From 08229bc0e9e1d37cfa9aac9082f63dcf432418fc Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?J=C3=B6rn-Michael?=
 <40151420+ldericher@users.noreply.github.com>
Date: Fri, 1 Mar 2024 15:18:26 +0000
Subject: [PATCH] repeated dma send

---
 src/main.rs | 22 +++++++---------------
 1 file changed, 7 insertions(+), 15 deletions(-)

diff --git a/src/main.rs b/src/main.rs
index 1b33e23..a82cce7 100644
--- a/src/main.rs
+++ b/src/main.rs
@@ -46,7 +46,7 @@ fn main() -> ! {
         &mut flash.acr,
     );
 
-    // Acquire the GPIOC peripheral
+    // Acquire the peripherals
     let mut gpioa = dp.GPIOA.split();
     let mut gpioc = dp.GPIOC.split();
 
@@ -62,20 +62,14 @@ fn main() -> ! {
         (tx, rx),
         &mut afio.mapr,
         serial::Config {
-            baudrate: 9_600.bps(),
+            baudrate: 250_000.bps(),
             ..Default::default()
         },
         &clocks,
     );
 
-    let tx = serial.tx.with_dma(dma1.4);
-    let buf = singleton!(: [u8; 255] = [0b01010101; 255]).unwrap();
-
-    let xfer = tx.write(buf);
-    while !xfer.is_done() {}
-
-    // while circ_buffer.readable_half().unwrap() != dma::Half::First {}
-    // let _first_half = circ_buffer.peek(|half, _| *half).unwrap();
+    let mut tx = serial.tx.with_dma(dma1.4);
+    let mut buf = singleton!(: [u8; 255] = [0b01010101; 255]).unwrap();
 
     // Configure gpio C pin 13 as a push-pull output. The `crh` register is passed to the function
     // in order to configure the port. For pins 0-7, crl should be passed instead.
@@ -86,13 +80,9 @@ fn main() -> ! {
     // at 72 MHz, timer of 1 Hz overflows, use 10 Hz instead (8 Hz experimental minimum)
     timer.start(10.Hz()).unwrap();
 
-    // equivalent timers:
-    // let mut timer = Timer::syst(cp.SYST, &clocks).counter_us(); // us resolution
-    // let mut timer: SysCounter<1000> = Timer::syst(cp.SYST, &clocks).counter(); // ms resolution
-    // timer.start(100.millis()).unwrap();
-
     // Wait for the timer to trigger an update and change the state of the LED
     loop {
+        let xfer = tx.write(buf);
         for _ in 0..10 {
             block!(timer.wait()).unwrap();
         }
@@ -102,5 +92,7 @@ fn main() -> ! {
             block!(timer.wait()).unwrap();
         }
         led.set_low();
+
+        (buf, tx) = xfer.wait();
     }
 }