add timeout configuration for sync serial reads

mavlink-core/src/connection/direct_serial/config.rs

@@ -1,4 +1,5 @@
 use core::fmt::Display;
+use core::time::Duration;
 
 /// MAVLink address for a serial connection
 ///
@@ -14,6 +15,7 @@ use core::fmt::Display;
 pub struct SerialConfig {
     pub(crate) port_name: String,
     pub(crate) baud_rate: u32,
+    pub(crate) timeout: Option<Duration>,
     read_buffer_capacity: usize,
 }
 
@@ -26,10 +28,23 @@ impl SerialConfig {
         Self {
             port_name,
             baud_rate,
+            timeout: None,
             read_buffer_capacity: default_capacity,
         }
     }
 
+    /// Sets the serial port timeout.
+    ///
+    /// When set, serial reads will return an error after the specified duration.
+    ///
+    /// By default, this is 1 millisecond.
+    ///
+    /// Only applies to sync connections and is a no-op for async ones.
+    pub fn timeout(mut self, timeout: Duration) -> Self {
+        self.timeout = Some(timeout);
+        self
+    }
+
     /// Updates the read buffer capacity.
     pub fn with_read_buffer_capacity(mut self, capacity: usize) -> Self {
         self.read_buffer_capacity = capacity;

mavlink-core/src/connection/direct_serial/sync.rs

@@ -106,7 +106,7 @@ impl Connectable for SerialConfig {
             .parity(Parity::None)
             .stop_bits(StopBits::One)
             .flow_control(FlowControl::None)
-            .timeout(Duration::from_millis(1))
+            .timeout(self.timeout.unwrap_or(Duration::from_millis(1)))
             .open()?;
 
         let write_port = read_port.try_clone()?;