Overview#

Figure 19 shows the main components of the robot hardware. A Raspberry PI 4 provides compute power, wireless connectivity, and a camera interface. To aid development, it runs ide49.

An STM32 microcontroller interfaces with the motors. The encoders measure the actual speed of the motors. The IMU detects the orientation of the robot.

The motors and electronics are powered from a 12V Lithium battery. An on-board switching regulators generates the 5V supply for the Raspberry PI.

The remote controller communicates over BLE with the Raspberry PI, which forwards commands to the STM32.

../../_images/robot.png

Fig. 19 Main components of the robot.#

All the “custom” electronics is combined on a small PCB in the form of a Raspberry PI “hat”. Figure 20 shows the schematic diagram.

../../_images/motor_hat.png

Fig. 20 Motor-hat circuit diagram (pdf)#

Motor & encoder connections:

Screw Terminal

Motor

AO1 drive

black 1

AO2 drive

red 1

BO1 drive

black 2

BO2 drive

red 2

3.3V

blue 1

GND

green 1

ENC_B1

white 1

ENC_B2

yellow 1

ENC_A1

white 2

ENC_A2

yellow 2

GND

green 2

3.3V

blue 2