Add HD44780 example (#60)

* Added HD44780 lcd example

* Formatting lcd_display.rs

* Formatting Cargo.toml

* Fixed import formatting issue

* Fixed line with spaces

rp2040-hal/Cargo.toml

@@ -21,6 +21,7 @@ paste = "1.0"
 cortex-m-rt = "0.6.14"
 panic-halt = "0.2.0"
 rp2040-boot2 = { git = "https://github.com/rp-rs/rp2040-boot2-rs", branch="main" }
+hd44780-driver = "0.4.0"
 
 [features]
-rt = ["rp2040-pac/rt"]
+rt = ["rp2040-pac/rt"]

rp2040-hal/examples/lcd_display.rs

@@ -0,0 +1,52 @@
+#![no_std]
+#![no_main]
+
+use cortex_m_rt::entry;
+use hal::pac;
+use hal::sio::Sio;
+use hd44780_driver as hd44780;
+use panic_halt as _;
+use rp2040_hal as hal;
+
+#[link_section = ".boot2"]
+#[used]
+pub static BOOT2: [u8; 256] = rp2040_boot2::BOOT_LOADER;
+
+#[entry]
+fn main() -> ! {
+    let mut pac = pac::Peripherals::take().unwrap();
+    let core = pac::CorePeripherals::take().unwrap();
+
+    // AHL bus speed default
+    let mut delay_provider = cortex_m::delay::Delay::new(core.SYST, 12_000_000);
+
+    let sio = Sio::new(pac.SIO);
+    let pins = hal::gpio::Pins::new(
+        pac.IO_BANK0,
+        pac.PADS_BANK0,
+        sio.gpio_bank0,
+        &mut pac.RESETS,
+    );
+
+    let lcd = hd44780::HD44780::new_4bit(
+        pins.gpio16.into_push_pull_output(), // Register Select
+        pins.gpio17.into_push_pull_output(), // Enable
+        pins.gpio18.into_push_pull_output(), // d4
+        pins.gpio19.into_push_pull_output(), // d5
+        pins.gpio20.into_push_pull_output(), // d6
+        pins.gpio21.into_push_pull_output(), // d7
+        &mut delay_provider,
+    );
+
+    let mut lcd = lcd.unwrap();
+
+    lcd.reset(&mut delay_provider).unwrap();
+    lcd.clear(&mut delay_provider).unwrap();
+    lcd.write_str("rp-hal on", &mut delay_provider).unwrap();
+    lcd.set_cursor_pos(40, &mut delay_provider).unwrap();
+    lcd.set_cursor_visibility(hd44780::Cursor::Visible, &mut delay_provider)
+        .unwrap();
+    lcd.write_str("HD44780!", &mut delay_provider).unwrap();
+
+    loop {}
+}