+ 'd, + irq: impl Peripheral
+ 'd, + clk: impl Peripheral
+ 'd, + din: impl Peripheral
+ 'd, + config: Config, + ) -> Self { + into_ref!(clk, din); + Self::new_inner(pdm, irq, clk.map_into(), din.map_into(), config) + } + + fn new_inner( + _pdm: impl Peripheral
+ 'd, + irq: impl Peripheral
+ 'd, + clk: PeripheralRef<'d, AnyPin>, + din: PeripheralRef<'d, AnyPin>, + config: Config, + ) -> Self { + into_ref!(irq); + + let r = Self::regs(); + + // setup gpio pins + din.conf().write(|w| w.input().set_bit()); + r.psel.din.write(|w| unsafe { w.bits(din.psel_bits()) }); + clk.set_low(); + clk.conf().write(|w| w.dir().output()); + r.psel.clk.write(|w| unsafe { w.bits(clk.psel_bits()) }); + + // configure + // use default for + // - gain right + // - gain left + // - clk + // - ratio + r.mode.write(|w| { + w.edge().bit(config.edge == Edge::LeftRising); + w.operation().bit(config.operation_mode == OperationMode::Mono); + w + }); + r.gainl.write(|w| w.gainl().default_gain()); + r.gainr.write(|w| w.gainr().default_gain()); + + // IRQ + irq.disable(); + irq.set_handler(|_| { + let r = Self::regs(); + r.intenclr.write(|w| w.end().clear()); + WAKER.wake(); + }); + irq.enable(); + + r.enable.write(|w| w.enable().set_bit()); + + Self { + phantom: PhantomData, + irq, + } + } + + /// Start sampling microphon data into a dummy buffer + /// Usefull to start the microphon and keep it active between recording samples + pub async fn start(&mut self) { + let r = Self::regs(); + + // start dummy sampling because microphon needs some setup time + r.sample + .ptr + .write(|w| unsafe { w.sampleptr().bits(DUMMY_BUFFER.as_ptr() as u32) }); + r.sample + .maxcnt + .write(|w| unsafe { w.buffsize().bits(DUMMY_BUFFER.len() as _) }); + + r.tasks_start.write(|w| w.tasks_start().set_bit()); + } + + /// Stop sampling microphon data inta a dummy buffer + pub async fn stop(&mut self) { + let r = Self::regs(); + r.tasks_stop.write(|w| w.tasks_stop().set_bit()); + r.events_started.reset(); + } + + pub async fn sample(&mut self, buffer: &mut [i16]) -> Result<(), Error> { + if buffer.len() == 0 { + return Err(Error::BufferZeroLength); + } + if buffer.len() > EASY_DMA_SIZE { + return Err(Error::BufferTooLong); + } + + let r = Self::regs(); + + if r.events_started.read().events_started().bit_is_clear() { + return Err(Error::NotRunning); + } + + let drop = OnDrop::new(move || { + r.intenclr.write(|w| w.end().clear()); + r.events_stopped.reset(); + + // reset to dummy buffer + r.sample + .ptr + .write(|w| unsafe { w.sampleptr().bits(DUMMY_BUFFER.as_ptr() as u32) }); + r.sample + .maxcnt + .write(|w| unsafe { w.buffsize().bits(DUMMY_BUFFER.len() as _) }); + + while r.events_stopped.read().bits() == 0 {} + }); + + // setup user buffer + let ptr = buffer.as_ptr(); + let len = buffer.len(); + r.sample.ptr.write(|w| unsafe { w.sampleptr().bits(ptr as u32) }); + r.sample.maxcnt.write(|w| unsafe { w.buffsize().bits(len as _) }); + + // wait till the current sample is finished and the user buffer sample is started + Self::wait_for_sample().await; + + // reset the buffer back to the dummy buffer + r.sample + .ptr + .write(|w| unsafe { w.sampleptr().bits(DUMMY_BUFFER.as_ptr() as u32) }); + r.sample + .maxcnt + .write(|w| unsafe { w.buffsize().bits(DUMMY_BUFFER.len() as _) }); + + // wait till the user buffer is sampled + Self::wait_for_sample().await; + + drop.defuse(); + + Ok(()) + } + + async fn wait_for_sample() { + let r = Self::regs(); + + r.events_end.reset(); + r.intenset.write(|w| w.end().set()); + + compiler_fence(Ordering::SeqCst); + + poll_fn(|cx| { + WAKER.register(cx.waker()); + if r.events_end.read().events_end().bit_is_set() { + return Poll::Ready(()); + } + Poll::Pending + }) + .await; + + compiler_fence(Ordering::SeqCst); + } + + fn regs() -> &'static pac::pdm::RegisterBlock { + unsafe { &*pac::PDM::ptr() } + } +} + +/// PDM microphone driver Config +pub struct Config { + /// Use stero or mono operation + pub operation_mode: OperationMode, + /// On which edge the left channel should be samples + pub edge: Edge, +} + +impl Default for Config { + fn default() -> Self { + Self { + operation_mode: OperationMode::Mono, + edge: Edge::LeftFalling, + } + } +} + +#[derive(PartialEq)] +pub enum OperationMode { + Mono, + Stereo, +} +#[derive(PartialEq)] +pub enum Edge { + LeftRising, + LeftFalling, +} + +impl<'d> Drop for Pdm<'d> { + fn drop(&mut self) { + let r = Self::regs(); + + r.tasks_stop.write(|w| w.tasks_stop().set_bit()); + + self.irq.disable(); + + r.enable.write(|w| w.enable().disabled()); + + r.psel.din.reset(); + r.psel.clk.reset(); + } +} diff --git a/examples/nrf/src/bin/pdm.rs b/examples/nrf/src/bin/pdm.rs new file mode 100644 index 00000000..7388580f --- /dev/null +++ b/examples/nrf/src/bin/pdm.rs @@ -0,0 +1,33 @@ +#![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, Pdm}; +use embassy_time::{Duration, Timer}; +use {defmt_rtt as _, panic_probe as _}; + +#[embassy_executor::main] +async fn main(_p: Spawner) { + let p = embassy_nrf::init(Default::default()); + let config = Config::default(); + let mut pdm = Pdm::new(p.PDM, interrupt::take!(PDM), p.P0_01, p.P0_00, config); + + loop { + pdm.start().await; + + // wait some time till the microphon settled + Timer::after(Duration::from_millis(1000)).await; + + const SAMPLES: usize = 2048; + let mut buf = [0i16; SAMPLES]; + pdm.sample(&mut buf).await.unwrap(); + + info!("samples: {:?}", &buf); + + pdm.stop().await; + Timer::after(Duration::from_millis(100)).await; + } +}