APM: added new TELEM_DELAY parameter

number of seconds to delay telemetry

ArduPlane/GCS_Mavlink.pde

@@ -474,15 +474,38 @@ static void NOINLINE send_statustext(mavlink_channel_t chan)
         pending_status.text);
 }
 
+// are we still delaying telemetry to try to avoid Xbee bricking?
+static bool telemetry_delayed(mavlink_channel_t chan)
+{
+    uint32_t tnow = millis() >> 10;
+    if (tnow > g.telem_delay) {
+        return false;
+    }
+#if USB_MUX_PIN > 0
+    if (chan == MAVLINK_COMM_0 && usb_connected) {
+        // this is an APM2 with USB telemetry
+        return false;
+    }
+    // we're either on the 2nd UART, or no USB cable is connected
+    // we need to delay telemetry
+    return true;
+#else
+    if (chan == MAVLINK_COMM_0) {
+        // we're on the USB port
+        return false;
+    }
+    // don't send telemetry yet
+    return true;
+#endif
+}
+
 
 // try to send a message, return false if it won't fit in the serial tx buffer
 static bool mavlink_try_send_message(mavlink_channel_t chan, enum ap_message id, uint16_t packet_drops)
 {
     int16_t payload_space = comm_get_txspace(chan) - MAVLINK_NUM_NON_PAYLOAD_BYTES;
 
-    if (chan == MAVLINK_COMM_1 && millis() < MAVLINK_TELEMETRY_PORT_DELAY) {
-        // defer any messages on the telemetry port for 1 second after
-        // bootup, to try to prevent bricking of Xbees
+    if (telemetry_delayed(chan)) {
         return false;
     }
 
@@ -693,9 +716,7 @@ static void mavlink_send_message(mavlink_channel_t chan, enum ap_message id, uin
 
 void mavlink_send_text(mavlink_channel_t chan, gcs_severity severity, const char *str)
 {
-    if (chan == MAVLINK_COMM_1 && millis() < MAVLINK_TELEMETRY_PORT_DELAY) {
-        // don't send status MAVLink messages for 2 seconds after
-        // bootup, to try to prevent Xbee bricking
+    if (telemetry_delayed(chan)) {
         return;
     }
 

ArduPlane/Parameters.h

@@ -81,6 +81,7 @@ public:
         k_param_sysid_this_mav,
         k_param_sysid_my_gcs,
         k_param_serial3_baud,
+        k_param_telem_delay,
 
         // 120: Fly-by-wire control
         //
@@ -219,6 +220,7 @@ public:
     AP_Int16 sysid_this_mav;
     AP_Int16 sysid_my_gcs;
     AP_Int8 serial3_baud;
+    AP_Int8 telem_delay;
 
     // Feed-forward gains
     //

ArduPlane/Parameters.pde

@@ -26,6 +26,15 @@ const AP_Param::Info var_info[] PROGMEM = {
     // @User: Standard
     GSCALAR(serial3_baud,           "SERIAL3_BAUD",   SERIAL3_BAUD/1000),
 
+    // @Param: TELEM_DELAY
+    // @DisplayName: Telemetry startup delay 
+    // @Description: The amount of time (in seconds) to delay radio telemetry to prevent an Xbee bricking on power up
+    // @User: Standard
+    // @Units: seconds
+    // @Range: 0 10
+    // @Increment: 1
+    GSCALAR(telem_delay,            "TELEM_DELAY",     0),
+
     // @Param: KFF_PTCHCOMP
     // @DisplayName: Pitch Compensation
     // @Description: Adds pitch input to compensate for the loss of lift due to roll control. 0 = 0 %, 1 = 100%

ArduPlane/config.h

@@ -816,11 +816,6 @@
  # define CLI_ENABLED ENABLED
 #endif
 
-// delay to prevent Xbee bricking, in milliseconds
-#ifndef MAVLINK_TELEMETRY_PORT_DELAY
- # define MAVLINK_TELEMETRY_PORT_DELAY 6000
-#endif
-
 // use this to disable geo-fencing
 #ifndef GEOFENCE_ENABLED
  # define GEOFENCE_ENABLED ENABLED