The 3pi+ 2040 is a versatile, high-performance, user-programmable robot that measures just 9.7 cm (3.8″) in diameter. At its heart is a Raspberry Pi RP2040 microcontroller (like the one on the Raspberry Pi Pico), a 32-bit dual-core Arm Cortex-M0+ processor running at 125 MHz, which can be programmed with C, C++, Arduino, or Python. The 3pi+ 2040 has 16 MB (128 Mbit) of flash memory that ships preloaded with a MicroPython interpreter, so you can get started right away by plugging into its USB C port and editing the included example Python programs. For advanced users who want to customize or enhance their robots with additional peripherals, the robot’s power rails, power system controls, and microcontroller’s I/O lines can be accessed via several 0.1″-pitch expansion ports.
 | 3pi+ 2040 Robot, front view. |
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 | 3pi+ 2040 Robot, side view. |
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 | 3pi+ 2040 Robot, rear view. |
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The 3pi+ (or 3𝜋+) 2040 features two H-bridge motor drivers and a variety of integrated sensors, including a pair of quadrature encoders for closed-loop motor control, a complete inertial measurement unit (3-axis accelerometer, gyro, and magnetometer), five downward-facing reflectance sensors for line-following or edge-detection, and left and right bump sensors along the front face of the robot. Three on-board pushbuttons offer a convenient interface for user input, and a 128×64 graphical OLED display, buzzer, and six RGB LEDs allow the robot to provide feedback.
The robot also features a unique power system that runs the motors at a constant 8 V independent of the battery charge level, so the speed of the motors does not vary with the battery voltage.
