4 Wire SPI with Shiftin/Shiftout ?

[CuriousOne]

Yes, I tried with mode 5 and it does not works, it also does not works with mode 4 or others.
MSSP or whatever it is, might be good, but are there direct support statements in PBP ?
And also, I already have pre-wired devices and they're meant to be in that way.

The code below does not works - it returns all 255.

;----[16F886 Hardware Configuration]--------------------------------------------
#CONFIG
cfg1 = _INTRC_OSC_NOCLKOUT    ; INTOSCIO oscillator: I/O function on RA6/OSC2/CLKOUT pin, I/O function on RA7/OSC1/CLKIN
cfg1&= _WDT_ON                ; WDT enabled
cfg1&= _PWRTE_OFF             ; PWRT disabled
cfg1&= _MCLRE_OFF             ; RE3/MCLR pin function is digital input, MCLR internally tied to VDD
cfg1&= _CP_OFF                ; Program memory code protection is disabled
cfg1&= _CPD_OFF               ; Data memory code protection is disabled
cfg1&= _BOR_OFF               ; BOR disabled
cfg1&= _IESO_ON               ; Internal/External Switchover mode is enabled
cfg1&= _FCMEN_ON              ; Fail-Safe Clock Monitor is enabled
cfg1&= _LVP_OFF               ; RB3 pin has digital I/O, HV on MCLR must be used for programming
cfg1&= _DEBUG_OFF             ; In-Circuit Debugger disabled, RB6/ICSPCLK and RB7/ICSPDAT are general purpose I/O pins
  __CONFIG _CONFIG1, cfg1


cfg2 = _BOR40V                ; Brown-out Reset set to 4.0V
cfg2&= _WRT_OFF               ; Write protection off
  __CONFIG _CONFIG2, cfg2


#ENDCONFIG




'chip configs
TRISA=%01000000  'SET A TO OUTPUT   1=input
TRISC=%00000000   'set half C for in/out
TRISB=%00000000   'set PortB to output
ANSELH=%00000000   ' ADC OFF B
ANSEL=%000000000 'configure PortA as digital except first 2
ADCON1=%10000000  'adc justify
OSCCON=%01110101  'SET FREQUENCY TO 8MHZ
WPUB=%00000000    'turn off Pullups
CM1CON0=0         'DISABLE COMPARATORS
CM2CON0=0         'SAME HERE


DEFINE OSC 8   
DEFINE ADC_BITS 10
DEFINE ADC_CLOCK 3
DEFINE ADC_SAMPLEUS 50
'lcd config
pause 10
' Set LCD Data port 
DEFINE LCD_DREG PORTC  
DEFINE LCD_DBIT 4  
DEFINE LCD_RSREG PORTB  
DEFINE LCD_RSBIT 0  
DEFINE LCD_EREG PORTB  
DEFINE LCD_EBIT 1  
DEFINE LCD_BITS 4  
DEFINE LCD_LINES 2  
DEFINE LCD_COMMANDUS 1500  
DEFINE LCD_DATAUS 44




SCLK	VAR	PORTB.5 'CLOCK
TC	VAR	PORTC.0 'TO CHIP - WRITE
FC	VAR	PORTC.6 'FROM CHIP - READ
RST	VAR	PORTB.4 'RESET
I VAR BYTE 'COUNTER VAR
X VAR BYTE 'TEMP VAR
FONT VAR BYTE [8] 'FONT ARRAY


Reader: 'Font reading outline
LOW RST         ' Ready for transfer
   Shiftout TC, SCLK, 5, [$03,$100,$00,$0] ' Send write command, set start offset 
For I=0 to 255 'read 8 bytes of data
   Shiftin FC, SCLK, 5, [x]
LCDOUT $fE, $C0, DEC I,32, DEC X
Pause 200
next
HIGH RST        ' Reset IC
GOTO READER

[HenrikOlsson]

I'd try mode 5 for SHIFTOUT and mode 6 for SHIFTIN.
I would also add some code to make sure #CS is high for a while during startup. Then I would add a scope or logic analyzer to verify that what you think is happening is actually happening at the hardware level.

[richard]

I'd try mode 5 for SHIFTOUT and mode 6 for SHIFTIN.

You can learn something everyday
that seems to work with spi 25aa1024 eeprom

[CuriousOne]

Shiftout 6 changed nothing, so will hook up scope in logic analyzer mode and report.

[CuriousOne]

Hooked scope to pins.
There is series of pulses on SCLK and RST gets high and low as specified.
However, there is no activity on serial input/output lines.
To check the wiring, I wrote this simple code:

krd:
high sclk
high tc
high rst
high fc
pauseus 500
low sclk
low tc
low rst
low fc
pauseus 500
goto krd

And it works fine - I can see square pulses with scope on each pin, so there are no wiring issues.

Any ideas?

[HenrikOlsson]

One issue might be the fact that you have LCD datapins overlapping at least one of the pins that you're using with SHIFTIN/SHIFTOUT.
This code does not match comment: TRISC=%00000000 'set half C for in/out.
Also, note that my suggestion was to try mode 6 on SHIFTIN - not SHIFTOUT. Not that it would make any difference untill SHIFTOUT is outputting data.

[richard]

not to mention. a 32bit address attempt ?

Reader: 'Font reading outline
LOW RST ' Ready for transfer
Shiftout TC, SCLK, 5, [$03,$100,$00,$0] ' Send write command, set start offset
For I=0 to 255 'read 8 bytes of data
Shiftin FC, SCLK, 5, [x]
LCDOUT $fE, $C0, DEC I,32, DEC X
Pause 200
next

5.75 SHIFTOUT
SHIFTOUT DataPin, ClockPin, Mode, [Var{\Bits}...]
Synchronously shift out Var on ClockPin and DataPin. ClockPin and DataPin may be a constant, 0-15, or a variable that contains a number 0-15 (e.g. B0) or a pin name (e.g. PORTA.0).
SHIFTOUT is a software-based command and does not require that the target device have synchronous serial capability. The ClockPin and DataPin parameters may be set to any digital I/O pins, and may be different in different commands within the same program.
\Bits optionally specifies the number of bits to be shifted out. If it is not specified, 8 bits are shifted out, independent of the variable type. The Bits shifted out are always the low order bits, regardless of the Mode used, LSB or MSB. Up to 32 Bits can be shifted out of a single (long) variable. If more than 32 Bits are required, multiple variables or constants may be included between the square brackets.