PIC or xbee times out after Tx 504 bytes

[archendekta]

'###############################################
'#
'# program to test Tx & Rx API packets on 
'#  xb24 series 1 units. 
'#
'# host mcu's=  pic16f88
'#
'###############################################


'---[set fuses]---------------------------------

'Program Configuration Register 1
@ __CONFIG    _CONFIG1,  _HS_OSC & _DEBUG_OFF & _WDT_ON & _LVP_OFF & _CP_ALL & _CPD_ON & _BODEN_ON & _MCLR_ON & _PWRTE_ON & _WRT_PROTECT_OFF

;Program Configuration Register 2
@ __CONFIG    _CONFIG2, _IESO_OFF & _FCMEN_OFF



'---[includes----]-------------------------------

INCLUDE "bs2defs.bas"


'---[debug defines]-------------------------------

DEFINE DEBUG_REG PORTA
DEFINE DEBUG_BIT 2
DEFINE DEBUG_BAUD 9600
DEFINE DEBUG_MODE 1

'---[defines]--------------------------------------

DEFINE  OSC 8

'DEFINE HSER_RCSTA 90h 
DEFINE HSER_RCSTA 92h ' Enable serial ports Tx & Rx, sets SPEN & CREN & OERR
DEFINE HSER_TXSTA 24h ' Enable Tx HS, TXEN=1 & BRGH=1
DEFINE HSER_BAUD 9600 ' set baud and compiler will auto calc HSER_SPBRG
DEFINE HSER_CLROERR 1 ' Clear overflow automatically


ANSEL=0  
ADCON0=0
ADCON1=7
CMCON=7

'---[contants]---------------------------------------

LF            CON 10
CR            CON 13
MAX_DATA_LEN  CON 12


'-----------------------------------------------------------------------

BLINK_PA1  VAR portA.1    
BLINK_PB1  VAR portB.1    'to show sending serial data

TX_APIPacket  VAR byte[14]
Counter       VAR byte
Checksum      VAR byte
Ndx           VAR byte




'-----------------------------------------------------------------------
       
INIT:
  Clear
  gosub FILL_API_PACKET 



MAIN:
   FOR counter=0 to 35
      gosub sub_Test_Tx_API_Frame
   next counter
   goto MAIN



sub_Test_Tx_API_Frame:
    gosub sub_CALC_Checksum

    'send debug to realterm window
    Debug "TX= ",str TX_APIPacket\13," ", hex checksum, " [Cnt: ",dec counter,CR
 
    hserout [str TX_APIPacket\13, checksum]  
    gosub sub_BLINK_PB1  'show pic is alive
    pause 500
RETURN



FILL_API_PACKET:
   TX_APIPacket(0)=$7E  
   TX_APIPacket(1)=$00   
   TX_APIPacket(2)=$0A   
   TX_APIPacket(3)=$01   
   TX_APIPacket(4)=$01    'API frame ID
   TX_APIPacket(5)=$50    'DL addr
   TX_APIPacket(6)=$01    'DL addr
   TX_APIPacket(7)=$00    'option
   TX_APIPacket(8)=$48    'H
   TX_APIPacket(9)=$65    'E
   TX_APIPacket(10)=$6c   'L
   TX_APIPacket(11)=$6c   'L  
   TX_APIPacket(12)=$6f   'O
RETURN   


sub_CALC_Checksum:
    Checksum = 0
    for Ndx = 3 to MAX_DATA_LEN
       Checksum = Checksum + TX_APIPacket(Ndx)
    next 
    Checksum =  $FF & Checksum  'remove values > 1 byte
    Checksum = $FF - Checksum   '2's compliment
RETURN


sub_BLINK_PA1:
  High BLINK_PA1
  pause 200
  low BLINK_PA1
  PAUSE 200
RETURN


sub_BLINK_PB1: 
  High BLINK_PB1
  pause 200
  low BLINK_PB1
  PAUSE 200
RETURN


END

mcu=pic16f88
xbee=xb24

i'm sending a string then checksum from the host pic16f88 to a xbee and that xbee sends it to another xbee. somewhere around 34-35 iterations for a total of 504 bytes the xbee's stop sending/recieving.

the pic is still sending the string out as i can see this with a LCD
connected to the Tx pin on the sending host.

Now, i can use two xbib dev boards connected to my computer with one of the xbee's on each and send the same API packet with no issues.

so i'm leaning towards the problem is my pic16f88 or my program/fuses or both.

any thoughts on why this is happening?

thx
archendekta

[archendekta]

finally got the setup to work.

can't say for sure what exactly what was causing the problem. reflashed all the xbee's to their default and reset a few parameters and all is working fine.

code was fine and the pic's were fine.

[Ioannis]

From a very preliminary test I did, the receiver of the XBees is very susceptible to saturation. I had to move the modules 10-15 meters away to work properly. I know this seems irrelevant ot your case but just keep it in mind.

Ioannis

P.S. Are you going to make a ZigBee network?

[archendekta]

the distance factor could have been an issue and one to keep in mind. thanks.

i have the xbp24-zb's for another project for a ZB network.

this current one is using the "802.15.4 series I" xbee's.

i wonder if there is a config parameter that helps with the saturation issue for short distances? would you know?

[Ioannis]

Just drop the RF power to the minimum. But ifdistance is less that 5 meters the receivers are saturated again.

Ioannis

[archendekta]

0= -10dBm
1= -6dBm
2= -4dBM
3= -2dBm
4= 0dBm

so with these 802.15.4 series I, lowest would be -10dBm, yes?

good to know, thx