I am building two low bandwidth, long range, wireless nodes. I've already built one node, using my Arduino Decimila, and am building the second node now, using a Teensy 3.1. I've started working on the Arduino software, and have the initialization code ready to test now.

My wireless nodes are based around a 433 MHz long range (1 Km to 2 Km), low bandwidth radio link. My thought on this is that sensors generally don't really need to send a lot of data, and data requests won't require much data to be sent to the node. This project is really all about the wireless range.

I already have an application for it in my life - I recently lost a very sweet little puppy I will probably never see again. If she had one of my wireless sensor nodes, with a GPS unit attached to it, I might have been able to find and recover her.

My first node has a DHT22 temperature and humidity sensor, eight NeoPixel LEDs, four switches, and a small 8x8 matrix display attached to it. It's powered by a lithium battery pack. The arduino and battery pack are attached to a double wide shield expander. You can't see either of these in the picture, except for the external connections, because they are under the shield expander.

Now, I am working on the software routines to pack and send data between nodes. This is where I have a lot to learn. This is completely new territory for me to be working in. It's also very exciting! If I can get this to work, I will wire up the circuitry in a more permanent form, so I can get away from all the jumper wiring and make it more reliable. I will be able to do this myself now, thanks to these Perma-Proto boards from Adafruit.

Below is a picture of my first wireless sensor node. The small breadboard has the 433 MHz wireless transmitter and receiver, as well as the 8x8 matrix display and DHT22 temperature/humidity sensor. The larger breadboard has the eight NeoPixel LEDs and four switches. I haven't wired up the switches yet, because I don't have the resistors I need.

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This is a perfect application for the Teensy 3.1, and I am very excited about it!. It also has an application in my W.A.L.T.E.R. 2.0 project.