From 340c5c3fb26691249c03de9ef41304510f4fb6c6 Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?J=C3=B6rn-Michael?=
 <40151420+ldericher@users.noreply.github.com>
Date: Thu, 21 Mar 2024 14:29:37 +0000
Subject: [PATCH] create dmx.rs

---
 bluepill-rs/src/dmx.rs  | 46 +++++++++++++++++++++++++++++++++++++++++
 bluepill-rs/src/main.rs | 35 +++++++++++++------------------
 2 files changed, 60 insertions(+), 21 deletions(-)
 create mode 100644 bluepill-rs/src/dmx.rs

diff --git a/bluepill-rs/src/dmx.rs b/bluepill-rs/src/dmx.rs
new file mode 100644
index 0000000..b1112ce
--- /dev/null
+++ b/bluepill-rs/src/dmx.rs
@@ -0,0 +1,46 @@
+#![allow(unsafe_code)]
+
+use cortex_m::singleton;
+use stm32f1xx_hal::{afio, dma, gpio, pac, prelude::*, rcc, serial};
+
+pub struct DMX {
+    tx: Option<dma::TxDma<serial::Tx<pac::USART1>, dma::dma1::C4>>,
+    txbuffer: Option<&'static mut [u8; 512]>,
+}
+
+impl DMX {
+    pub fn new(
+        usart: pac::USART1,
+        pins: (
+            gpio::Pin<'A', 9, gpio::Alternate<gpio::OpenDrain>>,
+            gpio::Pin<'A', 10>,
+        ),
+        mapr: &mut afio::MAPR,
+        channel: dma::dma1::C4,
+        clocks: &rcc::Clocks,
+    ) -> Self {
+        // Serial config
+        let serial = serial::Serial::new(usart, pins, mapr, 250_000.bps(), &clocks);
+
+        Self {
+            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(),
+            };
+
+            txbuffer.copy_from_slice(data);
+            let xfer = tx.write(txbuffer);
+
+            (txbuffer, tx) = xfer.wait();
+            self.tx.replace(tx);
+            self.txbuffer.replace(txbuffer);
+        }
+    }
+}
diff --git a/bluepill-rs/src/main.rs b/bluepill-rs/src/main.rs
index 333c3db..b15891b 100644
--- a/bluepill-rs/src/main.rs
+++ b/bluepill-rs/src/main.rs
@@ -2,18 +2,21 @@
 #![no_std]
 #![no_main]
 
-mod i2c_reg_slave;
-mod i2c_slave;
+// mod i2c_reg_slave;
+// mod i2c_slave;
+mod dmx;
 
 // extern crate panic_halt;
 extern crate panic_semihosting;
 
-#[rtic::app(device = stm32f1xx_hal::pac)]
+#[rtic::app(device = stm32f1xx_hal::pac, dispatchers = [DMA1_CHANNEL4])]
 mod app {
     use cortex_m::singleton;
-    use stm32f1xx_hal::{dma, gpio, pac, prelude::*, serial, timer};
+    use stm32f1xx_hal::{gpio, pac, prelude::*, timer};
     use systick_monotonic::Systick;
 
+    use crate::dmx::DMX;
+
     // A monotonic timer to enable scheduling in RTIC
     #[monotonic(binds = SysTick, default = true)]
     type MyMono = Systick<100>; // 100 Hz / 10 ms granularity
@@ -25,8 +28,7 @@ mod app {
 
     #[local]
     struct Local {
-        tx: Option<dma::TxDma<serial::Tx<pac::USART1>, dma::dma1::C4>>,
-        txbuffer: Option<&'static mut [u8; 512]>,
+        dmx: DMX,
         delay_us: timer::DelayUs<pac::TIM2>,
         led: gpio::gpioc::PC13<gpio::Output>,
     }
@@ -59,14 +61,14 @@ mod app {
         let dma1 = cx.device.DMA1.split();
 
         // Serial config
-        let serial = serial::Serial::new(
+        let dmx = DMX::new(
             cx.device.USART1,
             (
-                gpioa.pa9.into_alternate_push_pull(&mut gpioa.crh),
+                gpioa.pa9.into_alternate_open_drain(&mut gpioa.crh),
                 gpioa.pa10, //.into_pull_up_input(&mut gpioa.crh),
             ),
             &mut afio.mapr,
-            250_000.bps(),
+            dma1.4,
             &clocks,
         );
 
@@ -75,8 +77,7 @@ mod app {
                 buffer: singleton!(: [u8; 512] = [0b01010101; 512]).unwrap(),
             },
             Local {
-                tx: Some(serial.tx.with_dma(dma1.4)),
-                txbuffer: Some(singleton!(: [u8; 512] = [0; 512]).unwrap()),
+                dmx: dmx,
 
                 // Configure timer
                 delay_us: cx.device.TIM2.delay_us(&clocks),
@@ -89,24 +90,16 @@ mod app {
         )
     }
 
-    #[idle(local = [tx, txbuffer, delay_us, led], shared = [&buffer])]
+    #[idle(local = [dmx, delay_us, led], shared = [&buffer])]
     fn idle(cx: idle::Context) -> ! {
         loop {
-            let mut tx = cx.local.tx.take().unwrap();
-            let mut txbuffer = cx.local.txbuffer.take().unwrap();
-
-            txbuffer.copy_from_slice(*cx.shared.buffer);
-            let xfer = tx.write(txbuffer);
+            cx.local.dmx.send(cx.shared.buffer);
 
             cx.local.delay_us.delay(1.secs());
             cx.local.led.set_high();
 
             cx.local.delay_us.delay(1.secs());
             cx.local.led.set_low();
-
-            (txbuffer, tx) = xfer.wait();
-            cx.local.tx.replace(tx);
-            cx.local.txbuffer.replace(txbuffer);
         }
     }
 }