About Buffer On Wireless Sensor Network

 

Background

I recently had a request from a customer about whether WSN nodes could save data if a gateway failed. I was aware of the flash available on board and got to work on a possible solution.  This is a solution that I came up with (by no means the only way).

I would emphasis a couple of caveats before we start:

1. If you read the WSN node manuals the official advice is that the flash on board not be used to buffer data.  This is because every time you write to the flash it requires an erase and you only have a finite number of erases. With this in mind:
   1. I have designed this to only log when the network is lost.
   2. I have added the ability to check the current levels.
   3. I would only use this when you really need it, you will limit the life of your nodes but obviously this is a calcuation you need to make.  Additionally you could alter the firmware to change the rate at which you log to extend the life.
2. This does require the WSN module and programmable nodes as it involves you working on custom firmware for the nodes.
3. The attached Code is provided As Is.  It has not been tested or validated as a product, for use in a deployed application or system, or for use in hazardous environments.  You assume all risks for use of the Code and use of the Code is subject to the Sample Code License Terms which can be found at:http://ni.com/samplecodelicense.

With that out of the way onto the engineering!

Attached Code

There are three parts to the attached code.  There is a lot to this so the majority of the information is in the attached documentation.

1. WSN File Buffer Library: A library centered around an FGV to perform the buffering on the WSN node.
2. Example Firmware: An example WSN application written for the 3212 that implements the buffering and an example command set.
3. Host API: A LabVIEW class which talks to the example firmware to extract the relevant information.

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