Thermo 7 segments - little problem

[fratello]

I try to use Mr.Darrel "DT_INTS-14.bas" to make another variant of my termometer using 4x7 segments LED, like this :

@ __config _INTOSC_OSC_NOCLKOUT & _WDT_ON & _MCLRE_ON

DEFINE OSC 4
CMCON        = 7
VRCON     = 0
INTCON    = 0
DQ        VAR PORTA.4
CLEAR

SEGDEF    VAR BYTE[3]
Value     VAR WORD
Idx       VAR BYTE
Temp      VAR BYTE
digitloop VAR BYTE
Blanking  VAR BIT

Temperature     Var     Word
TempC           Var     Word
I               Var     Byte
Sign            Var     Word
Float           Var     Word
V                Var     Word           
Dummy           Var     Byte
Busy            Var     Bit


DS18B20_12bit   CON %01111111       ' 750ms,   0.0625°C 

TrisB=0                    ' Make PortB outputs
TrisA.0=0:TrisA.1=0:TrisA.2=0        ' Make only the specific bits of PortA outputs                    
TrisA.3=0:TrisA.4=1
PortA=0:PortB=0                     ' Clear PortB and PortA


INCLUDE "DT_INTS-14.bas" ' Base Interrupt System
INCLUDE "ReEnterPBP.bas" ' Include if using PBP interrupts

ASM
INT_LIST macro ; IntSource, Label, Type, ResetFlag?
    INT_Handler TMR1_INT, _DISP, PBP, yes
  endm
  INT_CREATE ; Creates the interrupt processor
ENDASM

TRISA = 0
TRISB = 0

@ INT_ENABLE TMR1_INT ; enable Timer 1 interrupts
T1CON = $1 

' Init Sensor 1
 OWOUT DQ, 1, [$CC, $4E, 0, 0, DS18B20_12bit]
 OWOut DQ, 1, [$CC, $48]                   ' Start temperature conversion
 OWOut DQ, 1, [$CC, $B8] 
 OWOut DQ, 1, [$CC, $BE] 
 Pause 50
 OWIn DQ, 2, [temperature.byte0, temperature.byte1]

Main:
' Start temp.conv.Sensor1
 OWOut DQ, 1, [$CC, $44] 
 OWOut DQ, 1, [$CC, $BE]
 OWIn DQ, 2, [temperature.byte0, temperature.byte1]  

If Temperature.15 then       
  Temperature= ~Temperature +1
  Sign  = 1
Endif
 
Dummy = 625 * Temperature
TempC = DIV32 10 
TempC = (Temperature & $7FF) >> 4
Float = ((Temperature.Lowbyte & $0F ) * 25 )>>2
Temperature = TempC*100 + Float

If Sign=1 then
  V= 10000 - Temperature            
else
  V= 10000 + Temperature
EndIf

If V >= 10000 then                  
  Temperature=V-10000
  sign = " "                   
else                                   
  Temperature=10000-V                 
  sign = "-"
EndIf

 FOR Value = 0 TO 9999
    GOSUB SetDisp
   PAUSE 500
 NEXT Value
GOTO Main

'---[Set 7-seg patterns to WORD value]------------------------------------------
SetDisp:
  Blanking = 1
  FOR Idx = 3 to 0 STEP -1
    Temp = Value DIG Idx
    IF (Blanking AND Temp != 0) OR Idx = 0 THEN Blanking = 0
    IF Blanking THEN
      Temp = 0
    ELSE
      LookUp Temp,[132,175,193,137,170,152,144,143,128,136,210,251],Temp
    ENDIF
    SEGDEF(Idx) = Temp
  NEXT Idx
RETURN


'---[TMR1 - interrupt handler]--------------------------------------------------
DISP:
  T1CON.0 = 0                ; stop timer
  TMR1H = %11111100
  TMR1L = %00011111
  T1CON.0 = 1                ; restart timer

  PORTA = %1111              ; turn off all digits to prevent ghosting
  PORTB = SEGDEF(digitloop)  ; put segment pattern to pin
  PORTA = ~(DCD digitloop)   ; turn on the digit

  digitloop = digitloop + 1
  IF digitloop = 4 then digitloop = 0
@ INT_RETURN

...but where I must put the value of temperature ?! Any advice, please ? Thanks !

[fratello]

I try something like this

 FOR x = 0 TO 9999
 value=temperature
    GOSUB SetDisp
   PAUSE 500
 NEXT x
GOTO Main

but without results ... Any thought ?

[fratello]

I try to revive this topic ...
I found here (http://vnnik71.narod.ru/termo_ds18b20.html) schematic and hex file (even source code...) for an thermometer... It works absolutely great ! NO FLICKERING despite the absence of external quartz/HS oscillator !
How is made ?! I have no ideea ...
BUT ... in PBP this can be done ?!? I gave up to many LED display projects, because of this issue - annoying flickering ...
Know somebody a GOOD method to get a stable, sharp display ? Thanks in advance !

[AvionicsMaster1]

Although I can't open the sight I have a few questions. What is it you're trying to do? Improve upon project posted here or start from scratch?

What is the range of temperature you want to display?

What displays do you want to use? If flickering is a problem you could use a faster update rate but the display will only be as good as the quality of the display. I agree 7 segment LEDs are a dime a dozen but some are better than others. Although if you want large displays you may not be able to update them but will need to turn them on the whole time using FETs or transistors.

What is it ultimately you'd like to see from this project?

[fratello]

Thanks for reply !
So ... using as hardware - 16F628A @ 4 MHz and LED display KW4-311AVA, I built one termometer, using DS18B20, with different variants of software (presented in this topic). All my variants have this issue - display flickering, more or less, but present.
The hardware from the link posted above use same hardware, 16F628 @ 4 Mhz and same display. BUT ... no flickering ! The display look sharp and bright.
So ... I intend to build an termometer, using same hardware, but flicker-free ! And, despite searching this forum, I could not find any convenient version to apply.
This is why I asked for help ! Thanks in advance !

[fratello]

Tried a "variation" of code from post #20 :

;                        Termo LED 7 seg 
'======================================================================================

@ DEVICE pic16F628A, intOSC_osc_noclkout, WDT_OFF, PWRT_ON, MCLR_OFF, LVP_OFF, CPD_OFF


INCLUDE "DT_INTS-14.bas" ' Base Interrupt System
INCLUDE "ReEnterPBP.bas" ' Include if using PBP interrupts

DEFINE OSC 4
CMCON	= 7
VRCON 	= 0
INTCON 	= 0

                                
    Common_4   	VAR PORTA.1
    Common_3   	VAR PORTA.0
    Common_2   	VAR PORTA.7
    Common_1   	VAR PORTA.6   
    DQ            VAR PORTA.4
    DP            VAR PORTB.2

Temp   	    Var     Byte
Temperature     Var     Word
TempC           Var     Word
I               Var     Byte
Sign            Var     Word
Float           Var     Word
V		    Var     Word		   
Dummy           Var     Byte
Busy		    Var     Bit
    DIGIT_0     VAR 	BYTE
    DIGIT_1     VAR 	BYTE
    DIGIT_2     VAR 	BYTE
    DIGIT_3     VAR 	BYTE
digit		    Var 	BYTE

DS18B20_12bit 	CON %01111111        	' 750ms,   0.0625°C 



Data @0,20,215,76,69,135,37,36,87,4,5,255


PortA=%00000100
TrisA=%00111000
PortB=%11111111
TrisB=%00000000

ASM
INT_LIST macro ; IntSource, Label, Type, ResetFlag?
    INT_Handler TMR1_INT, _DISP, PBP, yes
  endm
  INT_CREATE ; Creates the interrupt processor
ENDASM

@ INT_ENABLE TMR1_INT ; enable Timer 1 interrupts
T1CON = $1 

' Init Sensor 1
 OWOUT DQ, 1, [$CC, $4E, 0, 0, DS18B20_12bit]
 OWOut DQ, 1, [$CC, $48]                   ' Start temperature conversion
 OWOut DQ, 1, [$CC, $B8] 
 OWOut DQ, 1, [$CC, $BE] 
 Pause 50
 OWIn DQ, 2, [temperature.byte0, temperature.byte1]

Main:
' Start temp.conv.Sensor1
 OWOut DQ, 1, [$CC, $44] 
 OWOut DQ, 1, [$CC, $BE]
 OWIn DQ, 2, [temperature.byte0, temperature.byte1]  

If Temperature.15 then       
  Temperature= ~Temperature +1
  Sign  = 1
Endif
 
Dummy = 625 * Temperature
TempC = DIV32 10 
TempC = (Temperature & $7FF) >> 4
Float = ((Temperature.Lowbyte & $0F ) * 25 )>>2
Temperature = TempC*100 + Float

If Sign=1 then
  V= 10000 - Temperature            
else
  V= 10000 + Temperature
EndIf

If V >= 10000 then                  
  Temperature=V-10000
  sign = " "                   
else                                   
  Temperature=10000-V                 
  sign = "-"
EndIf

Temperature=Temperature/10

Gosub Selectie

Goto Main

'======================================================================================
Selectie :

If sign = "-" then
PortB = %11101111					
else 
PortB = %11111111					
endif

IF Temperature DIG 2 = 0 THEN
digit = " "
    else
digit = Temperature dig 2
ENDIF
    read digit, DIGIT_2

digit = Temperature dig 1
    read digit, DIGIT_1
    
digit = Temperature dig 0
    read digit, DIGIT_0
Return    
'====================================================================================== 
Disp:
  T1CON.0 = 0                ; stop timer
  TMR1H = %11111100
  TMR1L = %00011111
  T1CON.0 = 1                ; restart timer

Common_1 = 1 : PAUSE 1 : Common_1 = 0	
      
PortB = DIGIT_2
Common_2 = 1 : PAUSE 1 : Common_2 = 0

PortB = DIGIT_1
Common_3 = 1 : DP = 0 : PAUSE 1 : Common_3 = 0 : DP = 1

PortB = DIGIT_0
Common_4 = 1 : PAUSE 1 : Common_4 = 0

@ INT_RETURN

...but I have some errors :

ERROR Line 95: Syntax error. (ReEnterPBP.bas)
ERROR Line 128: Redefiniton of LABEL Vars_Saved. (ReEnterPBP.bas)
ERROR Line 128: Syntax error. (ReEnterPBP.bas)
Advices ?! Thanks !

[Darrel Taylor]

DT_INTS only works with the MPASM assembler.
Your device statement indicates you are trying to use the old PM assembler.

But I can say that 1-Wire and ASM Interrupts don't get along very well.
1-Wire has very strict timing requirements. And ASM Interrupts have a tendancy to disturb that timing.

1-Wire commands take enough time that if you stop the interrupts to do a software OWOUT/IN ... it will cause blinking.

The only way I can see to scan LED's at a constant rate, and do 1-Wire I/O at the same time ... is to do the 1-Wire communications by Interrupts too.
Sorry, don't have sample code.