the SD card only occasionally. A 12V battery could also be used with the Arduino Mega. What really happens when it starts to go out is your datalogger turns off and on a lot, probably cycling with the outdoor temperature. Hopefully you collected lots of data before then.

We used hose clamps to connect a power jack to the two large battery terminals. The 2.1 mm power jack for the Arduino Mega came from a wall adapter. Center is positive and outside is negative.

You might also add an external antenna on the TelosB for better reception. Compatible parts available at DigiKey are
SMA connector ACX1233-ND, 30cm cable 602-1066-ND, and antenna A24-HASM-450-ND. While at DigiKey pick up 30 gauge wire, sockets, jumper wires, and a power cord with a 2.1mm jack or a cheap AC adapter for harvesting the power jack.

Comments

[derte84]

This is something I was thinking for a long time. Do you think it's possible to use arduino + shields t do a wsn? (I mean without sky/telosb nodes)

[derte84]

Oreilly give me the answer: YES. http://oreilly.com/catalog/9780596807740

[rrkelley1225]

I see no reason you can't. The form factor is a little large for wens though.

[manicmonday]

What does the word Arduino mean? I am not entirely electronically stupid, but since this word is being bounced back and forth on this site and I don't know what it means, then I feel like I'm stupid :( Thanks

[gooseflight]

http://lmgtfy.com/?q=arduino

[shinyshadow]

Arduino is an open-source electronics prototyping platform based on flexible, easy-to-use hardware and software. It's intended for artists, designers, hobbyists, and anyone interested in creating interactive objects or environments.

[rzprk]

an easily programmable atmel-based microcontroller board that features 6 adc & digital i/o pins. see http://arduino.cc/

[BlueFusion]

Can I recommend something that could drastically improve your battery life... Instead of having a radio like this which uses power very inefficiently by being on all the time, switch the radio on (with the arduino) only when you need to use it - or use a different, low-power radio that can do this automatically. Another great power-saver is to have the arduino power-down (sleep mode) when not using it. This drops its current draw from many milliamps down to a few microamps. Using both these techniques, it's quite simple to make a wireless radio datalogger that can last for weeks if not months with simple AA batteries. :)