Make the Gadget

To make this device, we’ll start by constructing the probe that you’ll dip into water samples to get a conductivity reading—which we created by repurposing a binding post (Radio Shack catalog #274-718) typically used in home audio/video and ham radio electronics. It may seem like a complicated build on first glance, because there are several steps involved. But it’s mostly a straightforward matter of connecting wires to the binding post—as you can see in the photo of the finished probe.


  1. Arduino
  2. Breadboard
  3. 10K resistor
  4. 8-ohm speaker
  5. 4Char display
  6. Chassis-mount dual female binding post (RadioShack catalog #274-718)
  7. Jumper wires in various colors
  8. Several feet of insulated solid core wire
  9. Small piece of aluminum ...

Get Environmental Monitoring with Arduino now with O’Reilly online learning.

O’Reilly members experience live online training, plus books, videos, and digital content from 200+ publishers.