APM2 Telemetry rate

I need some expert APM2 Telemetry help.I'm using the Xbee XSC 900mhz units. Which sadly have a maximum RF baud rate of 9600.I'v managed to configure the SERIAL3_BAUD to "9" for 9600 (also tried "4" / 4800) and I'm able to recieve telemetry data from the APM2 well. The problem lies trying to send data to the APM2 from the PC. It appears this data never makes it, in a loop-back test under X-CTU works fine.The TX/RX activity indication LED's are constantly on. I have configured a forced delay in TX per module with X-CTU every 2048 bytes. Now I am able to get small amounts of data to the APM2 from the PC. It would thus appear that the TX stream from the APM2 is overloading the data rate for 9600 even though its configured for it.I read somewhere that the telemetry stream can be configured in Hz refresh rate, but unable to find a parameter to configure for it.If I could slow down the data stream for the APM2 telemetry I believe I could effectively make use of these XSC Xbee modules.Simply put, my assumption is the telemetry stream bandwidth is more than can be handled @9600 baud.Any thoughts?

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  • Hi all,

    i tested "MultiSerialMega" with Serial and Serial3 at 9600 baud, i received "Port 0" in both case, from USB and then from wireless when power by battery. So, i want to set Telemetry in Serial port.

    I have to do 2 change. First, set Serial baud rate to 9600 instead 115200. Second, set telemetry to Serial port instead Serial3. I guess i need to modify source code and compile in Arduino IDE, so i downloaded.

    i start to work with ardupilot 4 days ago, i'm learning but i'm lost yet.

    i haven't found begin instruction to Serial, i saw this:

    FastSerialPort0(Serial);        // FTDI/console
    FastSerialPort1(Serial1);       // GPS port
    FastSerialPort3(Serial3);       // Telemetry port

    How setup Telemetry in Serial port? just "FastSerialPort3(Serial);" do this have sense?

    where is Serial "baud rate parameter" in source code? i have searched Serial.begin() without success.

    i would appreciate any help. Thanks

    PD: i don't want cut AutoMux microwire neither solder to UART2 (Serial3).

  • Mike, can you please elaborate? I think what your pointing out is that at 100% duty cycle Tx will never cease to allow the module to stop and listen. How can I slow the telemetry stream to get below 100% duty cycle of the xbee?

  • Moderator
    Yes, also, lookup "duty cycle" and check the radio's spec sheet.
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