Merge pull request #209 from kalkyl/i2s-dma

Use DMA Transfer API in I2S module

Author: jonas-schievink

examples/i2s-controller-demo/src/main.rs

@@ -32,11 +32,8 @@ use {
 #[rtic::app(device = crate::hal::pac, peripherals = true, monotonic = rtic::cyccnt::CYCCNT)]
 const APP: () = {
     struct Resources {
-        i2s: hal::i2s::I2S,
-        #[init([0; 32])]
-        signal_buf: [i16; 32],
-        #[init([0; 32])]
-        mute_buf: [i16; 32],
+        signal_buf: &'static [i16],
+        mute_buf: &'static [i16],
         #[init(None)]
         queue: Option<Queue<State, U256>>,
         producer: Producer<'static, State, U256>,
@@ -49,10 +46,21 @@ const APP: () = {
         btn1: Pin<Input<PullUp>>,
         btn2: Pin<Input<PullUp>>,
         led: Pin<Output<PushPull>>,
+        transfer: Option<Transfer<&'static [i16]>>,
     }
 
-    #[init(resources = [queue, signal_buf, mute_buf], spawn = [tick])]
+    #[init(resources = [queue], spawn = [tick])]
     fn init(mut ctx: init::Context) -> init::LateResources {
+        static mut MUTE_BUF: [i16; 32] = [0i16; 32];
+        static mut SIGNAL_BUF: [i16; 32] = [0i16; 32];
+
+        // Fill signal buffer with triangle waveform, 2 channels interleaved
+        let len = SIGNAL_BUF.len() / 2;
+        for x in 0..len {
+            SIGNAL_BUF[2 * x] = triangle_wave(x as i32, len, 2048, 0, 1) as i16;
+            SIGNAL_BUF[2 * x + 1] = triangle_wave(x as i32, len, 2048, 0, 1) as i16;
+        }
+
         let _clocks = hal::clocks::Clocks::new(ctx.device.CLOCK).enable_ext_hfosc();
         // Enable the monotonic timer (CYCCNT)
         ctx.core.DCB.enable_trace();
@@ -75,16 +83,7 @@ const APP: () = {
             None,
             Some(&sdout_pin),
         );
-        i2s.tx_buffer(&ctx.resources.mute_buf[..]).ok();
-        i2s.enable().start();
-
-        // Fill signal buffer with triangle waveform, 2 channels interleaved
-        let signal_buf = ctx.resources.signal_buf;
-        let len = signal_buf.len() / 2;
-        for x in 0..len {
-            signal_buf[2 * x] = triangle_wave(x as i32, len, 2048, 0, 1) as i16;
-            signal_buf[2 * x + 1] = triangle_wave(x as i32, len, 2048, 0, 1) as i16;
-        }
+        i2s.start();
 
         // Configure buttons
         let btn1 = p0.p0_11.into_pullup_input().degrade();
@@ -117,7 +116,6 @@ const APP: () = {
         ctx.spawn.tick().ok();
 
         init::LateResources {
-            i2s,
             producer,
             consumer,
             gpiote,
@@ -126,6 +124,9 @@ const APP: () = {
             led: p0.p0_13.into_push_pull_output(Level::High).degrade(),
             uarte,
             uarte_timer: Timer::new(ctx.device.TIMER0),
+            transfer: i2s.tx(&MUTE_BUF[..]).ok(),
+            signal_buf: &SIGNAL_BUF[..],
+            mute_buf: &MUTE_BUF[..],
         }
     }
 
@@ -150,7 +151,7 @@ const APP: () = {
                     }
                 }
                 Err(hal::uarte::Error::Timeout(n)) if n > 0 => {
-                    if let Ok(msg) = core::str::from_utf8(&uarte_rx_buf[0..n]) {
+                    if let Ok(msg) = core::str::from_utf8(&uarte_rx_buf[..n]) {
                         rprintln!("{}", msg);
                         for action in encode(msg) {
                             for _ in 0..action.duration {
@@ -164,18 +165,18 @@ const APP: () = {
         }
     }
 
-    #[task(resources = [consumer, i2s, signal_buf, mute_buf, led, speed], schedule = [tick])]
+    #[task(resources = [consumer, transfer, signal_buf, mute_buf, led, speed], schedule = [tick])]
     fn tick(ctx: tick::Context) {
-        let i2s = ctx.resources.i2s;
+        let (_buf, i2s) = ctx.resources.transfer.take().unwrap().wait();
         match ctx.resources.consumer.dequeue() {
             Some(State::On) => {
                 // Move TX pointer to signal buffer (sound ON)
-                i2s.tx_buffer(&ctx.resources.signal_buf[..]).ok();
+                *ctx.resources.transfer = i2s.tx(*ctx.resources.signal_buf).ok();
                 ctx.resources.led.set_low().ok();
             }
             _ => {
                 // Move TX pointer to silent buffer (sound OFF)
-                i2s.tx_buffer(&ctx.resources.mute_buf[..]).ok();
+                *ctx.resources.transfer = i2s.tx(*ctx.resources.mute_buf).ok();
                 ctx.resources.led.set_high().ok();
             }
         }
@@ -190,7 +191,7 @@ const APP: () = {
         ctx.schedule.debounce(ctx.start + 3_000_000.cycles()).ok();
     }
 
-    #[task(resources = [btn1, btn2, i2s, speed])]
+    #[task(resources = [btn1, btn2, speed])]
     fn debounce(ctx: debounce::Context) {
         if ctx.resources.btn1.is_low().unwrap() {
             rprintln!("Go slower");

examples/i2s-peripheral-demo/Cargo.toml

@@ -12,8 +12,6 @@ cortex-m = "0.6.2"
 cortex-m-rtic = "0.5.3"
 rtt-target = {version = "0.2.0", features = ["cortex-m"] }
 nrf52840-hal = { features = ["rt"], path = "../../nrf52840-hal" }
-small_morse = "0.1.0"
-m = "0.1.1"
 
 [dependencies.embedded-hal]
 version = "0.2.3"

examples/i2s-peripheral-demo/src/main.rs

@@ -2,10 +2,9 @@
 #![no_main]
 
 // I2S `peripheral mode` demo
-// RMS level indicator using an RGB LED (APA102 on ItsyBitsy nRF52840)
+// Signal average level indicator using an RGB LED (APA102 on ItsyBitsy nRF52840)
 
 use embedded_hal::blocking::spi::Write;
-use m::Float;
 use {
     core::{
         panic::PanicInfo,
@@ -29,14 +28,14 @@ const RED: [u8; 9] = [0x00, 0x00, 0x00, 0x00, 0xFF, 0x00, 0x00, 0x10, 0xFF];
 #[rtic::app(device = crate::hal::pac, peripherals = true)]
 const APP: () = {
     struct Resources {
-        i2s: I2S,
-        #[init([0; 128])]
-        rx_buf: [i16; 128],
         rgb: Spim<SPIM0>,
+        transfer: Option<Transfer<&'static mut [i16; 128]>>,
     }
 
-    #[init(resources = [rx_buf])]
+    #[init]
     fn init(ctx: init::Context) -> init::LateResources {
+        static mut RX_BUF: [i16; 128] = [0; 128];
+
         let _clocks = hal::clocks::Clocks::new(ctx.device.CLOCK).enable_ext_hfosc();
         rtt_init_print!();
         rprintln!("Play me some audio...");
@@ -56,10 +55,7 @@ const APP: () = {
             Some(&sdin_pin),
             None,
         );
-        i2s.enable_interrupt(I2SEvent::RxPtrUpdated)
-            .rx_buffer(&mut ctx.resources.rx_buf[..])
-            .ok();
-        i2s.enable().start();
+        i2s.enable_interrupt(I2SEvent::RxPtrUpdated).start();
 
         // Configure APA102 RGB LED control
         let p1 = hal::gpio::p1::Parts::new(ctx.device.P1);
@@ -80,28 +76,29 @@ const APP: () = {
             },
             0,
         );
-
-        init::LateResources { i2s, rgb }
+        init::LateResources {
+            rgb,
+            transfer: i2s.rx(RX_BUF).ok(),
+        }
     }
 
-    #[task(binds = I2S, resources = [i2s, rx_buf, rgb])]
+    #[task(binds = I2S, resources = [rgb, transfer])]
     fn on_i2s(ctx: on_i2s::Context) {
-        let on_i2s::Resources { i2s, rx_buf, rgb } = ctx.resources;
+        let (rx_buf, i2s) = ctx.resources.transfer.take().unwrap().wait();
         if i2s.is_event_triggered(I2SEvent::RxPtrUpdated) {
             i2s.reset_event(I2SEvent::RxPtrUpdated);
-            // Calculate mono summed RMS of received buffer
-            let rms = Float::sqrt(
-                (rx_buf.iter().map(|x| *x as i32).map(|x| x * x).sum::<i32>() / rx_buf.len() as i32)
-                    as f32,
-            ) as u16;
-            let color = match rms {
+            //Calculate mono summed average of received buffer
+            let avg = (rx_buf.iter().map(|x| (*x).abs() as u32).sum::<u32>() / rx_buf.len() as u32)
+                as u16;
+            let color = match avg {
                 0..=4 => &OFF,
                 5..=10_337 => &GREEN,
                 10_338..=16_383 => &ORANGE,
                 _ => &RED,
             };
-            <Spim<SPIM0> as Write<u8>>::write(rgb, color).ok();
+            <Spim<SPIM0> as Write<u8>>::write(ctx.resources.rgb, color).ok();
         }
+        *ctx.resources.transfer = i2s.rx(rx_buf).ok();
     }
 };
 

nrf-hal-common/Cargo.toml

@@ -24,6 +24,7 @@ nb = "1.0.0"
 fixed = "1.0.0"
 rand_core = "0.5.1"
 cfg-if = "0.1.10"
+embedded-dma = "0.1.1"
 
 [dependencies.void]
 default-features = false