Various improvements (#25)

- Added is_busy to Waveshare_Interface
- Added IS_BUSY_LOW const for all supported epds
- Added is_busy to DisplayInterface
- moved width, height and default_background_color directly to epd4in2 module
- Added VarDisplay (a variable buffersize display/graphic driver)
- Removed all Buffers (Buffer1in54,...) and instead made specialised Displays (Display1in54,...) with included Buffers
- Updated and added more examples
- Cargo fmt/clippy
- Improved Docs/Readmes

examples/epd4in2_full/src/main.rs

@@ -0,0 +1,189 @@
+#![deny(warnings)]
+
+use embedded_graphics::{
+    coord::Coord,
+    fonts::{Font12x16, Font6x8},
+    prelude::*,
+    primitives::{Circle, Line},
+    Drawing,
+};
+use embedded_hal::prelude::*;
+use epd_waveshare::{
+    epd4in2::{Display4in2, EPD4in2},
+    graphics::{Display, DisplayRotation},
+    prelude::*,
+};
+use linux_embedded_hal::{
+    spidev::{self, SpidevOptions},
+    sysfs_gpio::Direction,
+    Delay, Pin, Spidev,
+};
+
+// activate spi, gpio in raspi-config
+// needs to be run with sudo because of some sysfs_gpio permission problems and follow-up timing problems
+// see https://github.com/rust-embedded/rust-sysfs-gpio/issues/5 and follow-up issues
+
+fn main() {
+    if let Err(e) = run() {
+        eprintln!("Program exited early with error: {}", e);
+    }
+}
+
+fn run() -> Result<(), std::io::Error> {
+    // Configure SPI
+    // Settings are taken from
+    let mut spi = Spidev::open("/dev/spidev0.0").expect("spidev directory");
+    let options = SpidevOptions::new()
+        .bits_per_word(8)
+        .max_speed_hz(4_000_000)
+        .mode(spidev::SPI_MODE_0)
+        .build();
+    spi.configure(&options).expect("spi configuration");
+
+    // Configure Digital I/O Pin to be used as Chip Select for SPI
+    let cs = Pin::new(26); //BCM7 CE0
+    cs.export().expect("cs export");
+    while !cs.is_exported() {}
+    cs.set_direction(Direction::Out).expect("CS Direction");
+    cs.set_value(1).expect("CS Value set to 1");
+
+    let busy = Pin::new(5); //pin 29
+    busy.export().expect("busy export");
+    while !busy.is_exported() {}
+    busy.set_direction(Direction::In).expect("busy Direction");
+    //busy.set_value(1).expect("busy Value set to 1");
+
+    let dc = Pin::new(6); //pin 31 //bcm6
+    dc.export().expect("dc export");
+    while !dc.is_exported() {}
+    dc.set_direction(Direction::Out).expect("dc Direction");
+    dc.set_value(1).expect("dc Value set to 1");
+
+    let rst = Pin::new(16); //pin 36 //bcm16
+    rst.export().expect("rst export");
+    while !rst.is_exported() {}
+    rst.set_direction(Direction::Out).expect("rst Direction");
+    rst.set_value(1).expect("rst Value set to 1");
+
+    let mut delay = Delay {};
+
+    let mut epd4in2 =
+        EPD4in2::new(&mut spi, cs, busy, dc, rst, &mut delay).expect("eink initalize error");
+
+    println!("Test all the rotations");
+    let mut display = Display4in2::default();
+    display.set_rotation(DisplayRotation::Rotate0);
+    display.draw(
+        Font6x8::render_str("Rotate 0!")
+            .with_stroke(Some(Color::Black))
+            .with_fill(Some(Color::White))
+            .translate(Coord::new(5, 50))
+            .into_iter(),
+    );
+
+    display.set_rotation(DisplayRotation::Rotate90);
+    display.draw(
+        Font6x8::render_str("Rotate 90!")
+            .with_stroke(Some(Color::Black))
+            .with_fill(Some(Color::White))
+            .translate(Coord::new(5, 50))
+            .into_iter(),
+    );
+
+    display.set_rotation(DisplayRotation::Rotate180);
+    display.draw(
+        Font6x8::render_str("Rotate 180!")
+            .with_stroke(Some(Color::Black))
+            .with_fill(Some(Color::White))
+            .translate(Coord::new(5, 50))
+            .into_iter(),
+    );
+
+    display.set_rotation(DisplayRotation::Rotate270);
+    display.draw(
+        Font6x8::render_str("Rotate 270!")
+            .with_stroke(Some(Color::Black))
+            .with_fill(Some(Color::White))
+            .translate(Coord::new(5, 50))
+            .into_iter(),
+    );
+
+    epd4in2.update_frame(&mut spi, &display.buffer()).unwrap();
+    epd4in2
+        .display_frame(&mut spi)
+        .expect("display frame new graphics");
+    delay.delay_ms(5000u16);
+
+    println!("Now test new graphics with default rotation and some special stuff:");
+    display.clear_buffer(Color::White);
+
+    // draw a analog clock
+    display.draw(
+        Circle::new(Coord::new(64, 64), 64)
+            .with_stroke(Some(Color::Black))
+            .into_iter(),
+    );
+    display.draw(
+        Line::new(Coord::new(64, 64), Coord::new(0, 64))
+            .with_stroke(Some(Color::Black))
+            .into_iter(),
+    );
+    display.draw(
+        Line::new(Coord::new(64, 64), Coord::new(80, 80))
+            .with_stroke(Some(Color::Black))
+            .into_iter(),
+    );
+
+    // draw white on black background
+    display.draw(
+        Font6x8::render_str("It's working-WoB!")
+            // Using Style here
+            .with_style(Style {
+                fill_color: Some(Color::Black),
+                stroke_color: Some(Color::White),
+                stroke_width: 0u8, // Has no effect on fonts
+            })
+            .translate(Coord::new(175, 250))
+            .into_iter(),
+    );
+
+    // use bigger/different font
+    display.draw(
+        Font12x16::render_str("It's working-BoW!")
+            // Using Style here
+            .with_style(Style {
+                fill_color: Some(Color::White),
+                stroke_color: Some(Color::Black),
+                stroke_width: 0u8, // Has no effect on fonts
+            })
+            .translate(Coord::new(50, 200))
+            .into_iter(),
+    );
+
+    // a moving `Hello World!`
+    let limit = 10;
+    for i in 0..limit {
+        println!("Moving Hello World. Loop {} from {}", (i + 1), limit);
+
+        display.draw(
+            Font6x8::render_str("  Hello World! ")
+                .with_style(Style {
+                    fill_color: Some(Color::White),
+                    stroke_color: Some(Color::Black),
+                    stroke_width: 0u8, // Has no effect on fonts
+                })
+                .translate(Coord::new(5 + i * 12, 50))
+                .into_iter(),
+        );
+
+        epd4in2.update_frame(&mut spi, &display.buffer()).unwrap();
+        epd4in2
+            .display_frame(&mut spi)
+            .expect("display frame new graphics");
+
+        delay.delay_ms(1_000u16);
+    }
+
+    println!("Finished tests - going to sleep");
+    epd4in2.sleep(&mut spi)
+}