Crate pdm

PDM

PDM (Pulse Density Modulator) is a library meant for digital-to-analog conversion in embedded systems, using a simple second-order delta sigma modulator. If no hardware PWM channels are available, this is a lightweight alternative.

This can be used, for example, to modulate the intensity of an LED.

Features

The library offers the following features:

• Easy to use
• Suitable for no_std environments
• No external dependencies
• Ultra-low RAM requirements
• Supports the following types: u8, u16, u32, u64, i8, i16, i32, i64, f32, f64

Limitations

For good results, the output frequency must be high and stable in relation to the modulated signal frequency. An external low-pass filter may be necessary to remove noise, depending on the application.

Example

let mut pdm = pdm::Pdm::<u8>::new();
pdm.set_value(42);
loop {
    if pdm.update() {
        // Set output high
    } else {
        // Set output low
    }
    // Sleep until next iteration
}

Changelog

Date	Version	Changes
2025-04-15	1.0.0	Cleaner code structure
2025-04-13	0.1.0	Initial release

Structs

Pdm

Pulse Density Modulator

Traits

Modulator

A trait that allow generic modulator implementations