An Introduction to the Raspberry Pi Pico with MicroPython

The Raspberry Pi Pico was recently released by the Raspberry Pi Foundation as a competitive microcontroller in the open-source electronics sphere. The Pico shares many of the capabilities of common Arduino boards including: analog-to-digital conversion (12-bit ADC), UART, SPI, I2C, PWM, among others. The board is just 21mm x 51mm in size, making it ideal for applications that require low-profile designs. One of the innovations of the Pico is the dual-core processor, which permits multiprocessing at clock rates up to 133 MHz. One particular draw of the Pico is its compatibility with MicroPython, which is chosen as the programming tool for this project. The focus on MicroPython, as opposed to C/C++, minimizes the confusion and time required to get started with the Pico. A Raspberry Pi 4 computer is ideal for interfacing with the Pico, which can be used to prepare, debug, and program the Pico. From start to finish - this tutorial helps users run their first custom MicroPython script on the Pico in just a few minutes. An RGB LED will be used to demonstrate general purpose input/output of the Pico microcontroller.

Raspberry Pi Stepper Motor Control with NEMA 17

The NEMA 17 is a widely used class of stepper motor used in 3D printers, CNC machines, linear actuators, and other precision engineering applications where accuracy and stability are essential. The NEMA-17HS4023 is introduced here, which is a version of the NEMA 17 that has dimensions 42mm x 42mm x 23mm (Length x Width x Height). In this tutorial, the stepper motor is controlled by a DRV8825 driver wired to a Raspberry Pi 4 computer. The Raspberry Pi uses Python to control the motor using an open-source motor library. The wiring and interfacing between the NEMA 17 and Raspberry Pi is given, with an emphasis on the basics of stepper motors. The DRV8825 control parameters in the Python stepper library are broken down to educate users on how the varying of each parameter impacts the behavior of the NEMA 17. Simple characteristics of stepper control are explored: stepper directivity (clockwise and counterclockwise), step incrementing (full step, half step, micro-stepping, etc.), and step delay.