Started driver implementation

src/lib.rs

@@ -0,0 +1,110 @@
+#![no_std]
+
+use embedded_hal::{
+    delay::DelayNs,
+    digital::{InputPin, OutputPin}, spi::{Operation, SpiDevice},
+};
+
+const EPD_WIDTH: u32 = 240;
+const EPD_HEIGHT: u32 = 320;
+const EPD_ARRAY: u32 = EPD_WIDTH * EPD_HEIGHT / 8;
+
+pub struct EPaperDisplay<BusyPin, ResetPin, DcPin, SpiDevice, Delay> {
+    busy: BusyPin,
+    reset: ResetPin,
+    dc: DcPin,
+    spi: SpiDevice,
+    delay: Delay,
+}
+
+pub enum InitError<ResetError, DcError, SpiError> {
+    ResetError(ResetError),
+    WriteError(WriteError<DcError, SpiError>),
+}
+
+pub enum WriteError<DcError, SpiError> {
+    DcError(DcError),
+    SpiError(SpiError),
+}
+
+impl<
+    BusyPin: InputPin,
+    ResetPin: OutputPin,
+    DcPin: OutputPin,
+    Spi: SpiDevice,
+    Delay: DelayNs,
+> EPaperDisplay<BusyPin, ResetPin, DcPin, Spi, Delay>
+{
+    pub fn new(
+        busy: BusyPin,
+        reset: ResetPin,
+        dc: DcPin,
+        spi: Spi,
+        delay: Delay,
+    ) -> Result<Self, InitError<ResetPin::Error, DcPin::Error, Spi::Error>> {
+        let mut display = Self {
+            busy,
+            reset,
+            dc,
+            spi,
+            delay,
+        };
+        display.init().map(|_| display)
+    }
+
+    fn write_command(&mut self, byte: u8) -> Result<(), WriteError<DcPin::Error, Spi::Error>> {
+        self.dc.set_low().map_err(WriteError::DcError)?;
+        self.spi.transaction(&mut [
+            Operation::DelayNs(60),
+            Operation::Write(&[byte]),
+            Operation::DelayNs(20),
+        ]).map_err(WriteError::SpiError)?;
+        self.delay.delay_ns(40);
+        Ok(())
+    }
+
+    fn write_data(&mut self, byte: u8) -> Result<(), WriteError<DcPin::Error, Spi::Error>> {
+        self.dc.set_high().map_err(WriteError::DcError)?;
+        self.spi.transaction(&mut [
+            Operation::DelayNs(60),
+            Operation::Write(&[byte]),
+            Operation::DelayNs(20),
+        ]).map_err(WriteError::SpiError)?;
+        self.delay.delay_ns(40);
+        Ok(())
+    }
+
+    fn wait_for_display(&mut self) {
+        while self.busy.is_low().expect("Failed to read busy pin") {}
+    }
+
+    fn init(&mut self) -> Result<(), InitError<ResetPin::Error, DcPin::Error, Spi::Error>> {
+        self.reset.set_low().map_err(InitError::ResetError)?;
+        self.delay.delay_ms(10);
+        self.reset.set_high().map_err(InitError::ResetError)?;
+        self.delay.delay_ms(10);
+
+        self.write_command(0x00).map_err(InitError::WriteError)?;
+        self.write_data(0x1f).map_err(InitError::WriteError)?;
+        self.write_command(0x04).map_err(InitError::WriteError)?;
+
+        self.wait_for_display();
+
+        Ok(())
+    }
+
+    fn clear_display(&mut self) {
+        self.write_command(0x10);
+        for _ in 0..EPD_ARRAY {
+            self.write_data(0xff);
+        }
+        self.write_command(0x13);
+        for _ in 0..EPD_ARRAY {
+            self.write_data(0xff);
+        }
+        self.write_command(0x12);
+
+        self.delay.delay_ms(1);
+        self.wait_for_display();
+    }
+}