TIVA Ports

Below can be seen the pin assignments given to the Tiva headers pins. 

Recycle Basket Beam Break

Basket Lights

To detect the passage of an object through the recycle bin, a simple beam break circuit was utilized. This circuit is composed of a transmitter IR LED and a phototransistor receiver.

To turn on the basket lights, a 2N7000 MOSFET was used to toggle the lights on and off. Rather than soldering 20 LEDs together, a pre-made LED strip was used.

RainWater

The servo actuates the bucket (via the slider-crank mechanism) and is controlled using PWM. The linear slider potentiometer provides an analog input to the TIVA, indicating the angle to which the servo should move. The rainwater lights are LED strips that come in a package (LEDs + Resistances) that are controlled with IRLZ34N MOSFETs.

WhackALight

The WhackALight interaction was implemented using a tape sensor to detect the proximity of the hammer, a Schmitt trigger to condition the signal, and a MOSFET to toggle the lights. This design was repeated four times in the final TREE design. Below can be seen the circuit schematic for all four of the MOSFET toggled LED lights.

Below can be seen a single schematic for the tape sensor, the Schmitt trigger, and a voltage reference. This design was repeated for each of the 4 lights. Each sensor is connected to one of the indicated pins above in Port C, which is generalized to TIVA PC.

Start Button

The start button was a simple push-button switch. It was used to prompt the user to start the game.

Sound Board

The sound board was a prefabricated board bought from Adafruit. Sound files were uploaded via USB to the board, and the sounds were triggered by pulling the line corresponding to the sound low for 200 ms. The sound board's output was connected to a headphone jack.

LCD and Shift Register

To provide visual feedback of the total points acquired during the game, a small  LCD 16x2 character LCD screen was used. The LCD was controlled using a 8 bit shift register which was controlled with three lines from the Tiva. The LCD was also controlled in the 4-bit write mode. The LCD connections were connected to a header as shown.

Passage of Time

To indicate the passage of time, a servo was used to slowly lower a picture of a polar bear below another picture of the ocean. The user is prompted to complete the game before the polar bear sinks.

Flip Polar Bear

At the end of the game, a servo is used to rotate a sign from a horizontal to a vertical position. This sign contains a celebratory message congratulating the user on their performance.

Stamp

To stamp the LEAF, a pen attached to the arm of the servo was rotated until it made contact with the LEAF. This made a small round dot in the team 16 square of the LEAF.

LEAF Detection

To detect the insertion of the LEAF, a tape sensor was used. This sensor combines a IR led and a phototransistor. The Tiva was able to sense the change in input as the black square on the LEAF was inserted under the tape sensor.