Xbee Help, values not transmitting

mhamen3 · 2012-11-27 17:20

Hi Guys,

I'm having trouble getting my xbees to communicate from prop to prop. I'm working on a remote control and I can't seem to get the signals from my controller to be read on my robot.

I've checked the obvious, each is receiving 3.3V, Dout is connected to the XB_Rx pin and Din is connected to the XB_Tx pin, and I've tested the xbees with the x-ctu software to make sure they are actually working.

Below is my code for the transmitter and receiver:

Transmitter

CON
   _clkmode = xtal1 + pll16x 
  _xinfreq = 5_000_000 


  cpin = 0
  dpin = 1
  spin = 2


  XB_Rx = 26
  XB_Tx = 27
  XB_Baud = 9600
  
VAR


   Long Sldr[6]
   Long Gmbl[6]


OBJ
  ADC   : "MCP3208"
  PST   : "Parallax Serial Terminal"
  XB    : "Xbee_Object_2"  


Pub Start 
XB.start(XB_Rx, XB_Tx, 0, XB_Baud) ' Initialize comms for XBee




  repeat
      Sldr[1] := ADC.average(0,10)
      Sldr[2] := ADC.average(1,10) 
      Sldr[3] := ADC.average(2,10)
      Gmbl[1] := ADC.average(3,10)
      Gmbl[2] := ADC.average(4,10)
      Gmbl[3] := ADC.average(5,10)
      Gmbl[4] := ADC.average(6,10)
      IF Gmbl[4] > 2500
        Gmbl[4] := 1
      ELSE
        Gmbl[4] := 0
  
      XB.Tx("!") ' Send start delimiter
      XB.Dec(Sldr[1])
      XB.CR
      XB.Dec(Sldr[2])
      XB.CR
      XB.Dec(Sldr[3])
      XB.CR
      XB.Dec(Gmbl[1])
      XB.CR
      XB.Dec(Gmbl[2])
      XB.CR
      XB.Dec(Gmbl[3])
      XB.CR
      XB.Dec(Gmbl[4])
      XB.CR

Receiver

CON
   _clkmode = xtal1 + pll16x 
  _xinfreq = 5_000_000 


  XB_Rx = 26
  XB_Tx = 27
  XB_Baud = 9600
  
  
VAR


   Long Sldr[6]
   Long Gmbl[6]


OBJ
  XB    : "Xbee_Object_2"
  PST   : "Parallax Serial Terminal"


Pub Go | DataIn
   XB.Start(XB_Rx,XB_Tx,0,XB_Baud)
   PST.start(115200)


   PST.str(string("Awaiting Data..."))

  Repeat
   DataIn := XB.Rx ' Accept incoming byte
   If DataIn == "!" ' If start delimiter
      DataIn := XB.RxDecTime(500) ' 
      if DataIn <> -1 ' If wasn't time out
        Sldr[1] := DataIn


      DataIn := XB.RxDecTime(500)
      if DataIn <> -1
        Sldr[2] := DataIn


      DataIn := XB.RxDecTime(500)
      if DataIn <> -1
        Sldr[3] := DataIn


      DataIn := XB.RxDecTime(500)
      if DataIn <> -1
        Gmbl[1] := DataIn


      DataIn := XB.RxDecTime(500)
      if DataIn <> -1
        Gmbl[2] := DataIn


      DataIn := XB.RxDecTime(500)
      if DataIn <> -1
        Gmbl[3] := DataIn


      DataIn := XB.RxDecTime(500)
      if DataIn <> -1
        Gmbl[4] := DataIn


 
      PST.str(string("   Sldr 1 ="))
      PST.dec(Sldr[1])




      PST.str(string("   Sldr 2 ="))
      PST.dec(Sldr[2])




      PST.str(string("   Sldr 3 ="))
      PST.dec(Sldr[3])


 
      PST.str(string("   Gmbl LR ="))
      PST.dec(Gmbl[1])


      PST.str(string("   Gmbl UD ="))
      PST.dec(Gmbl[2])


      PST.str(string("   Gmbl ROT ="))
      PST.dec(Gmbl[3])
        


      PST.str(string("   Gmbl Btn ="))
        IF Gmbl[4] == 1
                PST.str(string("ON"))
        ELSE
                PST.str(string("OFF"))


        PST.newline

So I'm just trying to get the values from my remote to be read on my receiver and printed to the PST.

Any help would be much appreciated

Thanks,
Marc

StephenMoore · 2012-11-28 20:14

Looks to me like your transmitter may be slamming the radio a bit hard. Try putting a waitcnt(clkfreq / 4 + cnt) in the loop to allow the UART to handle the data flow.

Also your receive loop will fall through on timeouts and may mess up your data sync. Just use xbee.rx instead and make sure you are actually sending data to get you out of the receive mode.

If the radios are working in XCTU then you have them set up fine.

Try transmitting from one prop to XCTU terminal as a check and from XCTU to the receiver prop as well.

Good luck.

sm

mhamen3 · 2012-11-29 06:22

Thanks Stephen, I appreciate the help.

mhamen3 · 2012-11-30 13:30

Don't know exactly why, but when I used Full duplex serial on the TX side instead of the xbee object, it worked.

Xbee Help, values not transmitting

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