===== Packet Options for Remote Sensing =====

The problem is that in order to monitor BB from 4 miles away we currently rely on a telephone connection. This has been mostly adequate but does not provide real time casual monitoring of systems. A Radio Link will also allow a remote weather station to monitor environmental data, something that's not possible in the woods at Downing Place.

The options for adding a packet radio consist of the following:

==== TinyTrak 4 ====
This is a complete send and receive TNC. It's compact and low cost but would require a radio. It's not much different from the Hansen TNC except it's smaller.
 
  * Pro: compact, low power, low cost
  * Con: No radio
  * Implementation: An AVR hub would gather sensor data including a weather station and use a smart algorithm to send data to the radio. A separate low cost, low power radio would be required .
  * Cost: $57 kit form plus radio. Can probably use the Yaesu, although the Yaesu is targeted for use in the base.

==== Micro Trak 8000 AF ====
This is a one way packet transmission system. It's compact, medium cost and is self contained. The radio, which is frequency agile, is onboard. This can be repurposed into a vehicle position tracker once it's no longer used at BB.

  * Pro: ultra compact, low power, medium cost. Includes Radio
  * Con: Only sends one way. 
  * Implementation: Uses the AVR hub as before but a radio is not required.
  * Cost: $190 built and tested, ready to go. 

==== Hansen TNC ====
This is a klugy board but it probably works. It can be used in the interim to test a system. It still needs a radio to function.

  * Pro: Already have one. Low power, free. It's not compact and is probably not reliable. It would be bidirectional.
  * Con: Kludgy, needs a radio.
  * Implementation: For testing it may work well. For a radio I would use one of the RS handheld units.
  * Free.

**Conclusion:** I need to build the Walkure AVR hub to gather data on an RS485 network. I then need to build Nibelungen devices to communicate with the hub. The hub output will be to a packet system. There is no hurry to purchase a Radio System until the hub and clients are implemented. This needs to be ASAP to accommodate the winter of 2009/10.