Introduction: Alligator Clip Jumper Wire for LilyPad Arduino

While prototyping with my Lilypad Arduino, I wanted to use a breadboard. I started just clipping some alligator test leads (attached to the Lilypad) to the jumper cables (in breadboard), but my workspace could get overcrowded with wires, and quickly. Also, I will do this frequently, and. I don't always want to reprogram my regular Arduino board because they are slightly different. It's just not efficient.

Solution: Alligator jumper wires.

I thought someone would have invented this already. I think I came across something like this in my internet reading, but it was an aside. I put this Instructable together to share how I did it in case it helps anyone else.

Step 1: Materials

  • Alligator test leads - mine were 12"
  • Straight male snappable header
  • heat shrink tubing - I think I used 3/8", big enough to fit over plastic on header pin


  • solder and soldering iron
  • wire strippers
  • heat gun (or lighter)
  • scissors
  • third hand if available (or person, props etc to help with soldering)

Step 2: Making the Cable

  1. Start by cutting your alligator test lead in half. Strip off a little under 1/4" or 4mm off each cut end.
  2. Clip one of the male header sections off the strip.
  3. Set up your test lead in one of the clips in a third hand. Set up the clipped male header in the other. Try to line them up nicely (as shown) to make for easy soldering. Apply some solder. Remove from third hand and inspect.
  4. If everything is how you like it, cut about 1/2" or 1.5cm of heat shrink tubing. Insert end of cable so that heat shrink covers the black nobby part of male header - but not overlapping edge by much. Heat up using a heat gun, lighter, candle etc., and get it nice and snug, particularly at the edges. The heat shrink will keep it all together and sturdy if snug.

Step 3: Try It Out

Try your cable out. It should connect to anything at the alligator end, and a breadboard at the other. In my case, it connects between my Lillypad Arduino and a breadboard. In this photo I have 4 of my new alligator jumpers connecting to the breadboard. It's not always necessary, but sometimes is.