working everything properly well

mqtt_display/src/contracts.rs

@@ -0,0 +1,35 @@
+// src/contracts.rs
+//! Cross-feature message contracts.
+//! 
+//! This is the ONLY coupling point between features.
+//! Features depend on these types, not on each other.
+
+use heapless::String as HString;
+
+/// IMU sensor reading from MPU6050
+#[derive(Clone, Copy, Default, Debug)]
+pub struct ImuReading {
+    /// Acceleration in g (earth gravity units)
+    pub accel_g: [f32; 3],
+    /// Angular velocity in degrees per second
+    pub gyro_dps: [f32; 3],
+    /// Temperature in Celsius
+    pub temp_c: f32,
+    /// Timestamp in milliseconds since boot
+    pub timestamp_ms: u64,
+}
+
+/// Commands that can be sent to the display actor
+#[derive(Clone, Debug)]
+pub enum DisplayCommand {
+    /// Show IMU sensor data
+    SetImu(ImuReading),
+    /// Show a status line (max 32 chars)
+    SetStatus(HString<32>),
+    /// Show an error message (max 64 chars)
+    ShowError(HString<64>),
+    /// Show MQTT connection status
+    SetMqttStatus { connected: bool, msg_count: u32 },
+    /// Clear the display to default state
+    Clear,
+}