Prototype an Electronic Coin-toss Prep: Specs, Parts, and Tools - dummies

Prototype an Electronic Coin-toss Prep: Specs, Parts, and Tools

By Doug Lowe

For this project, you create an electronic version of a coin toss. Instead of flipping a coin into the air to see if it lands heads or tails, you build an electronic device that does the coin toss. That way, you can make decisions even when you’re penniless.

The specifications for the coin-toss project are as follows:

  • The device will have two LED indicators to indicate heads and tails.

  • It will also have two small metal contacts, which the user can touch with his or her finger. When the user touches both of the posts, the LEDs start flashing, alternating back and forth, much like a coin flips end over end when you toss it into the air.

  • When the user removes his finger from the two metal contacts, one of the two lights will stay lit, indicating whether the result of the coin toss is heads or tails. Which light stays lit will be essentially random.

  • To conserve battery life, the device will have an on/off pushbutton. The user must depress the pushbutton to make the device work; when the button is released, the device is turned off.

  • The device will be battery powered and contained in an enclosure small enough to hold in your hand.


All the parts required to build this prototype circuit can be purchased from your local RadioShack, or you can order them online from any electronic parts supplier. For your convenience, here is a complete list of the parts you’ll need to build this prototype circuit, along with the RadioShack catalog part numbers:

Part Number Quantity Description
276-003 1 Small solderless breadboard
276-173 1 Solderless breadboard jumper wire kit
276-1723 1 LM555 timer IC
271-1321 1 1 kÙ, 1/4 W resistor (5 per package)
271-1335 1 10 kÙ, 1/4 W resistor (5 per package)
271-1317 2 470 Ù, 1/4 W resistor (5 per package)
272-1053 1 0.1 μF polyester film capacitor
276-041 1 Red LED 5 mm
276-022 1 Green LED 5 mm
270-325 1 9 V battery snap connector
n/a 1 9 V battery

You can build this circuit using equivalent parts from any supplier. So if you already have equivalent parts on hand, you don’t need to run out to RadioShack and purchase them just for the sake of spending money.

You won’t need many tools for this project. You can probably assemble it without any tools at all, but you may want to keep your wire cutters, wire strippers, and tweezers handy.