update the embedded-hal dependency

Cargo.toml

@@ -18,7 +18,7 @@ version = "0.2.2"
 
 [dependencies.embedded-hal]
 git = "https://github.com/japaric/embedded-hal"
-rev = "5295697669f5b48a900aa325b8ebb4d4e8d4b236"
+rev = "7d904f515d15fd5fe7ea34e18820ea83e2651fa2"
 
 [dependencies.nb]
 git = "https://github.com/japaric/nb"

src/serial.rs

@@ -337,7 +337,7 @@ where
     }
 }
 
-impl<'a, U> hal::Serial for Serial<'a, U>
+impl<'a, U> hal::serial::Read<u8> for Serial<'a, U>
 where
     U: Any + Usart,
 {
@@ -363,6 +363,13 @@ where
             Err(nb::Error::WouldBlock)
         }
     }
+}
+
+impl<'a, U> hal::serial::Write<u8> for Serial<'a, U>
+where
+    U: Any + Usart,
+{
+    type Error = Error;
 
     fn write(&self, byte: u8) -> Result<()> {
         let usart1 = self.0;