231a-ag progressnov16

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Progress Report (as of November 16)

Revised Arduino Schematic

231a-ag revisedArduinoschematic2.png

What I've Done

LED Matrix


231a-ag ledmatrix.png

  • The pins required to light a "3x3" LED matrix using the colour green are: pin 18 (corresponds to column 3), pin 15 (corresponds to column 4), pin 1 (corresponds to column 5), pin 16 (corresponds to row 3), pin 13 (corresponds to row 4) and pin 3 (corresponds to row 5).


  • The last step performed for the wiring of the LED matrix (from Nov. 14 Progress Report), was "Connect these three wires to the breadboard, where it will eventually be wired to a resistor. "
  1. Connect the three 10 Kohms resistors to the breadboard.
  2. Take another 3 pieces of wire, and connect them to pins 18, 15 and 4 on the LED matrix. We do this because it is the "columns part" of the LED matrix that needs the resistors. Be sure that the resistor coming from Arduino pin 10 is going to LED matrix pin 18, the resistor coming from Arduino pin 11 is going to LED matrix pin 15, and the resistor coming from Arduino pin 12 is going to LED matrix pin 1.
  3. The "rows part" of the LED matrix does not need resistors. Therefore, take another three pieces of wire, and connect them from Arduino digital I/O pins 9, 8 and 7 to LED matrix pins 16, 13 and 5 respectively.

231a-ag wiredledmatrix.jpg



  • I used the photo below to figure out that the keypad doesn't use all its little "holes" to function - the two "outer holes" don't need to be wired. (Image courtesy of SparkFun's photo of the keypad.)

231a-ag keypad.jpg


  1. Wire each wire coming from the keypad pins (formerly referred to as "holes") to the appropriate Arduino pin. The schematic shows which wire goes to which Arduino digital I/O pin.


  • I found a 300 ohms resistor, and decided to use that for my buzzer instead of the 22 ohms resistor.
  • It looks almost done! (Maybe.)

231a-ag allwired.jpg

Questions/issues that are left

  • Do I really need the last "hole"? It is used only for the fourth row of numbers, which I won't actually be using in this project.
  • I need to write some code to test that the hardware works...