This is an idea I have had for a while and my entry for the USB Contest. I got the idea while taking apart a 9 LED flashlight from Harbor Freight Tools. A USB port is ideal for powering this because a USB port outputs 5V and the flashlight needs 4.5V. The only problem I can see with this is that 5V going into a 4.5V device will cause it to burn out faster than just running off batteries, but the LED module is cheap and easy to replace.
Because of the way the world is (mainly because I don't won't to be sued for some stupid reason), I am obligated to say this:
**Disclaimer. I am NOT responsible for what you do with this information. Do not do something stupid and hurt yourself or your computer.**
Step 1: What You Shall Need.
A Phillips Screwdriver (or something else sharp)
A Flat Head Screwdriver
A Soldering Iron (and Solder)
Desoldering wick* (not needed if you're careful)
A Helping Hands (these things are invaluable when soldering)
A Hot Glue Gun (and Glue Sticks)
A Mason Jar w/ lid (any jar w/ a lid would do, this is just what I had)
An old USB Cable
A 9 LED Flashlight from Harbor Freight.
A Switch (Optional. If you do include it, make sure it isn't momentary)
*Not pictured here was desoldering wick because I rarely need it.
I think that's it. Now Let's Get Building!
Step 2: Disassembly
First we have to take apart the flashlight. I chose to cut the case with a Craftsman Nextec Vibrating Multitool until the LED module popped out, as I just wanted to get the LED module out. Be careful though, as you don't want to break it.
After you get the LED module out, take your wire cutters and cut the female end off of the cable. If your cable doesn't have a female end, just cut off the end that doesn't plug into your computer. Also poke two holes in the top of the mason jar lid, one in the center and one off to the side.
Step 3: Reassembly
Step 4: More Reassembly
Step 5: Finishing Touches
Since yours works now, take your glue gun and glue the LED module to the jar lid. Don't cover up that second hole you made,otherwise the plant will suffocate. Then glue the wire down to the top of the jar's lid.
Step 6: Making Into an Actual Terranium
Take a few spoonfuls of your soil and put it into the jar. Dig a little hole into the soil and place your plant into the hole. Put a little more soil to bury the roots then add a little water. Screw the lid on and plug into your computer. If you put a switch on it turn that on. Now your done.
Enjoy your new USB Terranium!