231a-ag progressnov17

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Progress Report (as of November 17)

Revised Arduino Schematic

231a-ag revisedArduinoschematic3.png

What I've Done



  • So, it turns out that SparkFun's keypad tutorial isn't all true (the diagram is completely wrong...), so I used a digital multimeter to test which "hole" combinations corresponded to which numbers on the keypad.

231a-ag multimeter.jpg

  • Then, it also turns out that the photo below (image courtesy of SparkFun's photo of the keypad) shows exactly what I tested for with the digital multimeter. It confirmed all the combinations I hypothesized, so the digital multimeter worked!

231a-ag keypad.jpg

  • Dominique and I discovered that digital pins 0 and 1 can't actually be used, so some rewiring had to be done. In the end, we decided to use the analog pins, because there aren't enough digital pins for all the inputs/outputs I have.
  • Dominique created the table drawn below, which shows that to use 9 keys (1, 2, 3, 4, 5, 6, 7, 8 and 9), I only need the keypad pins 1, 2, 3, 5, 6 and 7. Notice they're also in a funny order, so the wiring will be extra tricky.

231a-ag keypaddiagram.png


  1. Keypad pins (formerly called "holes") 1, 3 and 5 are using Arduino analog pins, and keypad pins 2, 6 and 7 are using Arduino digital pins. (This is because the numbers 1, 3 and 5 are never "paired" together, and 2, 6 and 7 are never "paired" together.)
  2. Keypad pin 1 goes to Arduino analog pin 1. Keypad pin 3 goes to Arduino analog pin 0. Keypad pin 5 goes to Arduino analog pin 2.
  3. Keypad pin 2 goes to Arduino digital pin 2. Keypad pin 6 goes to Arduino digital pin 4. Keypad pin 7 goes to Arduino digital pin 3.

231a-ag keypadwire.jpg

  • The image above is an older picture... I am no longer using Arduino digital pin 5.

231a-ag keypadwire2.jpg


  • I tested the LED matrix using a circuit board, and it works!

Questions/issues that are left

  • Code that makes it all go!