Send heartbeat response for better owoTrack compatibility

src/main.cpp

@@ -58,6 +58,7 @@ unsigned long blinkStart = 0;
 unsigned long now_ms, last_ms = 0; //millis() timers
 unsigned long last_battery_sample = 0;
 unsigned long const start = millis();
+bool secondImuActive = false;
 
 void setConfig(DeviceConfig newConfig)
 {
@@ -112,7 +113,6 @@ void setup()
     // Wait for IMU to boot
     delay(500);
     
-    bool secondImuActive = false;
     // Currently only second BNO08X is supported
 #if IMU == IMU_BNO080 || IMU == IMU_BNO085
     #ifdef HAS_SECOND_IMU
@@ -159,7 +159,9 @@ void loop()
         if(isConnected()) {
 #endif
     sensor.motionLoop();
+#ifdef HAS_SECOND_IMU
     sensor2.motionLoop();
+#endif
 #ifndef UPDATE_IMU_UNCONNECTED
         }
 #endif
@@ -174,7 +176,9 @@ void loop()
     if(isConnected()) {
 #endif
         sensor.sendData();
+#ifdef HAS_SECOND_IMU
         sensor2.sendData();
+#endif
 #ifndef SEND_UPDATES_UNCONNECTED
     }
 #endif

src/udpclient.cpp

@@ -298,8 +298,7 @@ void sendSerial(uint8_t *const data, int length, int type) {
     }
 }
 
-void sendSensorInfo(char const sensorId, char const sensorState, int type)
-{
+void sendSensorInfo(char const sensorId, char const sensorState, int type) {
     if (Udp.beginPacket(host, port) > 0)
     {
         sendType(type);
@@ -319,6 +318,24 @@ void sendSensorInfo(char const sensorId, char const sensorState, int type)
     }
 }
 
+void sendHeartbeat() {
+    if (Udp.beginPacket(host, port) > 0)
+    {
+        sendType(PACKET_HEARTBEAT);
+        Udp.write(convert_to_chars((uint64_t) 0, buf), sizeof(uint64_t));
+        if (Udp.endPacket() == 0)
+        {
+            //Serial.print("Write error: ");
+            //Serial.println(Udp.getWriteError());
+        }
+    }
+    else
+    {
+        //Serial.print("Write error: ");
+        //Serial.println(Udp.getWriteError());
+    }
+}
+
 void sendHandshake() {
     if (Udp.beginPacket(host, port) > 0)
     {
@@ -402,6 +419,7 @@ void clientUpdate(Sensor * const sensor, Sensor * const sensor2)
                 switch (convert_chars<int>(incomingPacket))
                 {
                 case PACKET_RECIEVE_HEARTBEAT:
+                    sendHeartbeat();
                     break;
                 case PACKET_RECIEVE_VIBRATE:
                     if(fp_commandCallback) {

src/udpclient.h

@@ -31,6 +31,7 @@
 #include "configuration.h"
 #include "sensor.h"
 
+#define PACKET_HEARTBEAT 0
 #define PACKET_ROTATION 1
 #define PACKET_GYRO 2
 #define PACKET_HANDSHAKE 3