pulsout pulsin on same pin - timing?

[vacpress]

Hello. I am trying to use Parallax ultrasonic Sensor PN 28015

For some reason, I cannot get the code to work. I have searched for quite a bit and found examples of people using similar code with the same and similar(devantech sf04) devices.

I am using a PIC16f887 at 8mhz external oscillator. This should give a pulsout cycle of 5us.

In the attached image you can see the interface info for the sonar sensor. It appears that I send a pulse of 5us, wait ~750us then read back a result upto 18.5ms. Any idea if my current code fulfills these goals?

I have hooked the devices upto an o-scope and verified their operation. I can see the return pulse begin 750us after the end of a trigger pulse. I read in the pic basic docs that the pulsin waits 65555 cycles for a pulse to time. Is this all working with my current code?

When I trigger the device, the sensors LED lights, but I always get back a 0.

Here is my code.

DEFINE OSC 8                 ' Set oscillator to 8mhz
DEFINE DEBUG_REG	PORTC    ' Set PORTC as debug serial out port
DEFINE DEBUG_BIT	6        ' PORTC.6 Set Debug-Out pin bit
DEFINE DEBUG_BAUD	9600    ' Set Debug baud rate
DEFINE DEBUG_MODE	0     	' Set Debug mode: 0 = true, 1 = inverted

TRISB.0 = 0                 ' setup port b.0 as output initially
ANSEL = 0                   ' disable all AD convertors

' -----[ I/O Definitions ]-------------------------------------------------
Ping            var     PORTB.0

' -----[ Variables & Constants]--------------------------------------------
rawDist         VAR     Word                    ' raw measurement
Trigger         CON     2                      ' trigger pulse = 10 uS       (at 8mhz this is 5us per pulsout)
IsHigh          CON     1                       ' for PULSOUT
IsLow           CON     0
' -----[ Initialization ]--------------------------------------------------
reset:
PAUSE 100
DEBUG      "Parallax Ping Sonar Test  ", 10
 
 
' -----[ Program Code ]----------------------------------------------------
Main:

   if PORTA.0 = 1 then                          ' wait for keypress
    GOSUB Get_Sonar                             ' get sensor value
       debug DEC rawDist                        ' output raw distance data
      PAUSE 100           
   endif
 goto main    ' loop forever
END
  
  
' -----[ Subroutines ]-----------------------------------------------------
Get_Sonar:
'high 4
low ping                                     ' make trigger 0-1-0
  PULSOUT Ping, Trigger                      ' activate sensor by sending 10us pulse

  PULSIN  Ping, 1, rawDist                   ' measure echo pulse

  
  RETURN