diff --git a/embassy-nrf/src/chips/nrf52810.rs b/embassy-nrf/src/chips/nrf52810.rs
index faa52d8f..3e500098 100644
--- a/embassy-nrf/src/chips/nrf52810.rs
+++ b/embassy-nrf/src/chips/nrf52810.rs
@@ -128,6 +128,9 @@ embassy_hal_common::peripherals! {
// QDEC
QDEC,
+
+ // PDM
+ PDM,
}
impl_uarte!(UARTE0, UARTE0, UARTE0_UART0);
diff --git a/embassy-nrf/src/chips/nrf52811.rs b/embassy-nrf/src/chips/nrf52811.rs
index bbdf1cbe..25c7c0d9 100644
--- a/embassy-nrf/src/chips/nrf52811.rs
+++ b/embassy-nrf/src/chips/nrf52811.rs
@@ -128,6 +128,9 @@ embassy_hal_common::peripherals! {
// QDEC
QDEC,
+
+ // PDM
+ PDM,
}
impl_uarte!(UARTE0, UARTE0, UARTE0_UART0);
diff --git a/embassy-nrf/src/chips/nrf52832.rs b/embassy-nrf/src/chips/nrf52832.rs
index 18b8eda6..2c6276d4 100644
--- a/embassy-nrf/src/chips/nrf52832.rs
+++ b/embassy-nrf/src/chips/nrf52832.rs
@@ -138,6 +138,9 @@ embassy_hal_common::peripherals! {
// QDEC
QDEC,
+
+ // PDM
+ PDM,
}
impl_uarte!(UARTE0, UARTE0, UARTE0_UART0);
diff --git a/embassy-nrf/src/chips/nrf52833.rs b/embassy-nrf/src/chips/nrf52833.rs
index 39a0f93f..3b33907d 100644
--- a/embassy-nrf/src/chips/nrf52833.rs
+++ b/embassy-nrf/src/chips/nrf52833.rs
@@ -158,6 +158,9 @@ embassy_hal_common::peripherals! {
// QDEC
QDEC,
+
+ // PDM
+ PDM,
}
#[cfg(feature = "nightly")]
diff --git a/embassy-nrf/src/chips/nrf52840.rs b/embassy-nrf/src/chips/nrf52840.rs
index e3d8f34a..ae59f8b2 100644
--- a/embassy-nrf/src/chips/nrf52840.rs
+++ b/embassy-nrf/src/chips/nrf52840.rs
@@ -161,6 +161,9 @@ embassy_hal_common::peripherals! {
// TEMP
TEMP,
+
+ // PDM
+ PDM,
}
#[cfg(feature = "nightly")]
diff --git a/embassy-nrf/src/lib.rs b/embassy-nrf/src/lib.rs
index f3b3ca0c..20589195 100644
--- a/embassy-nrf/src/lib.rs
+++ b/embassy-nrf/src/lib.rs
@@ -103,6 +103,14 @@ pub mod uarte;
pub mod usb;
#[cfg(not(feature = "_nrf5340"))]
pub mod wdt;
+#[cfg(any(
+ feature = "nrf52810",
+ feature = "nrf52811",
+ feature = "nrf52832",
+ feature = "nrf52833",
+ feature = "nrf52840",
+))]
+pub mod pdm;
// This mod MUST go last, so that it sees all the `impl_foo!` macros
#[cfg_attr(feature = "nrf52805", path = "chips/nrf52805.rs")]
diff --git a/embassy-nrf/src/pdm.rs b/embassy-nrf/src/pdm.rs
new file mode 100644
index 00000000..629eab99
--- /dev/null
+++ b/embassy-nrf/src/pdm.rs
@@ -0,0 +1,185 @@
+#![macro_use]
+
+use core::sync::atomic::{compiler_fence, Ordering};
+use core::task::Poll;
+
+use embassy_hal_common::{into_ref, PeripheralRef};
+use embassy_util::waitqueue::AtomicWaker;
+use futures::future::poll_fn;
+use pac::{pdm, PDM};
+use pdm::mode::{EDGE_A, OPERATION_A};
+use fixed::types::I7F1;
+
+use crate::interrupt::InterruptExt;
+use crate::gpio::Pin as GpioPin;
+use crate::{interrupt, pac, peripherals, Peripheral};
+
+#[derive(Debug, Clone, Copy, PartialEq, Eq)]
+#[cfg_attr(feature = "defmt", derive(defmt::Format))]
+#[non_exhaustive]
+pub enum Error {}
+
+/// One-shot and continuous PDM.
+pub struct Pdm<'d> {
+ _p: PeripheralRef<'d, peripherals::PDM>,
+}
+
+static WAKER: AtomicWaker = AtomicWaker::new();
+
+/// Used to configure the PDM peripheral.
+///
+/// See the `Default` impl for suitable default values.
+#[non_exhaustive]
+pub struct Config {
+ /// Clock
+ /// Clock ratio
+ /// Channels
+ pub channels: Channels,
+ /// Edge to sample on
+ pub left_edge: Edge,
+ /// Gain left in dB
+ pub gain_left: I7F1,
+ /// Gain right in dB
+ pub gain_right: I7F1,
+}
+
+impl Default for Config {
+ /// Default configuration for single channel sampling.
+ fn default() -> Self {
+ Self {
+ channels: Channels::Stereo,
+ left_edge: Edge::FallingEdge,
+ gain_left: I7F1::ZERO,
+ gain_right: I7F1::ZERO,
+ }
+ }
+}
+
+/// The state of a continuously running sampler. While it reflects
+/// the progress of a sampler, it also signals what should be done
+/// next. For example, if the sampler has stopped then the Pdm implementation
+/// can then tear down its infrastructure.
+#[derive(PartialEq)]
+pub enum SamplerState {
+ Sampled,
+ Stopped,
+}
+
+impl<'d> Pdm<'d> {
+ pub fn new(
+ pdm: impl Peripheral + 'd,
+ irq: impl Peripheral
+ 'd,
+ data: impl Peripheral
+ 'd,
+ clock: impl Peripheral
+ 'd,
+ config: Config,
+ ) -> Self {
+ into_ref!(pdm, irq, data, clock);
+
+ let r = unsafe { &*PDM::ptr() };
+
+ let Config { channels, left_edge, gain_left, gain_right } = config;
+
+ // Configure channels
+ r.enable.write(|w| w.enable().enabled());
+ // TODO: Clock control
+ r.mode.write(|w| {
+ w.operation().variant(channels.into());
+ w.edge().variant(left_edge.into());
+ w
+ });
+
+ r.psel.din.write(|w| unsafe { w.bits(data.psel_bits()) });
+ r.psel.clk.write(|w| unsafe { w.bits(clock.psel_bits()) });
+
+ // Disable all events interrupts
+ r.intenclr.write(|w| unsafe { w.bits(0x003F_FFFF) });
+
+ irq.set_handler(Self::on_interrupt);
+ irq.unpend();
+ irq.enable();
+
+ Self { _p: pdm }
+ }
+
+ fn on_interrupt(_ctx: *mut ()) {
+ let r = Self::regs();
+
+ if r.events_end.read().bits() != 0 {
+ r.intenclr.write(|w| w.end().clear());
+ WAKER.wake();
+ }
+
+ if r.events_started.read().bits() != 0 {
+ r.intenclr.write(|w| w.started().clear());
+ WAKER.wake();
+ }
+ }
+
+ fn regs() -> &'static pdm::RegisterBlock {
+ unsafe { &*PDM::ptr() }
+ }
+
+ /// One shot sampling. If the PDM is configured for multiple channels, the samples will be interleaved.
+ pub async fn sample(&mut self, buf: &mut [i16; N]) {
+ let r = Self::regs();
+
+ // Set up the DMA
+ r.sample.ptr.write(|w| unsafe { w.sampleptr().bits(buf.as_mut_ptr() as u32) });
+ r.sample.maxcnt.write(|w| unsafe { w.buffsize().bits(N as _) });
+
+ // Reset and enable the end event
+ r.events_end.reset();
+ r.intenset.write(|w| w.end().set());
+
+ // Don't reorder the start event before the previous writes. Hopefully self
+ // wouldn't happen anyway.
+ compiler_fence(Ordering::SeqCst);
+
+ r.tasks_start.write(|w| { w.tasks_start().set_bit() });
+
+ // Wait for 'end' event.
+ poll_fn(|cx| {
+ let r = Self::regs();
+
+ WAKER.register(cx.waker());
+
+ if r.events_end.read().bits() != 0 {
+ r.events_end.reset();
+ return Poll::Ready(());
+ }
+
+ Poll::Pending
+ })
+ .await;
+ }
+}
+
+#[derive(Clone, Copy, PartialEq)]
+pub enum Edge {
+ FallingEdge,
+ RisingEdge,
+}
+
+impl From for EDGE_A {
+ fn from(edge: Edge) -> Self {
+ match edge {
+ Edge::FallingEdge => EDGE_A::LEFTFALLING,
+ Edge::RisingEdge => EDGE_A::LEFTRISING,
+ }
+ }
+}
+
+#[derive(Clone, Copy, PartialEq)]
+pub enum Channels {
+ Stereo,
+ Mono,
+}
+
+impl From for OPERATION_A {
+ fn from(ch: Channels) -> Self {
+ match ch {
+ Channels::Stereo => OPERATION_A::STEREO,
+ Channels::Mono => OPERATION_A::MONO,
+ }
+ }
+}
\ No newline at end of file
diff --git a/examples/nrf/Cargo.toml b/examples/nrf/Cargo.toml
index 2fcc3122..673bcfc6 100644
--- a/examples/nrf/Cargo.toml
+++ b/examples/nrf/Cargo.toml
@@ -27,6 +27,7 @@ cortex-m-rt = "0.7.0"
panic-probe = { version = "0.3", features = ["print-defmt"] }
futures = { version = "0.3.17", default-features = false, features = ["async-await"] }
rand = { version = "0.8.4", default-features = false }
+fixed = "1.10.0"
embedded-storage = "0.3.0"
usbd-hid = "0.5.2"
serde = { version = "1.0.136", default-features = false }
diff --git a/examples/nrf/src/bin/pdm.rs b/examples/nrf/src/bin/pdm.rs
new file mode 100644
index 00000000..d5e90e27
--- /dev/null
+++ b/examples/nrf/src/bin/pdm.rs
@@ -0,0 +1,34 @@
+#![no_std]
+#![no_main]
+#![feature(type_alias_impl_trait)]
+
+use defmt::info;
+use embassy_executor::Spawner;
+use embassy_nrf::interrupt;
+use embassy_nrf::pdm::{Config, Channels, Pdm};
+use embassy_time::{Duration, Timer};
+use fixed::types::I7F1;
+use {defmt_rtt as _, panic_probe as _};
+
+#[embassy_executor::main]
+async fn main(_p: Spawner) {
+ let mut p = embassy_nrf::init(Default::default());
+ let mut config = Config::default();
+ // Pins are correct for the onboard microphone on the Feather nRF52840 Sense.
+ config.channels = Channels::Mono;
+ config.gain_left = I7F1::from_bits(5); // 2.5 dB
+ let mut pdm = Pdm::new(p.PDM, interrupt::take!(PDM), &mut p.P0_00, &mut p.P0_01, config);
+
+ loop {
+ let mut buf = [0; 128];
+ pdm.sample(&mut buf).await;
+ info!(
+ "{} samples, min {=i16}, max {=i16}, mean {=i16}",
+ buf.len(),
+ buf.iter().min().unwrap(),
+ buf.iter().max().unwrap(),
+ (buf.iter().map(|v| i32::from(*v)).sum::() / buf.len() as i32) as i16,
+ );
+ Timer::after(Duration::from_millis(100)).await;
+ }
+}