Technical Questions
Hardware specifications and component choices
Why use Raspberry Pi Pico 2W instead of Arduino or ESP32?
The Pico 2W offers several advantages for this project:
- • Built-in Wi-Fi (2W model) for wireless control
- • MicroPython support (easier to program than C++)
- • Sufficient GPIO pins (30 total)
- • Low cost ($6-10 USD)
- • Native I2C hardware support
- • Good community and documentation
Note: You can adapt the project to use Arduino, ESP32, or even Raspberry Pi if preferred. The core logic is the same.
Can I use different servo motors?
Yes, but with considerations:
- SG90 (recommended): Cheap ($2-3), adequate torque for most builds, plastic gears (may strip under heavy load)
- MG90S (better): Metal gears, more durable, slightly more expensive ($4-5)
- Larger servos (MG995, etc.): More torque but requires higher current (may need 10A power supply)
- Digital servos: Work fine, but may prefer 60Hz PWM frequency
⚠️ Important: All servos must have the same voltage rating (5V). Mixing 5V and 6V servos is not recommended.
How much power does it consume?
Power consumption varies by activity:
- • Idle: ~0.5W (100mA at 5V) - just electronics
- • Moving 1 servo: ~2-5W (400mA-1A)
- • Moving all servos simultaneously: ~15-25W (3-5A)
- • Peak load: Up to 25W with 8 servos at maximum torque
A 5V 5A (25W) power supply handles 4-8 servos comfortably. For safety margin or larger builds, use a 10A supply.
Can I add more than 8 panels?
Yes! The PCA9685 supports up to 16 servos (panels). For even more:
- • Add a second PCA9685 board (different I2C address)
- • Connect to the same I2C bus
- • Update software to address both boards
- • Scale power supply accordingly (10A for 16 servos)
Practical limit: 16-32 panels before mechanical complexity and cost make it impractical.
Why not use stepper motors instead of servos?
Servos were chosen for several reasons:
✓ Servo Advantages:
- • Integrated position feedback
- • No external drivers needed
- • Easier to control (single PWM pin)
- • Lower cost per unit
- • Compact size
✗ Stepper Drawbacks:
- • Requires driver boards (A4988, TMC2208)
- • More wiring complexity
- • Higher cost
- • Need endstops or encoders
- • More mechanical parts (gears)
Steppers would work but add unnecessary complexity for this application. Servos provide 180° of rotation, which is exactly what we need.