Arduino frameworks

- AltSoftSerial UART with WT61 IMU
- UART with Pi on TX0/RX0 (and USB)

arduino/main/comms.h

@@ -0,0 +1,25 @@
+#ifndef COMMS_H
+#define COMMS_H
+
+#include <Arduino.h>
+
+// Initialize Pi serial communication (call in setup)
+void comms_init();
+
+// Process incoming commands from Pi - call in loop
+// Returns true if a complete command was received
+bool comms_update();
+
+// Send telemetry line to Pi
+void comms_send(const char* key, float value, int decimals = 2);
+void comms_send(const char* key, int value);
+void comms_send(const char* key, const char* value);
+
+// Get last received command (empty if none)
+// Command buffer is cleared after reading
+const char* comms_get_command();
+
+// Check if connected (received any data recently)
+bool comms_is_connected(unsigned long timeout_ms = 5000);
+
+#endif