Most models of Raspberry Pi are overpowered for many robotic projects but the Raspberry Pi Pico microcontroller and accompanying RP2040 chip really seem to fit the bill. Proving that case today is Chris Parrott who has developed his own Raspberry Pi RP2040 Robot PCB.
This palm-sized robot project is called Hex Mecanum. It features a six-sided design with wheels mounted to three of the sides. Parrott revealed in a Tweet this week pictures of the HexDriver board samples and again later with components soldered into place. Parrott's robot is a personal project, but in their day job at Pimoroni they have access to all of the latest products and we can see that robot is powered by the PGA2040 which breaks out the RP2040 into a smaller package than the Raspberry Pi Pico while providing all of the GPIO pins.
From what we've seen, some of the best Raspberry Pi projects use custom PCBs. This extra step takes time, as noted by Parrott who worked on this board design for months, but the end result is often worth the extra effort—even if just for the experience.
Another benefit of developing your own carrier board is getting creative with shapes and features. Parrott took advantage of the hexagonal space by fitting six meccanum wheels, powered by N20 50:1 geared motors with encoders used to accurately control the motor speed. All of the motors are controlled via DRV8833 motor controllers. We asked Parrott to elaborate on the robot's capabilities. "The board itself can drive 6 DC motors with encoders, or 3 Stepper motors, or 12 Servo motors, and supports 7x I2C sensors (for time of flight, IMU and such)"