Implemented tertiary LCD display

src/display/tertiary_lcd.rs

@@ -1 +1,88 @@
-// Tertiary LCD module
+use embedded_hal::i2c::I2c;
+use esp_hal::delay::Delay;
+use i2c_character_display::{CharacterDisplayPCF8574T, LcdDisplayType};
+use log::error;
+
+pub type TertiaryLcd<I2C> = CharacterDisplayPCF8574T<I2C, Delay>;
+
+pub fn init_tertiary_lcd<I2C>(i2c: I2C) -> TertiaryLcd<I2C>
+where
+    I2C: I2c,
+{
+    let mut lcd = CharacterDisplayPCF8574T::new(i2c, LcdDisplayType::Lcd16x2, Delay::new());
+    match lcd.init() {
+        Ok(()) => {
+            log::info!("I2C tertiary LCD initialized on PCF8574T at address 0x27");
+            lcd
+        }
+        Err(_) => {
+            error!("I2C tertiary LCD init failed on PCF8574T at address 0x27; check bus wiring, power, and device address");
+            panic!("tertiary LCD initialization failed");
+        }
+    }
+}
+
+pub fn write_line<I2C>(
+    lcd: &mut TertiaryLcd<I2C>,
+    line: u8,
+    text: &str,
+) -> Result<(), i2c_character_display::CharacterDisplayError<I2C>>
+where
+    I2C: I2c,
+{
+    if let Err(e) = lcd.set_cursor(0, line) {
+        error!("I2C LCD cursor move failed on line {line}; bus or device may be unavailable");
+        return Err(e);
+    }
+    if let Err(e) = lcd.print(text) {
+        error!("I2C LCD print failed on line {line}; payload length={} and device may be busy or disconnected", text.len());
+        return Err(e);
+    }
+    Ok(())
+}
+
+pub fn write_wrapped<I2C>(
+    lcd: &mut TertiaryLcd<I2C>,
+    text: &str,
+) -> Result<(), i2c_character_display::CharacterDisplayError<I2C>>
+where
+    I2C: I2c,
+{
+    const DISPLAY_WIDTH: usize = 16;
+    const DISPLAY_ROWS: usize = 2;
+
+    if let Err(e) = lcd.clear() {
+        error!("I2C LCD clear failed before wrapped write; check the shared bus and display response");
+        return Err(e);
+    }
+
+    let mut offset = 0;
+    for row in 0..DISPLAY_ROWS {
+        let remaining = &text[offset..];
+        if remaining.is_empty() {
+            return Ok(());
+        }
+
+        let chunk = if remaining.len() > DISPLAY_WIDTH {
+            &remaining[..DISPLAY_WIDTH]
+        } else {
+            remaining
+        };
+
+        if let Err(e) = lcd.set_cursor(0, row as u8) {
+            error!("I2C LCD cursor move failed while writing wrapped row {row}; bus may be busy or device unresponsive");
+            return Err(e);
+        }
+        if let Err(e) = lcd.print(chunk) {
+            error!("I2C LCD wrapped write failed on row {row}; chunk length={} and text may exceed display width", chunk.len());
+            return Err(e);
+        }
+        offset += chunk.len();
+
+        if offset >= text.len() {
+            return Ok(());
+        }
+    }
+
+    Ok(())
+}