Implemented frame transfer for four-wire bus

src/bus/four_wire.rs

@@ -1,3 +1,4 @@
+use byteorder::{BigEndian, ByteOrder};
 use embedded_hal::digital::v2::OutputPin;
 use embedded_hal::spi::FullDuplex;
 
@@ -32,11 +33,23 @@ pub struct ActiveFourWire<Spi: FullDuplex<u8>, ChipSelect: OutputPin> {
 impl<Spi: FullDuplex<u8>, ChipSelect: OutputPin> ActiveBus for ActiveFourWire<Spi, ChipSelect> {
     type Error = FourWireError<Spi::Error, ChipSelect::Error>;
     fn transfer_frame<'a>(
-        address_phase: [u8; 2],
-        control_phase: u8,
+        &mut self,
+        address_phase: u16,
+        mut control_phase: u8,
         data_phase: &'a mut [u8],
     ) -> Result<&'a mut [u8], nb::Error<Self::Error>> {
-        // TODO implement transfer
+        let mut address_bytes = [0u8; 2];
+        BigEndian::write_u16(&mut address_bytes, address_phase);
+        self.cs
+            .set_high()
+            .map_err(|e| Self::Error::ChipSelectError(e))?;
+        block!(Self::transfer_bytes(&mut self.spi, &mut address_bytes)
+            .and_then(|_| Self::transfer_byte(&mut self.spi, &mut control_phase))
+            .and_then(|_| Self::transfer_bytes(&mut self.spi, data_phase)))
+        .map_err(|e| Self::Error::SpiError(e))?;
+        self.cs
+            .set_low()
+            .map_err(|e| Self::Error::ChipSelectError(e))?;
         Ok(data_phase)
     }
 }