diff --git a/examples/ch32v307/src/bin/adc.rs b/examples/ch32v307/src/bin/adc.rs
index 43faaf2..442be29 100644
--- a/examples/ch32v307/src/bin/adc.rs
+++ b/examples/ch32v307/src/bin/adc.rs
@@ -17,7 +17,7 @@ async fn main(spawner: Spawner) -> ! {
     let p = hal::init(config);
     hal::embassy::init();
 
-    let mut delay = Delay;
+    let delay = Delay;
 
     let mut adc = hal::adc::Adc::new(p.ADC1, Default::default());
 
diff --git a/examples/ch32v307/src/bin/rcc.rs b/examples/ch32v307/src/bin/rcc.rs
index 2645ccd..7385042 100644
--- a/examples/ch32v307/src/bin/rcc.rs
+++ b/examples/ch32v307/src/bin/rcc.rs
@@ -23,9 +23,9 @@ async fn blink(pin: AnyPin, interval_ms: u64) {
 #[embassy_executor::main(entry = "qingke_rt::entry")]
 async fn main(spawner: Spawner) -> ! {
     hal::debug::SDIPrint::enable();
-    let config = hal::Config {
-        rcc: hal::rcc::Config::SYSCLK_FREQ_144MHZ_HSE,
-    };
+    let mut config = hal::Config::default();
+    config.rcc = hal::rcc::Config::SYSCLK_FREQ_144MHZ_HSE;
+
     let p = hal::init(config);
     hal::embassy::init();
 
diff --git a/examples/ch32v307/src/bin/uart.rs b/examples/ch32v307/src/bin/uart.rs
index 27e062e..7d574a0 100644
--- a/examples/ch32v307/src/bin/uart.rs
+++ b/examples/ch32v307/src/bin/uart.rs
@@ -30,7 +30,7 @@ async fn main(spawner: Spawner) -> ! {
     spawner.spawn(blink(p.PA0.degrade())).unwrap();
 
     let mut cfg = usart::Config::default();
-    let mut uart = UartTx::new(p.USART1, p.PA9, cfg).unwrap();
+    let mut uart = UartTx::new_blocking(p.USART1, p.PA9, cfg).unwrap();
 
     loop {
         Timer::after_millis(2000).await;
diff --git a/examples/ch32v307/src/bin/uart_echo.rs b/examples/ch32v307/src/bin/uart_echo.rs
index eff74e8..6512e1c 100644
--- a/examples/ch32v307/src/bin/uart_echo.rs
+++ b/examples/ch32v307/src/bin/uart_echo.rs
@@ -20,23 +20,24 @@ async fn main(spawner: Spawner) -> ! {
 
     let mut cfg = usart::Config::default();
     //cfg.baudrate = 1000000;
-    let mut uart = Uart::new(p.USART1, p.PA9, p.PA10, cfg).unwrap();
+    let mut uart = Uart::new_blocking(p.USART1, p.PA10, p.PA9, cfg).unwrap();
 
     uart.blocking_write(b"Init ok\r\n");
 
+    // FIXME: no time slice for embassy executor
+    let mut buf = [0u8; 1];
     loop {
-        // Timer::after_millis(2000).await;
-        while let Ok(b) = nb::block!(uart.nb_read()) {
-            if b == b'\r' {
-                uart.blocking_write(b"\r\n");
-            } else {
-                uart.blocking_write(&[b]);
-            }
-        }
+        uart.blocking_read(&mut buf).unwrap();
 
-        led.toggle();
+        if buf[0] >= b'a' && buf[0] <= b'z' {
+            buf[0] -= 32;
+        }
 
-        //uart.blocking_write(b"Hello from serial\r\n");
-        // println!("fuck");
+        if buf[0] == b'\r' {
+            uart.blocking_write(b"\r\n").unwrap();
+            led.toggle();
+        } else {
+            uart.blocking_write(&buf).unwrap();
+        }
     }
 }