SHIFTOUT with PIC12F675?

[zorgloub]

Hello to the Community.
Is the Shiftout command possible for a PIC12F675?
I ride a program using this command but my logic analyzer does not show me any pulse of Data and Clock!
Thanks.

[zorgloub]

Here is the test program...

'************************************************************************
'   Programme: Shiftout Test PBP   (c)Roger LEGAT 07-2023
'   RX Tester---> PIC 12F675
' PicBasicPro Compiler V:2.40   ---> 393 Words used
'************************************************************************
'*** PIC Pinouts/Specifications
'------------------------------------
'            PIC 12F675
'                   __ __
'           Vcc +|  U  |- Gnd
'        GPIO.5 x|     |< GPIO.0
'        GPIO.4 >|     |> GPIO.1 _DIO
'        GPIO.3 >|     |> GPIO.2 _CLK
'                    -----

@ Device Pic12F675, intrc_osc, wdt_off, pwrt_on, mclr_off, protect_off

DEFINE OSC 4    ' Pulsin/Pulsout Resolution    =10µsec    => 1ms=100
'   (Pulse Value of 1msec x10 =1000)    [x10]
'  Pause =1msec => 1msec=1    1sec=1000

Include "modedefs.bas"   ;for shiftout command

CMCON  = 7   'Comparator Off
ANSEL  = 0   'Set Port to Digital i/o         
ADCON0 = 0   'All ADC Off
 
Asm
 bsf STATUS      ;Bank 1
 call 3FFh       ;Get the CAL value from 3FF addresse YOU WRITE BEFORE !
 movwf OSCCAL    ;Calibrate
 bcf STATUS, RP0 ;Bank 0
Endasm

'*** In/Out pins ..................................................
 Output 1 : _DIO var GPIO.1
 Output 2 : _CLK var GPIO.2

'*** Variables/Constants
  Pack       VAR BYTE        ;Byte to send
  
 '=== MAIN PROGRAM =====================================================

 Pack = 255

MainLoop:
 
   Shiftout _DIO,_CLK,LSBFIRST,[Pack\8] 'Send Byte
   pause 100

Goto MainLoop


;=========== END OF PBP =================================================

[Ioannis]

Maybe it is better to define the output register more convenitional.

Try

TRISIO = 0

DIO VAR GPIO.1
CLK VAR GPIO.2

and report back how is doing.

Ioannis

[zorgloub]

Hi,

I'm trying to understand and learn:

What might be the consequences if I set my ports as follows:

Dio var GPIO.0
or
Symbol Dio = GPIO.0

Does this make a difference to the way the program is processed?

Thanks

[Ioannis]

Originally the problem I think was this syntax:

'*** In/Out pins ..................................................
Output 1 : _DIO var GPIO.1
Output 2 : _CLK var GPIO.2

I do not see how this can compile.

Ioannis

[zorgloub]

Hello,
And yet the compiler didn't give any errors!?

I'm going to keep your suggested syntax anyway.

Concerning my problem with the Shiftout command, I note that a problem existed with this command for the Picaxe 08M2 (which is in fact a PIC12F1840).
The Shiftout command was not possible for this Picaxe and it was necessary to create a small routine explained in the Picaxe manual.

Before continuing my tests, I wondered if such a problem could also be encountered with my Pic12F675... ?

[Ioannis]

In PBP I never encountered any problems with SHIFTout or SHIFTin commands.

I pressume you will not have too.

Ioannis

[Ioannis]

Hello,
And yet the compiler didn't give any errors!?

Why would give any error?

output 1 or output 2 are valid commands that make pin 1 or pin2 output.

And then you define the aliases _DIO var GPIO.1 etc.

But did not defined the TRIS register.

Ioannis

[zorgloub]

Why would give any error?

But did not defined the TRIS register.

Ioannis

Isn't using the input or output commands for the ports used is not enough or does it work?

[Ioannis]

Yes but you defined wrong. For example _DIO var GPIO.1 is not the same as DIO var GPIO.1

Ioannis

[zorgloub]

Ah?
This unnderscore character has an influence for PBP?
I usually used this character to identify my entries or outputs on the MCU!

[zorgloub]

To come back to my original question about the SHIFTOUT command, here's the program I'm trying to run.
Unfortunately, I've noticed that the SHIFTOUT command doesn't produce any signals on the SDA and SCK output ports!
Any idea why?

'*****************************************************************
'*  Name     : Pulsin to TM1637.PBP                              *
'*  Author   : RGL                                               *
'*  Date     : 01/08/2023                                        *
'*  Version  : 1.0                                               *
'*  Compiler : PBPro 2.6                                        *
'*  Notes    : 415 words used                                    *
'*                                                               *
'*                                                               *
'*****************************************************************


'*** PIC Pinouts/Specifications
'------------------------------------
'             PIC 12F675
'                 __ __
'           Vcc +|  U  |- Gnd
'        GPio.5  |     |  GPio.0
'  Pulse GPio.4 >|     |> GPio.1 SDA (Data)
'        GPio.3  |     |> GPio.2 SCK (Clock)
'                 -----

@ Device Pic12F675, intrc_osc, wdt_off, pwrt_on, mclr_off, protect_off

'DEFINE OSC 4    ' Pulsin/Pulsout Resolution    =10µsec    => 1ms=100   DEFAULT VALUE
'   (Pulse Value of 1msec x10 =1000)    [x10]
'  Pause =1msec => 1msec=1    1sec=1000

Include "modedefs.bas"

CMCON  = 7   'Comparator Off
ANSEL  = 0   'Set Port to Digital i/o         
ADCON0 = 0   'All ADC Off

'OSCCAL = $4C (344C placed manually in the hex file at 3FF address)              
 
Asm
 ;bsf STATUS      ;Bank 1
 call 3FFh       ;Get the CAL value from 3FF addresse YOU WRITE BEFORE !
 movwf OSCCAL    ;Calibrate
 ;bcf STATUS, RP0 ;Bank 0
Endasm

'*** In/Out pins ..................................................

 TRISIO = %010000    'GPIO.4 Input=1.  All other Output=0

 SDA    Var GPIO.0    'Serial Data pin
 SCK    Var GPIO.1    'Serial Clock pin
 Pulse   Var GPIO.4   'Pulsin pin


'*** Variables/Constants

 CHR1 VAR BYTE             ;4 Byte to send
 CHR2 var Byte
 CHR3 var Byte
 CHR4 var Byte

 Value VAR WORD        ;Average Pulsin Value to display
 Measure VAR word        ;Intermediate and successives readings

 i  VAR BYTE        ;Working variable (20 successive measurements)


' TM1637 Commands
'-------------------
 ;CMD1 CON $40       'CMD1=$40 Write command Auto-increment Mode (Default Mode)
 CMD2 CON $C0       'CMD2=$C0 Start 1st digit position(left most = 1st digit)
 CMD3 CON $8C       'CMD3=$8A is the end command that turns the display ON and sets brightness to 69%

  
; Definition of the 10 characters in the EEPROM : 0-9 +Blank
; (Eeprom Starting address at 0)

; EEPROM(0   1   2   3   4   5   6   7   8   9   10 ) Pos10 = Blank
DATA @0,$3F,$06,$5B,$4F,$66,$6D,$7D,$07,$7F,$6F,$00 ; Write to Eeprom
    
'=== INIT TM1637 =====================================================

Gosub StartSeq
 SHIFTOUT SDA, SCK, 0, [CMD3]      'SHIFTOUT brightness
Gosub AckSeq 
gosub StopSeq

'=== MAIN PROGRAM =====================================================
MainLoop:
 Value = 0 : Measure = 0 'Initialize Value and Measure

  For i=1 to 20 '20 successive measurements for stabilisation of the display
    Pulsin Pulse,1,Measure
    Value = Value + Measure
  Next
  
  Value = Value /20                     ;Average PULSIN value
  Value = Value * 10                    ;Conversion to uS @4Mhz

;  Decomposition Method:
; ------------------------
   CHR1 = Value / 1000
     If CHR1 = 0 then
      CHR1 = 10 'Blank Char.
     Else
      CHR1 = CHR1+$80 '+Decimal point
     Endif

   CHR2 = Value / 100 // 10
   CHR3 = Value / 10 // 10
   CHR4 = Value // 10


'This sequence outputs now all 4 characters to the Display

Gosub StartSeq   'SHIFTOUT Mode 0 - LSB First, Clock normally low
    SHIFTOUT SDA, SCK, 0, [CMD2]    '1st Digit Adrress
 Gosub AckSeq
    

    SHIFTOUT SDA, SCK, 0, [CHR1]    '1st Digit value
  Gosub AckSeq

    SHIFTOUT SDA, SCK, 0, [CHR2]    '2e Digit value
  Gosub AckSeq

    SHIFTOUT SDA, SCK, 0, [CHR3]    '3e Digit value
  Gosub AckSeq

    SHIFTOUT SDA, SCK, 0, [CHR4]    '4e Digit value
  Gosub AckSeq

Gosub StopSeq

Goto MainLoop 

'====================================================================
'=============    SUBROUTINES    ====================================
'====================================================================

StartSeq:
 High SCK
 High SDA
 Low SDA
Return
;--------------------------

ACKSeq:
 Low SCK
 High SCK
 Low SCK
Return
;--------------------------

StopSeq:
 Low SCK
 Low SDA
 High SCK
 High SDA
Return

'===============  END OF PBP PROGRAMME =========================================================