Add epd2in9bc to README, add example

src/epd1in54/mod.rs

@@ -30,7 +30,7 @@
 //!    .into_styled(PrimitiveStyle::with_stroke(Black, 1))
 //!    .draw(&mut display);
 //!
-//!    // Display updated frame
+//!// Display updated frame
 //!epd.update_frame(&mut spi, &display.buffer())?;
 //!epd.display_frame(&mut spi)?;
 //!

src/epd2in9bc/mod.rs

@@ -1,4 +1,58 @@
 //! A simple Driver for the Waveshare 2.9" (B/C) E-Ink Display via SPI
+//!
+//! # Example for the 2.9" E-Ink Display
+//!
+//!```rust, no_run
+//!# use embedded_hal_mock::*;
+//!# fn main() -> Result<(), MockError> {
+//!use embedded_graphics::{
+//!    pixelcolor::BinaryColor::On as Black, prelude::*, primitives::Line, style::PrimitiveStyle,
+//!};
+//!use epd_waveshare::{epd2in9bc::*, prelude::*};
+//!#
+//!# let expectations = [];
+//!# let mut spi = spi::Mock::new(&expectations);
+//!# let expectations = [];
+//!# let cs_pin = pin::Mock::new(&expectations);
+//!# let busy_in = pin::Mock::new(&expectations);
+//!# let dc = pin::Mock::new(&expectations);
+//!# let rst = pin::Mock::new(&expectations);
+//!# let mut delay = delay::MockNoop::new();
+//!
+//!// Setup EPD
+//!let mut epd = EPD2in9bc::new(&mut spi, cs_pin, busy_in, dc, rst, &mut delay)?;
+//!
+//!// Use display graphics from embedded-graphics
+//!// This display is for the black/white pixels
+//!let mut mono_display = Display2in9bc::default();
+//!
+//!// Use embedded graphics for drawing
+//!// A black line
+//!let _ = Line::new(Point::new(0, 120), Point::new(0, 200))
+//!    .into_styled(PrimitiveStyle::with_stroke(Black, 1))
+//!    .draw(&mut mono_display);
+//!
+//!// Use a second display for red/yellow
+//!let mut chromatic_display = Display2in9bc::default();
+//!
+//!// We use `Black` but it will be shown as red/yellow
+//!let _ = Line::new(Point::new(15, 120), Point::new(15, 200))
+//!    .into_styled(PrimitiveStyle::with_stroke(Black, 1))
+//!    .draw(&mut chromatic_display);
+//!
+//!// Display updated frame
+//!epd.update_color_frame(
+//!    &mut spi,
+//!    &mono_display.buffer(),
+//!    &chromatic_display.buffer()
+//!)?;
+//!epd.display_frame(&mut spi)?;
+//!
+//!// Set the EPD to sleep
+//!epd.sleep(&mut spi)?;
+//!# Ok(())
+//!# }
+//!```
 use embedded_hal::{
     blocking::{delay::*, spi::Write},
     digital::v2::*,