Wiring Diagrams

Breadboard Experiment with Pico, ESC and Servo

For electronics beginners, we highly recommend to set up the circuit on a breadboard following the diagram below.

Note: this is just the signal paths.

breadboard_pico_esc_servo

Drivetrain Wiring

Connect the battery to ESC, so that the Pico board can order it (ESC) to squeeze some juice and spin the motors.

drivetrain_electric

Explain the Drivetrain

  • The ESC (Electronic Speed Controller) governs the main engine motor's speed. And thus, it determines how fast the BearCar can go.
  • The servo motor (underneath ESC) has a position feedback circuit built-in. Hence, it determines the steering angle of the BearCar.
  • The Quicrun 1060 Brushed ESC has a BEC (Battery Elimination Circuit). It is capable of outputting 6V 3A electric energy. It is used to power the steering servo, and thus eliminates the need for another battery.
  • Neither Raspberry Pi 5 nor the Pico board is powerful enough to directly drive the motors (especially the main engine). So, a battery pack like a LiPO battery is needed to satisfy the energy hungry motors.
  • The Pico board uses 50Hz PWM (Pulse Width Modulation) signal to tell ESC how fast the main engine should run.

esc_motor_pwm

  • The Pico board also uses 50Hz PWM signal to tell servo what angle it should spin to.

servo_pwm