Bonjour Steve!
Yup, I thought of that, same with PAUSEUS. I also use a button to shift in new data after I've sent +5V DC to one of the input pins on the 74HC166. Here's all my code, I even left in the indicator LEDs I've been using to display results:
INCLUDE "MODEDEFS.BAS" ' Serial I/O modes
ASM
LIST
INCLUDE 'M16F62X.INC' ; PM header
DEVICE PIC16F628, HS_OSC, WDT_OFF, PWRT_ON, MCLR_OFF, LVP_OFF, PROTECT_OFF
XALL
NOLIST
ENDASM
DEFINE OSC 20 ' Set oscillator speed
DEFINE SHIFT_PAUSEUS 3 ' Slow down SHIFT in/out commands by 3uSECS
CMCON = 7 ' Set PORT A pins to digital
SHFTIQ7 VAR PORTB.0 ' Input data
SHFTICP VAR PORTB.1 ' Input clock pulse
SHFTICE VAR PORTB.2 ' Input clock enable
SHFTIPE VAR PORTB.3 ' Input parallel enable
BUTTONI VAR PORTA.4 ' Input user entry
LED1 VAR PORTA.2 ' Bit active indicator
LED2 VAR PORTA.3 ' Loop indicator
LOOP VAR BYTE
DATAI VAR BIT[16]
HIBIT CON %1
HIBYTE CON 1
START: DATAI = 0 ' Initialize variables
LOOP = 0
GOSUB REQBUT ' Wait for user input
LOW SHFTIPE ' Initiate parallel load of bits
LOW SHFTICE
GOSUB CYCCLK
HIGH SHFTIPE ' Initiate serial shift of bits
LOW SHFTICE
GOSUB CYCCLK
HIGH SHFTICE ' Initiate hold of shift registers
SHIFTIN SHFTIQ7,_ ' Shift in bits from registers
SHFTICP,_
LSBPRE,_
[DATAI\16]
FOR LOOP = 0 TO 15 ' Check bits for a high bit
GOSUB BITNUM
IF DATAI = HIBIT THEN
GOSUB HIFND
ENDIF
NEXT LOOP
GOTO START ' Restart processing
FINISH: END ' Terminate processing
' SUB-ROUTINES
REQBUT: GOSUB FLASH ' Process user input
IF BUTTONI <> HIBYTE THEN GOTO REQBUT
RESUME
FLASH: HIGH LED1 ' Indicate waiting for user input
HIGH LED2
PAUSE 250
LOW LED1
LOW LED2
PAUSE 250
RETURN
CYCCLK: LOW SHFTICP ' Cycle clock pulse
HIGH SHFTICP
RESUME
BITNUM: HIGH LED2 ' Indicate bit number within string
PAUSE 250
LOW LED2
PAUSE 250
RETURN
HIFND: HIGH LED1 ' Indicate bit is high
PAUSE 250
LOW LED1
PAUSE 250
RETURN
If I jst connect the input pins to the PIC to GND, all the bits are 0, if I connect to +5V DC, all the bits are 1, which is what I expect. I'm stumped.
Robert
Bookmarks