One typical use of the Node, AKA Low Power Sensor and Transmitter, is to connect it to a sensor. Futurlec offer a nice range of sensors which work very well with the Node. The total build time is probably around 20 minutes.
Connecting an air quality control sensor was quick work, but we immediately wasted time seeing who could get the highest reading, and therefore had the worst carbon footprint, which added another 20 minutes onto the build time.
This tutorial will focus on the LPG sensor and Air Quality Control Sensor, but they are all much the same. A quick disclaimer: This tutorial is for fun only. If you are using it for any serious monitoring, you’re nuts. Consult the appropriate documentation.
Here’s what you’ll need:
- Arduino with wicked Receiver, connected to a computer
- A Node
- A 20KΩ resistor, or thereabouts
- The sensor of your choice, and optionally, a sensor socket
- Some wire, and if you want, heat shrink tubing
First, take a look at the circuit diagram in the datasheet:
It calls for what seems to be a variable resistor of about 20KΩ, and connections to 5v and Ground.
We didn’t have a variable resistor, so we just used a regular 21K resistor, and it worked fine. The datasheet has a table with the response curves, but you don’t need to worry about that just yet.
The picture on the right shows this on a sensor socket – It’s not the best picture (sorry) – click to biggify.
Step 2 is to wire up the Node:
- Connect a resistor from any of the analog pads (1,2 or 3) to Gnd
- Connect the signal wire (yellow in this case) to the pad, in this case 3.
- Wire up the senor’s ground and power.
Finally, make sure that your Node is set to 10 second operating mode. (Summary: Short ISP 3 to ground and reset).
Now connect your Arduino with the Wicked Receiver to your computer, and turn on the serial monitor. You should be receiving the sensor data.