Are there any friends interested in the project below?
1. Core Components and Cost List
| Component | Recommended Solution | Estimated Cost |
|——————-|———————————–|—————-|
| Main Structure | Inflatable punching bag/sandbag + homemade target | 50-150 CNY |
| Impact Detection System | Pressure sensor + foam cushioning layer | 40-80 CNY |
| Display and Interaction | Second-hand smartphone/Raspberry Pi + touchscreen | 0-150 CNY |
| Main Control Chip | Arduino Nano/ESP32 development board | 20-50 CNY |
| Voice Feedback Module | WT588D voice chip + speaker | 15-30 CNY |
| Power Supply System | 5V mobile power supply + voltage regulator module | 20-40 CNY |
—
2. Step-by-Step Production Guide
1. Building the Main Structure
– Option A (Low Cost): Use an inflatable sandbag weighted at the bottom (filled with cement), and cover the surface with EVA foam board as the striking area.
– Option B (Recyclable): Fill a plastic barrel with sand + old clothes, and fix a spring on top to enhance rebound.
– Target Design: Use 3 silicone buttons (corresponding to options A, B, C), with a thin film pressure sensor embedded inside.
2. Building the Circuit System
– Main Control Connection Diagram:
“`
[Pressure Sensor] → [Voltage Divider Circuit] → [Arduino Analog Input]
[Touchscreen] → [SPI Interface] → [Arduino]
[Voice Module] ← [PWM Pin] ← [Arduino]
“`
– Key Code Logic:
“`arduino
void loop() {
if(detected_hit) {
int option = analyze_hit_position();
if(compare_with_answer_bank(option)) {
play_correct_sound();
score++;
if(score % 50 == 0) trigger_confetti();
} else {
play_incorrect_sound();
score–;
}
update_display();
}
}
“`
3. Function Implementation Techniques
– Anti-misfire Design: Add rubber rings around the sensor, set a 500ms trigger cooldown time.
– Dynamic Question Bank: Use a MicroSD card to store a CSV format question bank (fields: word, definition, distractor 1, distractor 2).
– Enhanced Feedback: Use WS2812B LED strip to highlight options, with red light pulsing when incorrect.
—
3. Cost Optimization Suggestions
1. Alternative Material Solutions:
– Use an old Android phone instead of a touchscreen (install Termux to run Python scripts).
– Use pressure sensors from kitchen scales (about 5 CNY each on Taobao).
– Create an adjustable stand using PVC pipes and universal joints.
2. Modular Design:
“`mermaid
graph LR
Core Control Box–>|USB|Display Terminal
Core Control Box–>|Dupont Wire|Impact Sensor
Core Control Box–>|Audio Cable|Feedback System
“`
3. Safety Protection:
– Cover the striking surface with 2cm thick high-density foam.
– Isolate the circuit system with an acrylic box.
– Set up an emergency reset button.
—
4. Advanced Upgrade Directions
1. Data Tracking: Add a Bluetooth module to sync practice data to a mobile app.
2. Adaptive Difficulty: Dynamically adjust the question bank level based on accuracy (C language implementation example):
“`c
int adjust_level(int current, float accuracy) {
return (accuracy > 0.8) ? current + 1 :
(accuracy < 0.5) ? current – 1 : current;
}
“`
3. Multiplayer Competition: Implement a two-player battle mode using infrared sensors.
—
5. Production Cycle Planning
1. Prototype Stage (3 days): Complete basic impact detection and single question feedback.
2. Function Integration (5 days): Implement question bank access and scoring system.
3. Optimization and Debugging (2 days): Address sensor sensitivity and structural stability.
4. Aesthetic Enhancement (optional): 3D print a shell or spray paint for decoration.
> Note: It is recommended to first create a 1:3 model with cardboard to test structural feasibility before using formal materials. The core code is recommended to be developed in the PlatformIO environment, which is easier to manage dependencies than the Arduino IDE.