APM 2.1 - No flight data transmission (Unusual LED behavior/wrong setup?) - Discussions

I have previously had success flight testing my Skywalker EPO UAV with ArduPilotMega. Both stabilize and fly by wire A functions worked flawlessly, but due to safety issues I wanted to embed a bidirectional radiolink before attempting autonomous flights. As the 900MHz band is already used for the GSM band in Norway, I selected the Xbee PRO 2.4GHz series 1 U.FL version, and a 35MHz transmitter for the RC side of the system.

Using Digi software I have verified that the links are correctly set up, and also communciates correctly when doing the xbee test in CLI mode. However, when I turn the CLI switch to flight mode I have not been able to receive data from the APM using the radiolink (currently using APM 2.1 and HK GCS v1.2.92). I'm nevertheless suspecting the error to be in the config-file or APM setup as only the "B" led turns solid after IMU calibration, -while led "C" is no longer flashing nor turning solid (GPS lock) like expected. When doing the previously mentioned test-flights the "ABC"-LED's have showed the correct behaviour, so this is a bit suprising to me. Moreover, there the RX and TX LEDs do not flash, indicating to me that no data is being transmitted to the Xbee link

The APM_Config.h file contains the following code lines:

#define GPS_PROTOCOL GPS_PROTOCOL_MTK16

#define AIRSPEED_SENSOR ENABLED

#define SERIAL3_BAUD 57600

#define GCS_PORT 3

#define GCS_PROTOCOL GCS_PROTOCOL_LEGACY

The APM 2.1. software compiles and uploads without any error messages. I'm sure I must be doing something wrong, but would really appreciate some advices as to put me back on track! I'm however still able to connect with HK GCS and receive flight data although only via the USB, - not very helpful when flying.. HK baudrate is set to 57600 and after connection the only raw data appearing in the HK serial window is as following:

OUT:$Q,0,0*51

Checking 57600 baud

I have previously had success flight testing my Skywalker UAV with ArduPilotMega. Both stabilize and fly by wire A functions workedflawlessly, but due to safety issues I wanted to embed a bidirectionalradiolink before attempting autonomous flights. As the 900MHz band isalready used for the GSM band in Norway, I selected the Xbee PRO 2.4GHzseries 1 U.FL version, and a 35MHz transmitter for the RC side of thesystem.

Using Digi software I have verified that the links are correctly set up, and also communciates correctly when doingthe xbee test in CLI mode. However, when I turn the CLI switch to flightmode I have not been able to connect with the APM (currently using APM2.1 and HK GCS v1.2.92). I'm nevertheless suspecting the error to be inthe config-file or APM setup as only the "B" led turns solid after IMUcalibration, -while led "C" is no longer flashing nor turning solid (GPSlock) like expected. When doing the previously mentioned test-flightsthe "ABC"-LED's have showed the correct behaviour, so this is a bitsuprising to me. Moreover, there the RX and TX LEDs do not flash,indicating to me that no data is being transmitted to the Xbee link

The APM_Config.h file contains the following code lines:

#define GPS_PROTOCOL GPS_PROTOCOL_MTK16

#define AIRSPEED_SENSOR ENABLED

#define SERIAL3_BAUD 57600

#define GCS_PORT 3

#define GCS_PROTOCOL GCS_PROTOCOL_LEGACY

The APM 2.1. software compiles and uploads without any error messages. I'msure I must be doing something wrong, and would really appreciate someadvices to put me back on track. I'm however still able to connect withHK GCS and receive flight data but only via the USB, so that's not goingto be very helpful when flying...

Replies

Arve Tokheim May 4, 2011 at 5:33am

Thanks for the correction Michael. I recompiled and uploaded the code. Guess that gets me a step closer, but I'm still not seeing any flight data coming from the APM when using the Xbee link. After IMU config only the "B" LED turns on, still no "C" LED. I did however notice that when I attempt to send data over the link, the ASC/RSSI LED turns solid red for a few seconds on the Xbee adapter on the airplane side.
Developer

Michael Oborne May 4, 2011 at 3:54am

define GCS_PROTOCOL GCS_PROTOCOL_LEGACY does not exist in 2.1, you must use mavlink. recompile without that option

This reply was deleted.