Micropython PWM

Micropython PWM

The video titled “Micropython PWM” explains the concept and practical use of Pulse Width Modulation (PWM) in MicroPython, particularly on the Raspberry Pi Pico microcontroller.

Key Technological Concepts

Analog Input vs. Analog Output

The video starts by contrasting analog input (measuring voltage and mapping it to digital values) with analog output, which is more complex and often requires expensive hardware like Digital-to-Analog Converters (DACs). The Raspberry Pi Pico does not have a DAC, but PWM offers a workaround.

Pulse Width Modulation (PWM)

PWM is a technique to simulate analog output by rapidly toggling a digital output pin on and off. By adjusting the proportion of time the signal is “on” (duty cycle), it creates the perception of varying voltage levels.

• Duty Cycle: Percentage of time the signal is high during one cycle (0% = always off, 100% = always on).
• Frequency: How fast the signal toggles on and off (cycles per second). High frequency results in smoother analog perception.

Applications of PWM

• Controlling LED brightness by adjusting duty cycle.
• Motor speed control and fan speed regulation.
• Servo motor positioning (communication via PWM signals).
• Generating waveforms and sound signals.

Product Features & Practical Guide

The video demonstrates how to implement PWM in MicroPython on the Raspberry Pi Pico using the machine library.

The code walkthrough includes:

• Importing PWM from the machine module.
• Creating a PWM object on a specific pin (e.g., pin 0) with a set frequency (e.g., 2000 Hz).
• Controlling the LED brightness by setting the duty cycle proportional to user input (percentage brightness).
• Handling user input safely with try-except blocks to validate input and convert it to an integer duty cycle value.

The code example maps user input percentage (0-100%) to a duty cycle value between 0 and 65535 (the max PWM resolution on Pico).

Summary of Tutorial Steps

1. Explanation of PWM concepts (frequency, duty cycle).
2. Visual examples of PWM signals at different duty cycles.
3. Coding a PWM example in MicroPython to control LED brightness interactively.
4. Error handling for input conversion.
5. Testing various brightness levels through user input.

Main Speaker / Source

The video appears to be presented by a technical instructor or hobbyist familiar with MicroPython and Raspberry Pi Pico, providing a step-by-step educational tutorial on PWM fundamentals and coding.

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This summary highlights the educational focus on PWM technology, its applications, and a practical MicroPython coding guide for beginners or hobbyists working with the Raspberry Pi Pico.