Revision as of 07:44, 11 December 2022

Grading Criteria

Bow and Arrow

Abstract

Bow and arrow is a fun, aiming archery game. Our goal is to produce a similar version of ‘Bow and Arrow’ where the archer aims the arrow at the targets (balloons) using the bow. The game would have different levels and the archer would get 3 lives to score maximum points. As the level increases the challenges and speed of the game increase. In the later levels, there would be monsters coming onto the archer. In the later levels, there would be monsters coming onto the archer, and the archer should make sure he dodges those obstacles to save his life and hit the balloons to earn points. This is all displayed on the LED matrix acting as the screen.

Objectives & Introduction

The main objective of this project was to create the “Bow and Arrow” video game displayed on a 64X64 RGB LED matrix, with one SJ2 board as a graphics processor/matrix controller, and another SJ2 board as a controller. Other objectives are the following:

• Design custom PCBs for both the gamepad and matrix controller SJ2 boards.
• Use the FreeRTOS Real-Time Operating System on both SJ2 boards.
• Establish UART communications through Xbee between the two SJ-Two Microcontrollers.
• Create simple coding logic for displaying required characters and game objects.
• Add background music to the game to enhance the gameplay experience.

Team Members & Technical Responsibilities

• Shreya Kulkarni
  • Integrating of Graphics Driver
  • Game logic design
  • Joystick and button Implementation

• Pinky Mathew
  • Interfacing of LED Matrix and driver design
  • Game logic design and implementation
  • Graphics driver design and implementation
  • Joystick Integration

• Pushkar Deodhar
  • Zigbee module
  • Integrating MP3 module with the Game
  • Hardware Designing & PCB Integration

• Noel Smith
  • MP3 Audio Encoder/Decoder
  • Integrating MP3 player with the Game
  • Hardware Designing & PCB Integration

Administrative Responsibilities

Schedule

Bill Of Materials

Design & Implementation

PIN CONFIGURATION

RGB Led Matrix

The display in this project is a 64x64 RGB LED matrix panel with a scan rate of 1:32. The 4096 RGB LEDs in the LED matrix panel can each be individually controlled and addressed. The SJ-two board does not have enough GPIOs to support 4069 LEDs, so this LED Matrix uses just 13 digital GPIOs to provide complete control of each individual LED. The LED matrix does this by using a decoder to pick the rows and a 64-bit shift register to enable the desired color on the selected column. Data is placed into the shift register to choose the columns when the row selection is low. In this 64x64 LED matrix, which has six 64-bit shift registers for R1, G1, B1, R2, G2, B2, each color of the LED is controlled by one bit of the shift register. The display can only display 8 colors because it uses daisy-chained shift registers, which prevents PWM from being used to individually control each LED. The 5:32 decoders are used to control the LED matrix's top (Rows 0-31) and bottom (Rows 32-63) halves, respectively, as shown in the diagram below. Each of the lines A, B, C, D, and E of these decoders, which are used for row selection, has a 5-bit input.

How to illuminate an LED in the matrix:

1. Represent the color you want to appear on the board using three bits.
2. Choose whether you want to light an LED that is on the board's UPPER or LOWER side, and then adjust RGB1 or RGB2 pins accordingly.
3. To set the bits and clock them in with the other LEDs, toggle the CLK (You can set the other LEDs to be off by clocking in zero)
4. Once a full row has been entered, disable Output and set Latch High.
5. Using the A, B, C, D, and E pins, indicate which row your target LED is on.
6. Reactivate the Output and lower the Latch's value.

LED selection

Elegoo Power Supply Module

We opt to use the Power supply Module that came with the ELEGOO Upgraded Electronics Fun Kit rather than independently powering the SJ-two board, led matrix, and MP3 decoder. This supply module takes input via a barrel jack from a battery, a 12V power source, or any other source, and outputs 5V to our circuit as needed. To power a solderless breadboard layout, this module offers a cheap and practical way to convert a 7-12V wall plug into 5V and 3.3V. 700mA is the maximum output current. One 5V connector will link to the SJ-two board's Vcc, and the 64x64 led matrix will be powered by 5V.

Power Module

LED Matrix and Controller Board Enclosure

From the boxes we had on hand, we created the enclosures for our controller board and LED matrix. We positioned our matrix at an angle to provide the player with the best possible immersive experience. The controller board is not linked to the matrix enclosure, allowing the player to sit back, relax, and play the arcade game relatively comfortably. The controller board has its own enclosure, and the XBee module is used to communicate between the boards.

MP3 Decoder

This module is a straightforward MP3 player that runs on the YX5300 high-quality MP3 audio chip. MP3 and WAV file formats with sampling rates of 8 kHz to 48 kHz are supported. The micro SD card used to store the audio files can be inserted because there is a TF card socket on the board. By sending commands to the module via the UART interface, the MCU can control the MP3 playback state by altering the volume, switching tracks, etc.

Serial MP3 Player

Hardware Design

The UART Tx, UART Rx, VCC, and GND pins are the 4 pins that the MP3 decoder module needs. The SJ2 board provided the module with the 3.3V it needed to start up. On the SJ2 board, UART1 pins have been set up so that commands can be sent to the decoder. This UART communication's baud rate is set at 9600 bps. Additionally, this decoder has a speaker-connected 3.5mm audio jack.

Connection diagram of MP3 decoder to SJ2 board.

Software Design

MP3 Initialization

MP3 Flowchart

Controller Board and Main Board Communication

You may quickly configure XBees, test connections, and pass data between your computer and remote XBees by connecting an XBee Explorer between your computer and your XBee and using the X-CTU software. We utilize X-CTU, free software offered by Digi (the XBee maker), to set up, manage, and test XBee networks. An excellent step-by-step instruction for configuring the Xbees as a transmitter and receiver can be found on the SparkFun website at here. The Xbee module, button press, and joystick make up the controller board. A joystick is used to control character movement, while a button is used to activate the shoot arrow. Using ADC, the joystick reading is captured. We must enable burst mode on the ADC, which performs repeated conversion at 400 kHz, rather than reading a single value each time. Then, using Xbee, this information is transferred from the controller board to the mainboard (which houses the game logic and led drivers). Data is sent over UART after being received at the receiver end. The joystick ADC reading is represented by bits A0-A6 of the UART frame, whereas the button press data is represented by bit A7 of the frame. Blank data is sent if the button is not pressed. When an ISR is called after a UART interrupt, data is sent into the queue. The task that was dormant in the queue now awakens and, based on the data, moves the characters.

Depiction of Communication Between Boards

Game Controller reading data from joystick and sending to UART logic

void read_joystick_and_send(void *p) {
  while (1) {
    uint16_t joystick_reading = adc__get_channel_reading_with_burst_mode(ADC__CHANNEL_2);
    joystick_reading = (joystick_reading * 125) / 4095;
    if (!(LPC_GPIO1->PIN & (1 << 31)))
      joystick_reading |= 1 << 7;
    uart_lab__polled_put(2, joystick_reading);
    vTaskDelay(5);
  }
}

Configuring Xbee

You will most probably have to configure your XBee with XCTU softwarelink and using the board link, before interfacing XBee with SJ2. Refer to this video link to initially configure XBee. You will have to connect XBee with the board to your PC for configuration.

Game Logic

write game logic here --> "pinky"

In our Bow and Arrow project, the command we use plays the song by navigating to its index on the SD card. In our code, the function that sends this command is referred to as play music at index. We must first send the command [Select device] before we can send the instruction to play music at a specific index. The datasheet specifies that you should send "7E FF 06 09 00 00 02 EF" since Serial MP3 Player only accepts micro SD cards. Additionally, the function uart polled put on UART1 is being used to transmit the commands.

Game logic

Testing & Technical Challenges

Describe the challenges of your project. What advise would you give yourself or someone else if your project can be started from scratch again? Make a smooth transition to testing section and described what it took to test your project.

Include sub-sections that list out a problem and solution, such as:

<Bug/issue name>

Discuss the issue and resolution.

Conclusion

This project was a huge success and a valuable teaching tool. Every module used for the project was effectively integrated, and we were able to reproduce our original game concept. The LED matrix was able to play the noises for each of the game components while loading our character moving, jumping, and separating balls. We also demonstrated our life and score tracking logic during the event. We encountered a number of challenges while working on the project, including issues starting the LED matrix driver, figuring out how to incorporate ballon and arrow collision detection, creating multiple ballons and creating randomly positioned balloons in level 2, designing and maintaining our complex game logic state machine, and much more. We were able to understand the real-world use of FreeRTOS while working on our project. We came to the conclusion that defining weekly goals and exceeding them could assist compartmentalize the project and eventually meet the desired outcome. This project improved our proficiency with embedded software and consolidated our command of it.

Project Video

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Project Source Code

• github repository link[1]

Acknowledgement

We would like to thank Professor Preetpal Kang for sharing his knowledge and insights with us during the course of the project. 

References Used

1. Serial MP3 Player Datasheet
2. Binary code pattern generator for LED Matrix
3. Everything You Didn't Want to Know About RGB Matrix Panels

Appendix

You can list the references you used.