Here’s the circuit schematics for the Simon game’s input/output. We put four LEDs as output, and each LED was wired as an input as illustrated above. Transistors were used here for two reasons: we might have all four LEDs on at once, and transistors can handle all that current while the A3BU might not. Also, the LEDs from Adafruit ran on 12V, and the A3BU’s 3.3V would not light them. (We discovered that these LEDs have an integrated resistor, that’s why 12V doesn’t blow them up). The transistor can be connected to the ground side, and will switch fully on at 3.3V, completing the circuit through the LED to ground.
The project code is available at our github project repository.
Continue reading How the Simon Game works
The goal of this project was to combine transistors, interrupts, and LEDs with the Atmel A3BU microcontroller. It’s a simple push-button Simon Says game. The user watches a developing LED sequence, and then has to repeat it correctly to move onto a more difficult sequence that’s faster with more steps! The project combines the knowledge of embedded systems with circuit and programming skills we have learned throughout the semester. The code determines the sequence of lamps to light, and reads the user input, deciding what to do next. Events are interrupt-driven: user inputs trigger an interrupt handler that makes the next move. The hardware side of the project consists of interfacing the a3bu board with arcade-style push-button lights. The output portion of the circuit must raise the voltage level for the lamps, and the input circuit must provide voltage to the board input when a button is pressed. Ultimately, a working Simon game must have both the hardware and software components working perfectly.
This final project was an 8 bit music player using the Atmel A3BU Xplained board. A small piezo buzzer played one of four different songs; this project was more heavily tilted toward software than hardware. If you want to learn interrupts, this is the project for you! Interrupts were used to respond to buttons for selecting, playing, and pausing songs. Pulse Width Modulation was used to control the pitch. This project demonstrates good programming practices by creating functions for common tasks. A playNote() function was created which played a note based on given octave and length. The delay_ms() function was used to set the note length. The octave notes of each song were stored in an array, then passed on to the playNote() function, leading to a very compact file. When a song is played, the song title, number, and song status is displayed on the LCD screen.