No signal on APM2.0 UART0 and XBEE issue

Hi

My setup is as following:

APM 2.0

XBee-PRO 900 extended range module w/ RPSMA connector  (Laptop Side)  XBP09-DM Firmware 1061

DIYDrone XtreamBee USB Adapter (Laptop Side)

XBee-PRO 900 extended range module w/ wire antenna (APM 2.0 side) XBP09-DM Firmware 1061

DIYDrone XtreamBee Board (APM 2.0 Side).

  • I’m able to successfully test Airlink between the two XBEEs using X-CTU and loopback.
  • I’m able to receive test text over the air link when I use serial testing sketch on APM2.0 board, connecting the XBEE to the side UART0
  • I soldered the UART0/2 MUX jumpers on the bottom of APM 2.0 to select UART0

My 1st Issue is I’m not able to see any signal on the back UART0 connector even when I load the serial test sketch which is giving perfect output on the side UART0. Is this a known bug in APM 2.0 board ?

My 2nd Issue is that I’m not able to establish telemetry over the airlink, I tried 57K & 115K baud rates, I tried HKGCS & APM Planner but no luck (Even when using the long side UART0 port)

Please help me.

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Replies

  • Hi Guys!

    I'm having the same problem as you! The Uart0/2 stopped sending data to my xbee! I haven't tried the UART0 solo... If that does not work do you have other solutions?

    I'm also having some sort of problem when loading a new firmware, when verifying it gives me a strange error, something related to the port not being found or in use, I am not sure! Tomorrow I will post a picture.

    Best Regards,

    AS

  • OK, after i was able to establish a link via the hardwired UART0 port, now i just can't. I wonder WHY. it was able to fetch parameters then eventually fail due to (link isn't fast enogh), but i thought it would work using full battery and ESC power as stated by some other client. Now, it won't connect at all!! I even soldered the UART0/2 MUX, but with no success!!

    PLEASE, HELP !! and can anyone explain a workaround or a procedure to follow to detect where the failure is ? and what about the failed MUX problem i read in another thread ?! 

  • My 2.4.1 board appears to have no micro traces in place (I have a second that is identical with no traces) and the UART does not work. Can connect with USB and flies fine, have a separate issue with the TX/RX LED's that I think may be related. Can you include within the WIKI a good high resolution image of the PCB's so that all the relevant default micro links are visible ? I have a feeling I have to solder a few back in....3692425244?profile=original

  • I just want to get this straight as well regarding the mapping of serial ports on the APM2 (V 2.4.1). Can someone confirm the following:

    Description; Label on Board; Physical position on PCB; Mapping in source code

    USB/FTDI; None; USB connector below SD IF;  FastSerialPort0(Serial):  #define xxx_PORT 0 

    GPS Port; UART1; Next to IN1; FastSerialPort1(Serial):  #define xxx_PORT 1 

    Telemetry Port (When USB not connected); UART0/2;  Next to OUT8; FastSerialPort3(Serial);  #define xxx_PORT 3 

    Telemetry Port (Hardwired); UART2; Side of board next to RESET; FastSerialPort3(Serial);  #define xxx_PORT 3

    Why would the telemetry port (either UART0/2 or UART2) not be named  a logical FastSerialPort2(Serial); #define xxx_PORT 2?  

  • Chris,

    UART0 is as shown, no need to change the wiki if the issue is not common. 3692406550?profile=original

  • 3D Robotics

    Muthanna,

    I'm not sure I'm following. Where is the UART0 that you're referring to? The images in the wiki refer to the standard setup, which is what I use.

    Maybe some boards shipped from the factory with a missing/broken microtrace for the UART selection? If so, we'll correct that. But I'm not understanding why the manual recommendations should change, since that's what thousands of people already use.

  • Chris,

    APM2.0 photo you just posted has Ver 2.4.1 on it, mine is Ver 2.4 (I bought it from 3DR almost one month ago); is there any difference related to our issue ??

  • Known issue in a number of threads. I have the same problem on 2 APM 2.0s. The workaround is to use the hardwired uart 0 on the long side of the board right next to the 2x3 row ICSP header. There is something up with the one listed in the directions as there is a jumper solder pad on the bottom of the APM to connect the port to either uart0 or 2. I have tried without succes to to find the right combination to get uart0 out of the port listed in the directions but jsut use the hardwired one for now.

This reply was deleted.

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