Making Things Interactive

February 27, 2008

Midterm Proposal: Fireflies in a Jar

Filed under: 7: Mid-Term Project,Assignments,Gee Kim — gskim @ 8:37 pm

Fireflies in a Jar is a teaching tool for children who can’t sleep in the dark. There’s going to be three differently programmed fireflies and a jar where the child can place them in. Before going to bed, the child can place as many fireflies into the jar and close the lid to activate the light. You can adjust the luminosity of the jar by putting more or less fireflies in. The light from each firefly will eventually fade out and turn off within a certain time span. The child at this point will either be too tired to put in more fireflies, and end up sleeping in the dark, or still be awake. Then they have the option of putting more fireflies in to reactive the light or sleeping in the dark.

The program of the fireflies. The three fireflies will have different programs that will mimic the light of a firefly. The LED will start with a high intensity light and gradually fade out and turn off. This is going to give the pupil time to adjust in the dark to see better. Each light will also be programmed to have different time span it to be on, keeping the fireflies spontaneous and fun for the child.

How will it work? Each firefly will have an LED attached to it. The fireflies will sit on its own on/off switch. Removing the firefly from the switch will let us know which firefly is being put into the jar and need to be on once the jar is closed. The jar will also have on/off switch, attached to the lid, that will tell us when the jar is closed. Once a firefly is placed into the jar, and the jar is closed, the program for that firefly will run as long as the jar is closed. If the jar opens and closes, with the same firefly in the jar, the program of that firefly will restart. This works with all the fireflies.

All the switches used in this design will have a digital read, and the LEDs will have a digital output according to its corresponding switch. The switches will have a HIGH and LOW digital read. The brightness of the LEDs will be controlled using the “for” program code in the Loop Setup, and the “if” program code will be used to activate each firefly.

Parts List: Arduino, 3 LEDs (white), 4 on/off switch, jar with lid, 9V battery, circuit wire, wiring tape.

How to go about this project…

Step 1. Wire and program LED 1

Step 2. Wire and program LED 2

Step 3. Wire and program LED 3

Step 4. Wire 3 switches. Place each LED on its corresponding switch, and program it to activate when the LED is off of the switch.

Step 5. Wire the switch for the jar, and program so that the LEDs turn on when the jar switch is pressed and when the LED is off of its switch.

Step 6. Add an interruption code to the program, for when the jar is opens and closes.

Step 7. Test run design for error (different combination of LEDs in jar, and when jar opens and closes, etc.)

Step 8. Assemble parts for presentation.


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