Sitch Mobile Sensor MkI

Here’s a quick rundown on the purpose and parts for this sensor:

Purpose: Untethered sensor, dials home via a WiFi connection. Bring your own cellular hotspot (though if you suspect rogue base stations…) or if your destination has open WiFi, there you go. The system will continue to run disconnected, so for information gathering purposes you can still gather on the road and the results should be forwarded to the collection point when you get within range of your configured SSID.

Sitch MkI Sitch MkI

Parts:

  • Pelican 1200 case (because sex appeal)
  • iFrogz 9000 mAh USB battery pack
  • NooElec NESDR Mini
  • Raspberry Pi 2 Model B
  • StarTech USB cable (left angle)
  • JBtech Jet Black Case for Pi
  • Samsung 32GB Pro micro-SD
  • Globalsat ND-105C Micro-USB GPS receiver (with adapter)
  • USB 802.11n WiFi adapter
  • USB extension cable (used to distance the SDR from the pi)
  • Log periodic antenna from Kent Electronics (http://www.wa5vjb.com/products1.html)

I cut the wire from the baby whip antenna that came with the NESDR and soldered it to the one I picked up from Kent Electronics. The antenna tucks away nicely under the foam and still gets good reception. The SDR generates enough heat on its own that you’ll never be able to get away with running it with the lid closed for very long, and be sure to leave enough clearance around the vented side of the pi case so your CPU can breathe.

The Pelican case is pretty much overkill unless you can find one second-hand. A shipping box with foam inside, cut to fit the equipment, would do well enough for most situations. This is the Cadillac version- great if you’re taking it out in the elements for whatever reason. I’ve run it for beyond six hours on that battery pack and there’s plenty of juice to go. I’ll do some testing at some point in the not-too-distant future and get some real metrics on battery life. Stay tuned.

With the exception of the antenna, everything you see here was acquired on amazon.com. Later this week I’ll try to put together some material on the barebones kit- the one that’s supposed to be at or under $100.