Making the Ping Wireless

Tymkrs · 2012-06-29 01:06

I apologize as this seems to be along the same grain as the last four posts. But I decided to make an attempt at getting my Ping to be wireless by way of XBee (series 1) modules.

My remote node is a propboe with the xbee, and my base node is a propdemo board with an xbee (my second propboe decided to go bust on me):

Base Node Code:

CON  
  _clkmode = xtal1 + pll16x
  _xinfreq = 5_000_000


  ' Set pins and Baud rate for XBee comms
  XB_Rx     = 0    ' XBee DOUT
  XB_Tx     = 1    ' XBee DIN
  XB_Baud   = 9600 ' XBee Baud Rate


  ' Set pins and baud rate for PC comms
  PC_Rx     = 31
  PC_Tx     = 30
  PC_Baud   = 9600


  CR = 13
VAR
  long   Range
OBJ
   XB    : "XBee_Object_2"
   PC    : "XBee_Object_2" ' Using XBee object on PC side for more versatility


Pub  Start
  XB.Delay(2000)
  PC.str(string("Warming Up XBee..."))
  PC.start(PC_Rx, PC_Tx, 0, PC_Baud) ' Initialize comms for PC
  XB.start(XB_Rx, XB_Tx, 0, XB_Baud) ' Initialize comms for XBee


  repeat
      XB.Delay(100)                             ' Allow buffer
      XB.RxFlush                                ' Empty buffer
      GetReading                                ' Request Ping value
      XB.Delay(1000)                            ' 1 second delay


Pub GetReading
   XB.Tx("P")                                   ' Send P for Ping measurement
   Range := XB.RxDecTime(500)                   ' Accept returned data
   If Range == -1                               ' -1 means timeout
     PC.str(string("No Response"))
   else
     PC.str(string("Ping Reading", 32))
     PC.tx(Range)                              ' Display value
     PC.tx(13)

Remote Node Code:

CON  _clkmode = xtal1 + pll16x
  _xinfreq = 5_000_000


  ' Set pins and Baud rate for XBee comms
  XB_Rx     = 0    ' XBee DOUT
  XB_Tx     = 1    ' XBee DIN
  XB_Baud   = 9600 ' XBee Baud Rate


  CR = 13          ' Carriage Return
  Ping_Pin = 4


OBJ
   XB    : "XBee_Object_2"
   Ping  : "Ping"


VAR
  Long Range


Pub  Start | DataIn


  XB.start(XB_Rx, XB_Tx, 0, XB_Baud)       ' Initialize comms for XBee
  XB.RxFlush                               ' Ensure XBee buffer empty
  repeat
     DataIn := XB.Rx
       Case Range                                ' Wait for byte
          "P": DataIn := XB.RxDecTime(500)    ' If byte P, accept request
             if DataIn <> -1                 ' Ensure wasn't timeout
               Range := Ping.Inches(ping_pin)
               XB.DEC(Range)
               XB.CR

I feel like something's missing, and I know there is since the code doesn't want to work or let the XBees be recognized by X-CTU during a Test/Query. This was somewhat cobbled (noobie style) from the led/buzzer code in the XBee tutorial PDF. I'd love any suggestions...thanks!!!

Oh and the goal is to have the ping be on the remote node. Have the base node continously ping to get a Ping measurement back and displayed in either X-CTU or a serial terminal window. At this point I'll take either

.

Tymkrs · 2012-06-29 17:32

So I looked at the tutorial again and on page 61, there's a statement "Using the XBee is a great way to simply monitor your Remote node for robotics or sensor data." So I thought I'd start from scratch and try to use the Serial Pass Through Data and the Debug Data.

So the BASE Prop w/Xbee had the following "Serial Pass Through" code:

CON 
  _clkmode = xtal1 + pll16x 
  _xinfreq = 5_000_000 
  ' Set pins and Baud rate for XBee comms   
  XB_Rx     = 0    ' XBee DOUT 
  XB_Tx     = 1    ' XBee DIN 
  XB_Baud   = 9600 
  ' Set pins and baud rate for PC comms  
  PC_Rx     = 31   
  PC_Tx     = 30 
  PC_Baud   = 9600       
    
Var 
  long stack[50]                ' stack space for second cog 
                                                                        
OBJ 
  PC    : "FullDuplexSerial"   
  XB    : "FullDuplexSerial" 
Pub Start  
  PC.start(PC_Rx, PC_Tx, 0, PC_Baud) ' Initialize comms for PC   
  XB.start(XB_Rx, XB_Tx, 0, XB_Baud) ' Initialize comms for XBee   
  cognew(XB_to_PC,@stack)       ' Start cog for XBee--> PC comms 
  PC.rxFlush                    ' Empty buffer for data from PC 
  repeat                    
    XB.tx(PC.rx)                ' Accept data from PC and send to XBee 
        
Pub XB_to_PC 
  XB.rxFlush                    ' Empty buffer for data from XB 
  repeat                  
    PC.tx(XB.rx)                ' Accept data from XBee and send to PC

And then the REMOTE prop w/xbee had the following code:

CON   _clkmode = xtal1 + pll16x 
  _xinfreq = 5_000_000 
  
  XB_Rx     = 0    ' XBee DOUT 
  XB_Tx     = 1    ' XBee DIN 
  XB_Baud   = 9600 
  CR        = 13   ' Carriage Return value       
  Ping_Pin  = 4                                                                        
OBJ 
   XB    : "FullDuplexSerial"
   Ping  : "Ping"
Pub  Start | Counter, range 
XB.start(XB_Rx, XB_Tx, 0, XB_Baud) ' Initialize comms for XBee 
   
waitcnt(clkfreq + cnt)


 repeat
    range := ping.Inches(ping_pin)           ' Get range in inches           
    XB.str(string("Ping Measurement:"))      ' send string
    XB.dec(range)                            ' send decimal value
    XB.Tx(CR)                                ' send Carriage Return
    waitcnt (clkfreq/4 + cnt)

And when you use X-CTU to monitor the Ping Measurements on the Base Node's comport, you end up with this:

It's not as controlled as what I'd like it to be as the measurements just start as soon as everything's turned on, and ideally, I'd be able to incorporate a pushbutton into this. But, it's still wireless!

I also wanted to note that Test/Query did not work for either prop (strangely enough). But I guess that didn't stop things from working.

Making the Ping Wireless

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