The Engagement: Fireflies in Mason Jars

Hey All, Phil here. So the proposal happened actually just a few weeks ago, Friday, Sept 30, the day after Sunny's birthday. I had planned for weeks how I was going to do it. I knew that Sunny loves lightning bugs so I rigged up a series of 5mm LEDs and put them in mason jars (also one of Sunny's favorite things). I placed about 20 of them all around a dark room and proposed by candlelight and "lightning bug light". The effect was better that I imagined it was going to be (having never seen the end product anywhere but in my head) and it got an emotional and emphatic head nod when I finally asked the question.

Cost:
I turned to eBay for most of my materials. If you're willing to wait for overseas shipping, you can find things that cost less than the price to ship them.

• 5mm Green-Colored LEDs (100pcs) - $2.99 + free shipping (Hong Kong)
• Pencil Tip Soldering Iron - $5 w/ shipping
• Tin "Soldering" Solder - $0.99 + free shipping (Hong Kong)
• (470 Ohm) Resistors (50pcs) - $1.95 + free shipping (I didn't end up using these, but they should be used in most electronics projects)
• "9V Snap" Battery Clips (20pcs) - $4.30 w/ shipping
• 9V Batteries (8-pack) - $9 w/ shipping (Since I needed 18 I had to buy 10 more at the last minute for $20 at the store... moral of the story, use the internet to buy things if you have the time to wait)

So that comes out to under $25 for the electronics.

"The works"

 The rest of the project consisted of a hot glue gun (already had), some crafting moss (which I got at Wal-Mart - you could just go out into the woods and get the real thing, I was pressed for time) and some really old mason jars I got out of my parents' basement and cleaned up.

The Project:

Note: Use proper safety precautions when using a soldering iron, and consider ventilation - the solder smokes.

I used 5mm green LEDs, the perfect size and color for this project.

The LEDs have two prongs (or leads): the positive (long prong) and the negative (short prong). First I bent all the positive leads at a 90 degree angle to make sure my circuit would go the right way.

Bend the long (positive) leads at a 90 degree angle

After letting the iron heat up (note: always use a damp sponge to clean burnt solder off the iron throughout the project), I added a little solder to a positive lead then soldered that lead to a negative lead of another LED. I gave them a few millimeters of overlap to insure a good strong connection.

Add a little solder to one lead at a time.

A couple millimeters of overlap creates a good bond.

When I started doing to project, to make sure I was soldering the circuit correctly I put the battery connector on the battery and would touch the leads with the connector quickly (you don't want to burn out the LEDs) to see if they lit up. I soldered four LEDs together, negative to positive with two open ends to solder to the connector leads. I used four because that seemed to be the magic number to get the brightest shine without burning out the LEDs with my 9-volt battery. (I started using the resistors at first, which are meant to prevent overloading the circuit, but it limited my voltage too much so I scrapped them.)

I soldered the remaining positive (long) lead to the red wire on the battery connector and the remaining negative (short) lead to the black wire. Be sure that the connector is not snapped onto the battery while soldering.

Remember: red to positive lead, black to negative lead. If you get it wrong at first, just melt the solder and try again.

Snap on to your 9-volt battery and you have fireflies ("lightning bugs"). Now you can bend the leads to make a design if you wish (just don't cross the leads with each other).

Now I used a hot glue gun to fix the battery to the cap of a mason jar and eased the wiring into the jar. But in the end, it seemed to work just as well to set the battery down in the moss and let the LEDs "float" on the wiring. (Be careful, though. This could be a fire hazard.)