Move examples to a package of their own (#16)

* Move examples to a package of their own

* cargo +nightly fmt

* Add missing safety doc

* cargo clippy examples

* fmt again

---------

Co-authored-by: Felipe Balbi <[email protected]>

1 files changed, 111 insertions, 0 deletions

diff --git a/examples/src/bin/hello.rs b/examples/src/bin/hello.rs
new file mode 100644
index 000000000..5c4336d50
--- /dev/null
+++ b/examples/src/bin/hello.rs
@@ -0,0 +1,111 @@
+#![no_std]
+#![no_main]
+
+use embassy_executor::Spawner;
+use embassy_mcxa_examples::init_uart2;
+use hal::uart;
+use {defmt_rtt as _, embassy_mcxa as hal, panic_probe as _};
+
+/// Simple helper to write a byte as hex to UART
+fn write_hex_byte(uart: &hal::uart::Uart<hal::uart::Lpuart2>, byte: u8) {
+    const HEX_DIGITS: &[u8] = b"0123456789ABCDEF";
+    uart.write_byte(HEX_DIGITS[(byte >> 4) as usize]);
+    uart.write_byte(HEX_DIGITS[(byte & 0xF) as usize]);
+}
+
+#[embassy_executor::main]
+async fn main(_spawner: Spawner) {
+    let p = hal::init(hal::config::Config::default());
+
+    defmt::info!("boot");
+
+    // Board-level init for UART2 clocks and pins.
+    unsafe {
+        init_uart2(hal::pac());
+    }
+
+    // Get UART source frequency from clock configuration
+    // Using hardcoded frequency for now - dynamic detection may have issues
+    let src = 12_000_000; // FRO_LF_DIV at 12MHz with DIV=0
+    let uart = uart::Uart::<uart::Lpuart2>::new(p.LPUART2, uart::Config::new(src));
+
+    // Print welcome message before any async delays to guarantee early console output
+    uart.write_str_blocking("\r\n=== MCXA276 UART Echo Demo ===\r\n");
+    uart.write_str_blocking("Available commands:\r\n");
+    uart.write_str_blocking("  help     - Show this help\r\n");
+    uart.write_str_blocking("  echo <text> - Echo back the text\r\n");
+    uart.write_str_blocking("  hex <byte> - Display byte in hex (0-255)\r\n");
+    uart.write_str_blocking("Type a command: ");
+
+    let mut buffer = [0u8; 64];
+    let mut buf_idx = 0;
+
+    loop {
+        // Read a byte from UART
+        let byte = uart.read_byte_blocking();
+
+        // Echo the character back
+        if byte == b'\r' || byte == b'\n' {
+            // Enter pressed - process command
+            uart.write_str_blocking("\r\n");
+
+            if buf_idx > 0 {
+                let command = &buffer[0..buf_idx];
+
+                if command == b"help" {
+                    uart.write_str_blocking("Available commands:\r\n");
+                    uart.write_str_blocking("  help     - Show this help\r\n");
+                    uart.write_str_blocking("  echo <text> - Echo back the text\r\n");
+                    uart.write_str_blocking("  hex <byte> - Display byte in hex (0-255)\r\n");
+                } else if command.starts_with(b"echo ") && command.len() > 5 {
+                    uart.write_str_blocking("Echo: ");
+                    uart.write_str_blocking(core::str::from_utf8(&command[5..]).unwrap_or(""));
+                    uart.write_str_blocking("\r\n");
+                } else if command.starts_with(b"hex ") && command.len() > 4 {
+                    // Parse the byte value
+                    let num_str = &command[4..];
+                    if let Ok(num) = parse_u8(num_str) {
+                        uart.write_str_blocking("Hex: 0x");
+                        write_hex_byte(&uart, num);
+                        uart.write_str_blocking("\r\n");
+                    } else {
+                        uart.write_str_blocking("Invalid number for hex command\r\n");
+                    }
+                } else if !command.is_empty() {
+                    uart.write_str_blocking("Unknown command: ");
+                    uart.write_str_blocking(core::str::from_utf8(command).unwrap_or(""));
+                    uart.write_str_blocking("\r\n");
+                }
+            }
+
+            // Reset buffer and prompt
+            buf_idx = 0;
+            uart.write_str_blocking("Type a command: ");
+        } else if byte == 8 || byte == 127 {
+            // Backspace
+            if buf_idx > 0 {
+                buf_idx -= 1;
+                uart.write_str_blocking("\x08 \x08"); // Erase character
+            }
+        } else if buf_idx < buffer.len() - 1 {
+            // Regular character
+            buffer[buf_idx] = byte;
+            buf_idx += 1;
+            uart.write_byte(byte);
+        }
+    }
+}
+
+/// Simple parser for u8 from ASCII bytes
+fn parse_u8(bytes: &[u8]) -> Result<u8, ()> {
+    let mut result = 0u8;
+    for &b in bytes {
+        if b.is_ascii_digit() {
+            result = result.checked_mul(10).ok_or(())?;
+            result = result.checked_add(b - b'0').ok_or(())?;
+        } else {
+            return Err(());
+        }
+    }
+    Ok(result)
+}