INSTRUCTIONS
OVERVIEW
3 Basic Steps
STEP 1:
Purchase and prepare materials
STEP 2:
Strip, plug in and connect wires
STEP 3:
Run code and play certamen!
MATERIALS
Approximate Cost: $67 (without taxes)
ARDUINO UNO
Approx. $10
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12 RESISTORS, 10KΩ
Approx. $2
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BREADBOARD BUS STRIP
Approx. $4
Can be half-sized (only 30 rows)
75-100FT OF 22AWG 3 WIRE CABLES
Approx. $20
Cut into 12 equal length pieces
13 TACTILE PUSHBUTTONS
Approx. $6
Make sure there are 4 prongs on the bottom, preferably 4 different colors (preferably green, blue, yellow and another color), 3 groups of 4, and a single button in a different color
16X2 (1602) LCD WITH I2C INTERFACE
Approx. $3
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BREADBOARD JUMPER WIRES (28 MALE TO MALE) and (4 MALE TO FEMALE)
Approx. $2
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PLIERS
To clamp connectors and cut, and strip wires
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USB 2.0 A TO B CABLE (MALE TO MALE)
Approx. $1
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36 BUTT CONNECTORS, 17MM
Approx. $6
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36 FEMALE WIRE CONNECTORS, 17MM
Approx. $10
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DEVICE
Any device with a USB port that is capable of running Arduino Create
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BOX
Can be any kind of box that is at least 7"x5"x6", and has holes for the LCD, reset button, power cable, and certamen button cables
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SCHEDULE 80 1/2" PVC PIPE
Approx. $4
Cut into 5 equal length sections
DUCK TAPE & HOT GLUE
To keep wires in place, and glue buttons in PVC pipe
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FULL INSTRUCTIONS
Step 1:
First, make sure the LCD is working. If you flip the LCD over you should see a small board soldered onto the LCD. Look for 4 pins on the right. Plug in the female end of a black breadboard (male to female) jumper cable on the ground (GND) pin, plug in the male end to the ground pin on the Arduino. Then plug a red breadboard (male to female) jumper cable on the VCC pin on the LCD to the 5V on the Arduino. Connect 2 more cables from the SDA and SCL pins on the LCD to the SDA and SCL pins on the Arduino accordingly. Upload and run the code below. The screen should say "Certamen Machine".
Step 2:
Now that we know the LCD is working, we can start building the certamen machine. You want to start by stripping both ends of the 3 wire, 22 AWG cables, and one end of 24 male to male breadboard jumper cables.
Step 3:
After you have stripped the wires the next step is to connect them. Use the 2 diagrams above as references. 12 buttons are going to be used for the certamen teams. For each of these buttons you will need to wire the cables exactly the same, so you will have to repeat this process 12 times. At the base of the 22AWG cable, the part that will connect to the box, you will want to crimp, using the 17 mm butt connectors and pliers, a breadboard (male to male) jumper cable onto the ground (black) cable, and another onto the power (red) cable. These breadboard jumper wires will later go to the breadboard bus strip. On the third wire, which may or may not be green, crimp a 10k ohm resistor. At the other end of the cable, attach a 17 mm female wire connector to each wire. Crimp the power (red) and ground (black) both on the same side of the button. Crimp the third wire directly across from the ground. You can also opt to wire the buttons after inserting the machine in the box if you want the wires to fit better through holes in the box.
Step 4:
You will now need to use the 2 last female wire connectors to connect 2 breadboard jumper (male to male) cables to the same side of the last push button. This last push button will be the reset button. Use the diagram above to start wiring. You will need male to female breadboard jumper cables to wire the LCD. The LCD should be wired using SCL and SDA as in step 1. Use male to male breadboard jumper cables to connect the 5V pin to the red strip, and one of the ground (GND) pins to the black strip.
Step 5:
Insert the opposite end of the resistor that has been crimped together with the ground wire of the cable to a pin on the black strip of the breadboard. Insert the breadboard cable that has been crimped together with the red power wire of the cable to the red strip of the breadboard. Leave the green wire for now. The wiring may start to look like a mess at this stage. I had the problem of some wires popping out of the breadboard, so I duck taped both sides to keep it all in place.
Step 6:
Next you will want to start inserting the breadboard wire crimped together with the 3rd differently colored wire of the cable into the pins of the Arduino. Start at pin 2, the first 4 pins, pins 2-5 will be the green buttons. You will want to label each button as you go. So the cable with the wire that goes to pin 2 will have a green button, and labelled 1. Once you get to pin 6, start with the blue buttons. The button going to pin 6 should be labeled 1. Once you get to pin 10, start with the yellow buttons, label as previously. You should finish at pin 13.
Step 7:
Now you can finally test the certamen machine! Run the code below, this is the final code for the certamen machine. If it says "reset waiting" that means all of your connections are good, if it says "G1 pressed, please reset" and you haven't pressed the green button labeled 1 that means there is a loose connection in that cable. Try to identify and fix the loose connection. Once you think you have fixed it, press the reset button, the button that was labeled separately. The machine should say "reset, waiting..." again, if it doesn't there must still be a loose connection. When you do press a button, the machine should then say "G(the first letter of the color, in this case green)1(noting it is the first of the four buttons in that color) pressed, please reset."
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Step 8:
Insert the certamen machine into the box, and make sure the wires come out of the box you want it to. Then, hot glue the buttons to the PVC pipe. Make sure to keep the Arduino running, in case a loose connection forms. The buttons may not fit into the PVC pipe, depending on what size they are, so you can hot glue then on top.
Step 9:
Close the box, I had to hot glue it because the wires were pushing it open, and the certamen machine is done!