Latest revision as of 03:56, 15 December 2022

Traditional Bow and Arrow Game on Windows

Bow and Arrow

Abstract

Bow and arrow is a fun, aiming archery game. Our goal was to create a similar version to the 1992 arcade game 'Bow and Arrow,' in which the player takes on the role of a skilled bowman on a quest to fight the dreaded Black Archer. There are two levels in our game. The challenges increase as the level advances. The player shoots the arrow at the balloons with a joystick. Before the arrows run out, the player must acquire a WIN SCORE. There are also rocks and three lives on the second level. When the player hits the rock, he loses one life. An LED matrix displays the entire game.  In addition to visuals, the game has sound effects achieved using MP3. There is no timer in this score-based game. Enjoy the Game!

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:

• 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.
• Design custom PCBs for both the gamepad and matrix controller SJ2 boards.

HOW TO PLAY BOW AND ARROW:

The main aim of the game is to burst all the balloons and advance to the next level.

• Using the joystick on the game controller, move the bow up or down.
• Shoot arrows by pressing the joystick to burst the balloons.

Level 1

• Achieve a target score of 45 with the 10 provided arrows.
• If not game is over and the player can restart the level.
• If the level is won, press o start level 2.

Level 2

• Avoid hitting the rocks to not lose your life.
• Achieve a target score of 45 with the 10 provided arrows.
• If not, the game is over and the player goes back to level1.

Team Members & Technical Responsibilities

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

• 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 and Joystick Driver design
  • Integrating MP3 module with the Game
  • Hardware Designing & PCB Integration

• Noel Smith
  • MP3 Audio Encoder/Decoder Driver design
  • 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, and 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.

Enclosure Front View

Enclosure Side View

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 Music

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.

System Diagram

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

The game starts at level one. The balloon creation task in level one produces repeated sets of four balloons until the player earns WIN SCORE (45 points) or runs out of arrows. Initially, there will be 10 arrows displayed in the upper right corner, and the count decreases with each arrow shot. The collision function, which is invoked by the shoot arrow task, checks to see if the arrowhead coordinates intersect with the balloon. If collided, the balloons turned black. For a full set to display again, one must shoot all four balloons. The player can advance to level 2 after scoring 45 points in 10 arrows.

The game's complexity is increased in level 2. In addition to randomizing balloon placement, we've also introduced rock-shaped impediments as a further challenge. There will be three lives available. If the player strikes the rock, the life count drops. Additionally, a player's score rises as they hit the balloons. The level is won if the player achieves a WIN SCORE (45 points) with fewer than or equal to ten arrows and fewer than or equal to three lives. To make the game more pleasant, we've limited the number of arrows to ten.

Game Logic

We have implemented the collision logic for the balloon by the condition i.e. (if the arrows head coordinates are lesser than equal to than balloon's start row plus the balloon's height and arrowhead coordinates are lesser than equal to the balloon start column plus the balloon width), balloon collision is detected and player's score is increased by 5 points per each balloon. So if the balloon_is_collided condition is true then the balloon disappear function gets called making the balloon color black. Concurrently game score task is called and the score gets increased by 5 points. The same logic is followed in level 1 and level 2.

Collision Logic of Ballon

For level 2 as we have added rocks, the rock hit logic is implemented such that if the rock start row is lesser than equal to the arrowhead coordinates which is also less than the rock start row plus rock height, and the rock start column is lesser than equal to arrowhead coordinates which is also lesser than rock start column plus rock width --> rock collided is detected and lives count is reduced by one out of three. If the rock collision is detected, the rock disappears function is called and as the live count is reduced, the make life disappears function will also get executed.

Collision Logic for Rock

In our Bow and Arrow project, the command we use to play the songs is by navigating to its index on the SD card. In our code, the function that sends this command is referred to as playing music at the 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.

Scoring

LEVEL 1 score logic

LEVEL 2 score logic

Game Tasks

The figure below shows the FreeRTOS tasks that have been used in the Bow & Arrow game.

Testing & Technical Challenges

1. Along with the LED matrix and MP3 decoder, we have also wired the Xbee receiver directly to SJ2 using a pin-to-pin connection. The LED matrix screen would occasionally not turn on, but if we detached and reconnected the GND wire of the Xbee receiver, it would.

2. The 33rd row of the LED matrix was shown on the first row, which was a problem we ran into early on in the project. This problem arose because we failed to reset the LED Matrix's Output Enable pin before clocking in the subsequent row of data. After carefully reading the Sparkfun article on RGB Matrix Panels, we were able to address this problem.

3. Since our game has a lot of graphics, making a colorful, enjoyable screen was challenging and time-consuming. We discovered open-source software that, when receiving the photos as input, outputs a string of 1s and 0s. The gaming screens in our game are 2D matrices. The string of 64x64 characters required the painstaking addition of commas and braces to convert to matrices. Therefore, we created an automation script that, when the string is entered, outputs the final 64x64 matrix.

4. Rocks and balloons appear at random at stage 2, and overlapping was a significant problem. We created rows and columns (x and y coordinates) of balloons and rocks as members of structure object info. If the random number generator simultaneously produces pebbles and balloons, a new site must be selected.

5.Sounds get jumbled when a single file is edited individually. As sounds are referenced by folder and their index, the order gets ignored when sounds are saved individually. Rather, all the sounds need to be placed in SD card at the same instance. Else, they don't follow the order. The latest edited one precedes the older files.

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.

Appendix

Project Video

• Demo Video Link

Project Source Code

• Project Source Code

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