How to display dot on 7-seg , 4 digit

[paul borgmeier]

I do not need help ... the OP does Anyone is welcome to contribute and chime in.

Maybe I do need help - I need to sharpen/review my PNP circuit abilites a bit and will comment soon.

Others welcome to comment.

EDIT:
based on an offlist conversation with another member

[paul borgmeier]

Sayzer - where did you go ... I thought you were helping me here? .

Chai98a,
As Sayzer was hinting at in his "Large" post, if you are using a "standard" common-sized common anode display, you might want to simplify your circuit and follow something like figure 6 of the below link. Your schematic as draw is not correct and makes little sense (to me).

http://picbasic.com/resources/articles/ledart.htm

Is this an option or are you locked into your hardware as shown in your earlier post?

[sayzer]

We had a long holiday here in Turkey.

Sorry Paul. I was busy with my .... (fill in the blank).


I will post some concept schematics, using PNP, NPN and ULN type of drivers.

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[chai98a]

Now we finish 7 seg display temp form ds1820 about 90%
But we stil have porblem with display fashing and i have try at 20 Mhz cannot resolve it



Code:

Define LOADER_USED 1
DEFINE OSC 4
@ Device pic16F877A, xt_OSC, BOD_OFF, PWRT_ON, WDT_OFF, PROTECT_OFF 'WRT_On

Segments Var PORTC
Digits Var PORTD

i Var Byte
n Var Byte
Value Var Word

' Allocate variables
command var byte ' Storage for command
J var byte ' Storage for loop counter
temp var word ' Storage for temperature
T VAR WORD
DQ var PORTd.4 ' Alias DS1820 data pin
DQ_DIR var TRISd.4 ' Alias DS1820 data direction pin
read_done var byte
Lastdata var word


TRISc = $00 ' Set segment pins to output
TRISd = $f0 ' Set digit pins to output
TrisB = $00
Portb = $00
portd = $ff

DEFINE HSER_RCSTA 90h
DEFINE HSER_TXSTA 24h
DEFINE HSER_SPBRG 12 ' 19200 Bauds ,4 m
'debug ====

' Mainloop to read the temperature and display on LCD


mainloop:
'goto display
'Goto mainloop

Gosub init1820 ' Init the DS1820

command = $cc ' Issue Skip ROM command
Gosub write1820

command = $44 ' Start temperature conversion
Gosub write1820

Pause 2000 ' Wait 2 seconds for conversion to complete

Gosub init1820 ' Do another init

command = $cc ' Issue Skip ROM command
Gosub write1820

command = $be ' Read the temperature
Gosub write1820
Gosub read1820


'Display the decimal temperature
'HSEROUT ["Temp = ",dec (temp>>1),".", dec (temp.0*5)," C",13,10]
'T = ((temp>> 1)*100)+((TEMP.0*5)*10)
'HSEROUT ["Temp = ",dec T ,13,10]
value = ((temp>> 1)*100)+((TEMP.0*5)*10)
GOTO DISPLAY
Goto mainloop ' Do it forever


' Initialize DS1820 and check for presence
init1820:
Low DQ ' Set the data pin low to init
Pauseus 500 ' Wait > 480us
DQ_DIR = 1 ' Release data pin (set to input for high)

Pauseus 100 ' Wait > 60us
If DQ = 1 Then
'Lcdout $fe, 1, "DS1820 not present"
Pause 500
Goto mainloop ' Try again
Endif
Pauseus 400 ' Wait for end of presence pulse
Return


' Write "command" byte to the DS1820
write1820:
For i = 1 to 8 ' 8 bits to a byte
If command.0 = 0 Then
Gosub write0 ' Write a 0 bit
Else
Gosub write1 ' Write a 1 bit
Endif
command = command >> 1 ' Shift to next bit
Next i
Return

' Write a 0 bit to the DS1820
write0:
Low DQ
Pauseus 60 ' Low for > 60us for 0
DQ_DIR = 1 ' Release data pin (set to input for high)
Return

' Write a 1 bit to the DS1820
write1:
Low DQ ' Low for < 15us for 1
@ nop ' Delay 1us at 4MHz
DQ_DIR = 1 ' Release data pin (set to input for high)
Pauseus 60 ' Use up rest of time slot
Return


' Read temperature from the DS1820
read1820:
For i = 1 to 16 ' 16 bits to a word
temp = temp >> 1 ' Shift down bits
Gosub readbit ' Get the bit to the top of temp
Next i
Return

' Read a bit from the DS1820
readbit:
temp.15 = 1 ' Preset read bit to 1
Low DQ ' Start the time slot
@ nop ' Delay 1us at 4MHz
DQ_DIR = 1 ' Release data pin (set to input for high)
If DQ = 0 Then
temp.15 = 0 ' Set bit to 0
Endif
Pauseus 60 ' Wait out rest of time slot
Return
'================== 7 seg ment display ==============================
display:
'value = ((temp>> 1)*100)+((TEMP.0*5)*10)

PORTC = $39
LOW DIGITS.0
PAUSEUS 1500
PORTC = $0

'value = 125
For i = 1 To 4 ' Loop through 4 digits

n = Value Dig i ' Get digit to display

' Gosub display1 ' Display the value
Digits = $ff

Lookup n, [$3F, $06, $5B, $4F, $66, $6D, $7D, $07, $7F, $6F,_
$77, $7C, $39, $5E, $79, $71, $0FF], Segments

If i = 2 then segments = segments + 128 'Digit 2 show dot

Digits = ~Dcd i

NEXT I
goto mainloop
End

[sayzer]

If you have more then 2ms pause in total during the whole process, you will see blinking.

Have your calculator and start adding your pauses.
See what the total is.

Also, remove any repeat routines if any.

I have no time to check your code.

Why don't you use an easier DS1820 code by the way?


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[chai98a]

Hi sayzer thank you we done after try remove 2 ms out.


Buy the way we will post this code in exampls code for share with other peple