Pulse Capture and byte building

Hi All,

I'm at a loss as why this is only making one pass through, any ideas?
I'm sending it a long (~100uS) or short (~50uS) pulse on RB.0 (INT) and it will grab the timer value for the appropriate length pulse.
That part is doing fine. Problem is that it will only make one pass, and then nothing. By one pass, I mean it will INT and start the timer, and on the next INT, it will grab the timer value and report it both on the LCD and out serially. The REM'd code is my attempt to build a byte from the captured bits, but so far, I can't get past single captures.

Code:

<html> <head></head> <body><pre><code>'**************************************************************** '* Name : PulseGrab.BAS * '* Author : boroko * '* Notice : Copyright (c) 2009 Controlled Surroundings Inc. * '* : All Rights Reserved * '* Date : 7/19/2009 * '* Version : 1.0 * '* Notes : testing on a 16F877A @ 20mHz on Lab-X1 * '* : Does one capture and displays, but no more. * '* : it DOES differentiate the pulse length '**************************************************************** ' Test bed to build pulse length receiver code. ' Short or long pulse on RB.0 ~ 50uS and ~100uS for "1" and "0" ' Display on a LCD and Transmit to test. INCLUDE "AllDigital.pbp" INCLUDE "DT_INTS-14.bas" ' Base Interrupt System INCLUDE "ReEnterPBP.bas" ' Include if using PBP interrupts DEFINE OSC 20 DEFINE LCD_DREG PORTD DEFINE LCD_DBIT 4 DEFINE LCD_RSREG PORTE DEFINE LCD_RSBIT 0 DEFINE LCD_EREG PORTE DEFINE LCD_EBIT 1 DEFINE HSER_RCSTA 90h ' enable serial port, %10010000 DEFINE HSER_TXSTA 24h ' enable transmit, BRGH hi, %00100100 DEFINE HSER_BAUD 19200 ' set baudrate to 19200 DEFINE HSER_CLOERR 1 ' automatic clear overrun error T1CON = %00001000 'TMR1 1:1 PS, Osc En, Int Clk, off to start ' returning 259 for short and 767 for long pulse @ 1:1 Time VAR WORD CntState VAR BIT LCDOUT $fe, 1 'blank flash to see if LCD updated PAUSE 100 LCDOUT $fe, 1, "PulseGrab SubTest" HSEROUT ["PulseGrab SubTest",13] PAUSE 500 LCDOUT $FE,1 '********************************************************* ASM INT_LIST macro ; IntSource, Label, Type, ResetFlag? INT_Handler INT_INT, _pulse, PBP, no endm INT_CREATE ; Creates the interrupt processor INT_ENABLE INT_INT ; enable external (INT) interrupts ENDASM '***************************************************************** Main: PAUSE 10 ' if (Time >230)&&(time < 280) then ' short pulse (1) received ' PulseIn = 1 ' maybe change window to improve ' gosub CharBuild ' save the character ' endif ' if (Time >750)&&(time < 800) then ' long pulse (0) received ' PulseIn = 0 ' maybe change window to improve ' gosub CharBuild ' save the character ' endif ' else ' PulseIn = 8 ' If nothing else, then no data ' ADD counter HERE to allow for a small gap before dumping ' charcnt = 0 ' Dump the counter and ' char = 0 ' dump the character received ' endif GOTO Main ''*************************************************************** ' INT Handler '****** Pulse capture using External Interrupt courtesy of DT ***************** pulse: IF INTCON.1=1 THEN ' External Interrupt happened IF CntState=0 THEN ' T1CON.0=1 ' Enable Timer OPTION_REG.6 = 0 ' Next trigger is Falling edge INTCON.1=0 ' Reset ExtInt Flag CntState =1 ELSE Time.LowByte = TMR1L ' Store the captured value in period variable Time.HighByte = TMR1H T1CON.0=0 ' Timer is OFF INTCON.4=0 ' ExtInt is OFF TMR1L=0 ' Reset Timer TMR1H=0 ' Remember Timer is OFF INTCON.1=0 ' Reset ExtInt Flag OPTION_REG.6 = 1 ' Next trigger is Rising edge CntState=0 LCDOUT $fe, 1, "Int" ' Show that we had an Interrupt LCDOUT $fe,$c0,"time ",#Time HSEROUT ["Int",13,10] HSEROUT [#Time,13] ENDIF ENDIF @ INT_RETURN '*************************************************************** ' Subs '****************************************************************** 'CharBuild: ' char.0 = PulseIn ' Put the pulse value in bit 0 ' Char = Char <<1 ' rotate RX bit into byte ' CharCnt = CharCnt+1 ' increment counter to track fill ' if CharCnt = 7 then ' RX byte is filled ' RXbyte = Char ' valid Comm byte received ' Lcdout $fe, 1, "RXbyte= ",RXbyte ' Show what we got ' hserout ["RXbyte= ",#RXbyte,13,10] ' transmit what we got ' endif 'return 'ACprog: ' look for lost power programming ' Lcdout $fe, 1, "AC in" ' Show that we dropped into "AC" ' hserout ["AC in",13,10] ' ' add test to gather data 'return END </code></pre></body> </html>

To give proper credit, this is based on one of Darrel's suggestions in another thread concerning pulse timing.

Any suggestions?
Thanks
Bo

Because you turn OFF the interrupts after the the first sample??

Code:

INTCON.4=0 ' ExtInt is OFF

Thanks

NOTE TO SELF: Sleep is a good thing.

It took me a moment to see it even after you pointed it out. I kept "seeing" it without realizing that it wasn't getting turned back on.

Thanks
Mark