Lesson Plan


This little weevil was designed and built as an educational kit by SparkFun.

Students will learn about electronic components and electrical circuity by participating in the active soldering of a small project. This centers around the Sparkfun Weevil.

Core Science Foundational Learning

  • Electricity
  • Base problem solving

Electrical Components

  • PCB
  • Red 5mm LEDs – 2x
  • 47k Ohm Resistor
  • 220 Ohm Resistor – 2x
  • Transistor
  • Miniature Photocell
  • Coin Cell Battery Holder
  • 20mm Coin Cell Battery

Additional New Vocabulary

Polarized components
Soldering iron

Important Safety Concerns

The soldering tip gets very hot and will burn. It’s hot enough to melt metal. Don’t touch it.

Solder is often made up . If your body absorbs this, it can be bad over time, so remember to wash your hands after soldering.

Wear eye protection when cutting the leads off. They become projectiles!

Electricity Basics

Electrons have an easier time flowing through metal, which is a material called a conductor. It circuit needs to be continuous, and electrons should flow only where it is supposed . When soldering, important that care it taken. If too much solder is used, it can cause a short – called as such because electricity can take a shorter path than it is supposed to go.  If it bypasses intentional components, it could send too much voltage into the system.

Steps to Successful Soldering

Situate the side of the tip of the iron so it is touching both the pin and the metal ring.

After a few seconds, touch the solder to the warmed pin (not to the soldering iron, to the pin/lead).

If properly heated, the solder will melt around the pin and create a good connection between the pin and the PCB.  It should look like a little volcano.