confusion with the CD74HC165 8 bit register

[lerameur]

Hi Dave, I can do that, maybe tomorrow, Its only using three ports in my Pic16F887, how hard can it be. I tried to switch to PORTD:
Clock var PORTD.0 'CP
Load var PORTD.1 'PL
Data_1 var PORTD.2 'Q7 out
But no luck either Maybe the CD4014BE will be easier ??

ken

[mackrackit]

How is the shift register connected? Inputs pulled high/low, power,etc.

[lerameur]

well pin 16 is on 5V
pin 1 in D1
Pin 2 in D0
pin 9 is the data
8 in ground CE is ground, and the other 8 input pin some I have on 5v and some on ground .

K

[mackrackit]

Try pin 7 for the data line to the pic.

[mackrackit]

And go back to toggle-ing the load line.

[lerameur]

I will do it tonight, I think this is the inverted output

[falingtrea]

Simple explaination based on truth table:

While PL is low, anything that happens on the CP, CE and DS pins is ignored, levels on pins D0-D6 are saved into the internal shift registers, and D7 is saved into the shift register and output on Q7. So PL has to be low at some point in order to load the levels from the D0-D7 pins into the registers

When PL transitions from low to high, the last levels on D0-D7 are latched into the shift registers.

While PL is high, The CP, CE and DS pins start working and anything that happens on the D0-D7 pins is ignored. As long as the CE pin is low, clock pulses on the CP pin will serially shift data though the registers, and then out of the part on the Q7 and (Q7not) pins. The DS pin feeds into the first register and can be used to connect multiple HC165 parts together in a longer chain.

[mackrackit]

I think I see some of the problem, sorry I missed it earlier.

ANSELH = 0
should be
ANSEL = 0

And I just tried this on my simulator (bread board) to see if anything else was missing.

Change the PIC ports to match your setup.

'74HC165 CONNECTIONS
    'VSS = PIN #8 AND PIN# 15
    'VDD = PIN #16
    'No Connect = PIN #9 AND PIN# 10
    Clock   VAR PORTF.6   'PIN #2 74HC165
    Load    VAR PORTF.7   'PIN #1 74HC165
    Data_1  VAR PORTF.5   'PIN #7 74HC165
    KEYS    VAR BYTE
    HIGH    Load

    READ_KEYS:
    PULSOUT Load,1
    SHIFTIN Data_1,Clock,0,[KEYS]
    PAUSE 100
    LCDOUT $FE,1,"KEYS= ",BIN8 KEYS
    GOTO READ_KEYS