The purpose of our project is to create a musical boxing machine that allows users to practice boxing by pressing the button in sync with the rhythm of the music. This concept was inspired by a product found on internet sites. Our machine also enables users to upload their own music via an accessible SD card. Furthermore, it is designed to be easily powered by an external source and features a jack output for listening to music during training.

Material :

• 1 Board MDF 7mm
• 1 Borde PMMA 3mm
• 4 Force Sensitive Resistors (FSR)
• 1 Adafruit « Music Maker » MP3 Shield for Arduino
• 200g TPU 95A
• 5V Led Strip
• Arduino Uno R3 Card
• SD card
• 4 9.1KOhm Resistance

Model :

The design of the model underwent careful consideration of multiple criteria, given its exposure to force. Priority was given to boxer safety, necessitating the selection of appropriate button materials and the provision of ample space both between and within the buttons. It was crucial to avoid any protrusions of wiring or sockets from the button’s side to prevent injury. To safeguard the machine from damage, a sufficient margin in height was incorporated to allow for impact rebound without risking breakage. Furthermore, space allocation was dedicated to accommodate the wiring of force sensors, LEDs, and the music module. Rather than leaving empty space, pathways were purposefully created to guide the wiring, ensuring a tidy and efficient layout.

The button :

Experimenting with TPU 95A and TPU 82A involved an extensive process of trial and error. We experimented with various parameters, including thickness and retraction speed, during the printing process. Additionally, we iterated on the design to accommodate wire ingress and egress from the button, while ensuring there was ample space for an adult-sized punch. This iterative process allowed us to refine the design and printing settings to achieve optimal performance and functionality.

Sensor activation :

We also engineered a mechanism to absorb the impact of the button press by calculating the relaxation of the button. We designed a component to be affixed to the center, which will strike the central point of the button upon impact. The base attached to the underside of the button was intentionally enlarged to enhance the contact surface area. Careful consideration was given to the length of this component to ensure it does not impede the punch, cause injury to the player, or damage the sensors.

The electric circuit :

The primary electrical components, as previously mentioned, include four sensors, the LED strip, and the music maker module, all interfaced with the Arduino board and powered by a common power supply.

Force Sensitive Resistor (FSR) :

The force resistance sensors were employed to detect physical pressure, prioritizing simplicity over precision, as our system only required binary detection of force presence. Their wiring configuration involves three outputs: one connected to the resistance and directed to ground, and another defining the pin of the sensor, both originating from the same end. On the opposite end, the power supply connection is established. Given the low power consumption and the limited number of sensors (four in total), it is deemed safe to draw power from the Arduino board. To optimize space on the board, we consolidated the wiring by soldering the four power and ground ends together.

LED strip :

Managing the LED strip was quite challenging, requiring meticulous soldering to maintain a tidy layout and ensure correct wire connections while considering current polarity. Fortunately, the wiring aspect was relatively straightforward, involving connections for ground, power supply, and data entry. These digital LED strips are individually addressable, thanks to built-in driver chips. Due to space limitations, we had to optimize our layout and forgo a separate power supply, relying solely on the Arduino’s power source. To mitigate potential risks associated with supplying power to 75 LEDs over the long term, we securely soldered the LED strip to the bottom of the Arduino board, directly accessing power from the source.

Music Maker :

The Adafruit « Music Maker » MP3 Shield for Arduino played a pivotal role in our selection of the Arduino UNO R3, as it seamlessly integrates with it, as depicted in the image below. While this choice limited our options, preventing us from utilizing WiFi or Bluetooth connections, it provided essential features such as a jack output and an SD card slot. The Adafruit library accompanying the shield offers an extensive range of functions and comprehensive documentation, facilitating ease of use and integration. For detailed tutorials on utilizing the shield, one can refer to the following link: https://learn.adafruit.com/adafruit-music-maker-shield-vs1053-mp3-wav-wave-ogg-vorbis-player .

The general circuit :

Due to the stacking of the Music Maker shield on top of the Arduino board, additional cables needed to be soldered directly to the Music Maker module itself.

Code :

Difficulties :

Multiple iterations of the project were undertaken, each with its own concept and design. However, despite progress made in each iteration, they always seemed to fall apart in the end.

Arduino placement :

Initially, we thought the best spot for the Arduino was smack dab in the middle of the machine, with the power supply up front. But we soon realized that setup wasn’t exactly safe; one wrong move and you could whack a cable while playing.

The shape of leds :

The idea was to have hexagonal led strips around each button. The concept seemed flawless but the welding process took several hours and ultimately did not work. Apparently, it only takes a soldering pro 32 hours to realise there was a short circuit.

Conclusion:

The project is functional . To play the game, the machine should be connected to a power supply and to a jack output . The sd card can be accessed and changed to add more songs, altough the name of the added track should be adjusted. The game starts when you hit a random button and the goal is to not miss the hit and get it before the timeout and you will know if u did or did not get it on time. At the end, you will know if you won or lose the game.

We hope that this was insightful and if you were to want to recreate it, we wish that you could enjoy the experience as much as we did.

Hit with precaution

Amira Elouazzani and Malek Mkadem