Arduino Report #15: Project 20--Seven-Segment LED Double Dice

Additional Parts:

1. 2-digit, seven-segment common anode LED display x1
2. 100 kOhm resistor x1
3. 270 Ohm resistor x10
4. 1 kOhm resistor x2
5. BC307 Transistor x2
6. Push-to-make switch x1

Time to complete: 2 hours over several sittings

Earlier, I wrote about an LED Dice project that used seven LEDs to simulate the dots on a die. Today's project is very similar. Here, we are simulating the rolling of two dice with a 2-digit seven-segment LED. The dice roll when the push-to-make switch is held. This project took me an unreasonably long time to complete, but not because the project itself was difficult. The LED display I had did not have a readily available pin-out diagram and did not match the one provided in the book. Also, I found a shorting wire half way through the process. The excessive time comes almost exclusively from having to derive the pin-out diagram for the display and obsessively checking the wiring. The rest of the project took about 30 minutes to complete. 


The wiring of the LED display was a little cumbersome because my breadboard was too small for the project. In order to alleviate some of the cramped conditions, I found some longer wires to branch out to a second small breadboard. This helped immensely in troubleshooting the LED display. Having some space to work with in the circuit allowed for rapid testing of the pins. In the book, the LED display is connected directly to the Arduino through a single resistor from each pin. This would have made troubleshooting the display nearly impossible. 


When I showed my nine year old son this project, his response was "Didn't you already do this?" I guess he wasn't impressed. He did, however, inquire as to how I was able to generate the random numbers. He listened to my explanation for about five seconds before wandering off to pretend to battle with his brother. 


Below is a video of the working dice. 

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