DMX as enum

bluepill-rs/src/dmx.rs

@@ -1,46 +1,60 @@
-#![allow(unsafe_code)]
-
 use cortex_m::singleton;
-use stm32f1xx_hal::{afio, dma, gpio, pac, prelude::*, rcc, serial};
+use stm32f1xx_hal::{afio, dma, pac, prelude::*, rcc, serial};
 
-pub struct DMX {
-    tx: Option<dma::TxDma<serial::Tx<pac::USART1>, dma::dma1::C4>>,
+type _TxDma = dma::TxDma<serial::Tx<pac::USART1>, dma::dma1::C4>;
+
+pub struct DMXIdle {
+    tx: Option<_TxDma>,
     txbuffer: Option<&'static mut [u8; 512]>,
 }
 
+pub enum DMX {
+    Idle(DMXIdle),
+    Busy(Option<dma::Transfer<dma::R, &'static mut [u8; 512], _TxDma>>),
+}
+
 impl DMX {
-    pub fn new(
+    pub fn new<PINS>(
         usart: pac::USART1,
-        pins: (
-            gpio::Pin<'A', 9, gpio::Alternate<gpio::OpenDrain>>,
-            gpio::Pin<'A', 10>,
-        ),
+        pins: PINS,
         mapr: &mut afio::MAPR,
         channel: dma::dma1::C4,
         clocks: &rcc::Clocks,
-    ) -> Self {
+    ) -> Self
+    where
+        PINS: serial::Pins<pac::USART1>,
+    {
         // Serial config
         let serial = serial::Serial::new(usart, pins, mapr, 250_000.bps(), &clocks);
 
-        Self {
+        Self::Idle(DMXIdle {
             tx: Some(serial.tx.with_dma(channel)),
             txbuffer: None,
-        }
+        })
     }
 
     pub fn send(&mut self, data: &[u8; 512]) {
-        if let Some(mut tx) = self.tx.take() {
-            let mut txbuffer = match self.txbuffer.take() {
-                Some(buf) => buf,
-                None => singleton!(: [u8; 512] = [0; 512]).unwrap(),
-            };
+        if let Self::Idle(idle) = self {
+            let txbuffer = idle
+                .txbuffer
+                .take()
+                .unwrap_or_else(|| singleton!(: [u8; 512] = [0; 512]).unwrap());
+            let tx = idle.tx.take().unwrap();
 
             txbuffer.copy_from_slice(data);
-            let xfer = tx.write(txbuffer);
+            *self = Self::Busy(Some(tx.write(txbuffer)))
+        }
+    }
 
-            (txbuffer, tx) = xfer.wait();
-            self.tx.replace(tx);
-            self.txbuffer.replace(txbuffer);
+    pub fn wait(&mut self) {
+        if let Self::Busy(xfer) = self {
+            let xfer = xfer.take().unwrap();
+            let (txbuffer, tx) = xfer.wait();
+
+            *self = Self::Idle(DMXIdle {
+                tx: Some(tx),
+                txbuffer: Some(txbuffer),
+            });
         }
     }
 }

bluepill-rs/src/main.rs

@@ -100,6 +100,8 @@ mod app {
 
             cx.local.delay_us.delay(1.secs());
             cx.local.led.set_low();
+
+            cx.local.dmx.wait();
         }
     }
 }