Increase serial rate to 38400 baud

src/main.rs

@@ -132,7 +132,7 @@ fn main() -> ! {
     );
     let uart = hal::uart::UartPeripheral::new(pac.UART0, uart_pins, &mut pac.RESETS)
         .enable(
-            UartConfig::new(9600.Hz(), DataBits::Eight, None, StopBits::One),
+            UartConfig::new(38400.Hz(), DataBits::Eight, None, StopBits::One),
             clocks.peripheral_clock.freq(),
         )
         .unwrap();