LCD Temperature display (#27976 & DS1620)

superpro · 2006-03-16 11:36

I’m looking for a program that will have my LCD (2 row x 16 char non-backlit #27976) display temperature from a DS1620 chip.
·
I also need the circuit design to build it for my HomeWork Board.
·
I’m new and just trying to get started.· Thanks!

RDL2004 · 2006-03-16 15:31

http://www.parallax.com/dl/docs/books/sw/exp/sw28.pdf

I believe the documentation that comes with the LCD explains how to convert the·DEBUG statements to SEROUT to drive the display. If not, it shouldn't be too hard to track down the info.

·- Rick

Chris Savage · 2006-03-16 15:50

The following project is actually a Binary Digital Clock with both a Binary Display (10mm LEDs) and a 7-Segment Digital Display (1" Digits), however it also has a Parallax LCD and displays the Temperature as well as the day and date on the LCD.

http://forums.parallax.com/showthread.php?p=552892

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Chris Savage
Parallax Tech Support
csavage@parallax.com

superpro · 2006-03-17 23:45

Thanks for the help. This site ROCKS!

superpro · 2006-03-19 04:56

I'm not finding the right information to get this working.

I'm willing to pay $$ for this program if anybody can·write it.

Post Edited (superpro) : 3/19/2006 5:15:12 AM GMT

Jon Williams · 2006-03-19 05:22

Download StampWorks 2.0 -- there are LCD experiments and DS1620 experiments; it will be up to you to put the two together, but it shouldn't be too hard.

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Jon Williams
Applications Engineer, Parallax

superpro · 2006-03-19 16:15

Thanks JON!!!!· That gave the solution to my program.

Now I need to display a MAX temp (F) along with the current temp (F) read by the DS1629.

Can someone help me with creating a MAX code that will read on line 2 of the lcd?

superpro · 2006-03-20 19:47

I want to display the current temp on line one, and to display the·maxium temp on line two.

Can someone help me get the correct information to·write this program?

Chris Savage · 2006-03-20 20:13

Post what you have so far and we'll see what we can do with it.· Without knowing how you're handling your data it would be difficult to guide you.

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Chris Savage
Parallax Tech Support
csavage@parallax.com

superpro · 2006-03-21 03:30

' LCD Temperature Display
' Purpose... Temperature

Post Edited (superpro) : 3/23/2006 2:20:22 AM GMT

Chris Savage · 2006-03-21 14:55

Whoops, I probably should've worded it "attach" since pasting it has messed up the formatting.· In any event I wanted you to post it because I thought you were using Jon's code as per above.· But in fact this is code from my Binary/Digital Clock Project.· I already have routines for storing max temperature for this project at home and I will post those later (when I get home).

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Chris Savage
Parallax Tech Support
csavage@parallax.com

superpro · 2006-03-21 17:55

Thanks!

Chris Savage (Parallax) said...
Whoops, I probably should've worded it "attach" since pasting it has messed up the formatting.· In any event I wanted you to post it because I thought you were using Jon's code as per above.· But in fact this is code from my Binary/Digital Clock Project.· I already have routines for storing max temperature for this project at home and I will post those later (when I get home).

superpro · 2006-03-22 03:11

ttt

Chris Savage · 2006-03-22 05:15

ttt???· Anyway, I found my updated code, and the only thing I forgot about was that since I never expect to have negative temperatures it really is designed to store positive values only.· It's only one additional line I added as shown below...

Get_Temp:
  HIGH DS1620                           ' Select DS1620
  SHIFTOUT DataIO, Clock, LSBFIRST,
    [noparse][[/noparse]RdTemp]                            ' Send Read Temp Command
  SHIFTIN DataIO, Clock, LSBPRE,
    [noparse][[/noparse]tempIn\9]                          ' Read Temp Data
  LOW DS1620                            ' Deselect DS1620
  tempIn.BYTE1 = -tempIn.BIT8           ' Extend Sign To 16 Bits
  tempC = tempIn * 5                    ' Convert To C * 5 (Res. 0.5 C)
  tempF = tempC + 2732 * 9 / 50 - 459   ' C * 10 to F (First To K * 10)
  IF tempF > tempMax THEN tempMax = tempF   '<---This line added holds tempMax
  RETURN
 
Show_Temp:
  SEROUT LCD, Baud, [noparse][[/noparse]LcdLine1, "Temp = ", DEC2 tempF, 0, "F ",
    LcdLine2, "Max  = ", DEC2 tempF, 0, "F "]
  RETURN                                ' Display Temp On LCD Display

All you have to do is display it in the routine as shown.· If you need support for negative numbers that's not difficult but since they're not being used in this code I wouldn't worry about it.

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Chris Savage
Parallax Tech Support
csavage@parallax.com

superpro · 2006-03-22 10:43

"ttt"··Is just an acronym·for To The Top.··When a·thread has a new post---it will be To The Top of the Forum.
Thanks for your help in this matter, and for your code in the Binary/Digital Clock Project.

Which Basic Stamp module should I use to make this a stand alone component?

Chris Savage (Parallax) said...
ttt???· Anyway, I found my updated code, and the only thing I forgot about was that since I never expect to have negative temperatures it really is designed to store positive values only.· It's only one additional line I added as shown below..

All you have to do is display it in the routine as shown.· If you need support for negative numbers that's not difficult but since they're not being used in this code I wouldn't worry about it.

Chris Savage · 2006-03-22 15:46

Interesting...All of my new posts appear at the bottom of the current thread.· In any event as far as a BASIC Stamp Module for stand alone operation you could either use a BS2 Module on a Super Carrier Board or you could use the BS2-OEM.· Not really sure of everything connected to this system.

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Chris Savage
Parallax Tech Support
csavage@parallax.com

superpro · 2006-03-23 01:01

Everything is working except the "Max Line" is not holding the Max temp.· The "Max Line" changes (up & down) with the Temp.

I think it needs to write and read the Max temp, right?

Any clues how to fix this?

Post Edited (superpro) : 3/23/2006 1:05:09 AM GMT

Chris Savage · 2006-03-23 01:18

I will have to re-run the code later.· I don't have the circuit setup right now.

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Chris Savage
Parallax Tech Support
csavage@parallax.com

superpro · 2006-03-23 02:18

I have attached my file for you to view/use.

PJAllen · 2006-03-23 02:40

In GetTemp:, change

IF tempF < tempMax THEN tempMax = tempF to

IF tempF·> tempMax THEN tempMax = tempF

Chris Savage · 2006-03-23 05:14

You changed the code...If you back up a few messages you will see that I had the greater than sign there, not the less than sign.·

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Chris Savage
Parallax Tech Support
csavage@parallax.com

superpro · 2006-03-23 10:45

I did that to see if it made any difference to the reading of the Max temp.

If I change it back to" >", or keep it the same, the result will be unchanged.

Thanks.

PJ Allen said...

In GetTemp:, change

IF tempF < tempMax THEN tempMax = tempF to

IF tempF·> tempMax THEN tempMax = tempF

Chris Savage · 2006-03-23 15:18

The code works perfectly...I just tested it.· Your code does not.· The reason is you're not displaying the tempMax in the second line as I am.· You are displaying tempF in both lines, so of course they will follow each other.

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Chris Savage
Parallax Tech Support
csavage@parallax.com

SSteve · 2006-03-23 23:56

I'm a little late to the party, but I just happened to write a program that does what the original poster asked for. The pin connections should be obvious from the constants, but ask if you aren't sure.

I welcome comments on programming style. I'm new to the BASIC Stamp (but not to programming in general).

(I tried to attach the file, but I get a message saying I can't upload files with MIME type www/unknown.)

' {$STAMP BS2}
' {$PBASIC 2.5}

' ------------------------------------------------------------
' I/O Definitions

' LCD connections (block X2 on prof devel board)
E            PIN        1
RW            PIN        2
RS            PIN        3
LcdBus        VAR        OUTB
LcdDir        VAR        DIRL

' Connections to DS1620 (other connections are the same as in StampWorks2.0  book)
DQ            PIN        8
Clock            PIN        9
Reset            PIN        10

' ------------------------------------------------------------
' DS1620 Constants
RdTmp            CON        $AA        ' read temperature
WrHI            CON        $01        ' write TH (high temp)
WrLo            CON        $02        ' write TL (low temp)
RdHi            CON        $A1        ' read TH
RdLo            CON        $A2        ' read TL
RdCntr        CON        $A0        ' read counter
RdSlope        CON        $A9        ' read slope
StartC        CON        $EE        ' start conversion
STOPC            CON        $22        ' stop conversion
WrCfg            CON        $0C        ' write config register
RdCfg            CON        $AC        ' read config register

' ------------------------------------------------------------
' LCD Constants
' LCD Commands - These are sent with RS set to LOW

LcdCls        CON        %00000001    ' Clear the display
LcdHome        CON        %00000010    ' Move cursor home

' Entry Mode commands
LcdIncNoShift    CON        %00000110 ' Inc cursor after writing a
                            ' character, don't shift display
LcdIncAndShift    CON        %00000111 ' Inc cursor after writing a
                            ' character, shift display
LcdDecNoShift    CON        %00000100    ' Dec cursorafter writing a
                            ' character, don't shift display
LcdDecAndShift    CON        %00000101 ' Dec cursor after writing a
                            ' character, shift display
' Display on/off control
' "cursor" sets whether or not cursor is visible
' "blink" sets whether or not the character at the cursor position blinks
LcdDisplayOff        CON        %00001000    ' display off
LcdCrsOffBlnkOff    CON        %00001100    ' display on, cursor off, Blink off
LcdCrsOffBlnkOn        CON        %00001101    ' display on, cursor off, Blink on
LcdCrsOnBlnkOff        CON        %00001110    ' display on, cursor on, Blink off
LcdCrsOnBlnkOn        CON        %00001111    ' display on, cursor on, Blink on

' Cursor/display shift
LcdCrsrL        CON        %00010000        ' Move cursor left
LcdCrsrR        CON        %00010100        ' Move cursor right
LcdDispL        CON        %00011000        ' Shift chars left
LcdDispR        CON        %00011100        ' Shift chars right

' Function Set
Lcd8bit        CON        %0011            ' set to 8-bit mode
Lcd4bit        CON        %0010            ' set to 4-bit mode
' Function Set (these are all for 4-bit mode)
Lcd1Line        CON        %00100000        ' one line of 5x8 chars
Lcd2Line        CON        %00101000        ' two lines of 5x8 chars
Lcd1LineBig    CON        %00100100        ' one line of 5x10 chars

' RAM addresses
LcdGCRam        CON        $40    ' Character Generator RAM
LcdDDRam        CON        $80    ' Display Data RAM control
LcdLine1        CON        $80    ' DDRAM address of line 1
LcdLine2        CON        $C0    ' DDRAM address of line 2

' Special character codes
DegSym        CON        $DF        ' degree symbol


' #DEFINE _LcdReady = ($STAMP >= BS2P)

' ------------------------------------------------------------
' Variables

char            VAR        BYTE        ' Character sent to LCD
idx            VAR        BYTE        ' Loop index

tempIn        VAR        WORD        ' raw temperature
sign            VAR        tempIn.BIT8    ' 1 = negative termperature

tC            VAR        WORD        ' Celcius temp
tF            VAR        WORD        ' Farenheit temp

displayTemp    VAR        WORD        ' The temp to display
displayPos        VAR        BYTE        ' Where to display the temp

LowestTemp        VAR        WORD        ' Lowest recorded temp (in F)
HighestTemp    VAR        WORD        ' Highest recorded temp (in F)

#DEFINE __debugDisplay = 0

' ------------------------------------------------------------
' EEPROM data

MsgF            DATA        ". ", DegSym, "F", 0
MsgC            DATA        ". ", DegSym, "C", 0
MsgHi            DATA        "Hi:   ", 0
MsgLo            DATA        "Lo:   ", 0

' ------------------------------------------------------------
' Initialization

Setup:
#IF (__debugDisplay) #THEN
    DEBUG CLS
#ENDIF

    GOSUB Lcd_2Line_Init

    LowestTemp = 2000
    HighestTemp = 0

    HIGH Reset                                ' alert the DS1620
    SHIFTOUT DQ, Clock, LSBFIRST, [noparse][[/noparse]WrCfg, %10]    ' use with CPU; free-run
    LOW Reset
    PAUSE 10
    HIGH Reset
    SHIFTOUT DQ, Clock, LSBFIRST, [noparse][[/noparse]StartC]        ' start conversions
    LOW Reset

    char = LcdCls                ' clear the LCD
    GOSUB LCD_Cmd
    PAUSE 500

    ' Write the constant part of message
    char = LcdLine1 + 3            ' set address to begin writing
    GOSUB LCD_Cmd
    idx = MsgF                    ' display degrees F message
    GOSUB LCD_Message
    char = LcdLine2 + 3            ' set address to begin writing
    GOSUB LCD_Cmd
    idx = MsgC                    ' display degrees C message
    GOSUB LCD_Message
    char = LcdLine1 + 8            ' display "Hi:   "
    GOSUB LCD_Cmd
    idx = MsgHi
    GOSUB LCD_Message
    idx = MsgF                    ' display degrees F message
    GOSUB LCD_Message
    char = LcdLine2 + 8            ' display "Lo:   "
    GOSUB LCD_Cmd
    idx = MsgLo
    GOSUB LCD_Message
    idx = MsgF                    ' display degrees F message
    GOSUB LCD_Message


' ------------------------------------------------------------
' Program Code

Main:
    DO    
        GOSUB READ_DS1620            ' get the temperature

Display_C:    
#IF __debugDisplay #THEN
    DEBUG (tC.BIT15 * 13 + " "),
        DEC (ABS tF / 10), ".", DEC1 (ABS tF), "° F  ",
        DEC (ABS tC / 10), ".", DEC1 (ABS tC), "° C", CR
#ENDIF
    ' Write degrees Farenheit
    displayPos = LcdLine1
    displayTemp = tF
    GOSUB LCD_Display_Temp

    ' Write degrees Celsius
    displayPos = LcdLine2
    displayTemp = tC
    GOSUB LCD_Display_Temp

    IF (tF > HighestTemp) THEN
        HighestTemp = tF
        displayTemp = tF
        displayPos = LcdLine1 + 11
        GOSUB LCD_Display_Temp
    ENDIF

    IF (tF < LowestTemp) THEN
        LowestTemp = tF
        displayTemp = tF
        displayPos = LcdLine2 + 11
        GOSUB LCD_Display_Temp
    ENDIF

    PAUSE 5000            ' Change this value to change the sample interval
    LOOP

END

' ------------------------------------------------------------
' Subroutines

READ_DS1620:
    HIGH Reset
    SHIFTOUT DQ, Clock, LSBFIRST, [noparse][[/noparse]RdTmp]    ' give command to read temp
    SHIFTIN DQ, Clock, LSBPRE, [noparse][[/noparse]tempIn\9]    ' read the temp
    LOW Reset

    tempIn.BYTE1 = -sign                    ' extend sign bit
    tC = tempIn * 5                        ' convert to tenths
    
    IF (tC.BIT15 = 0) THEN                ' temp c is positive
        tF = tC */ $01CC + 320
    ELSE
        tF = 320 - ((ABS tC) */ $01CC)
    ENDIF
RETURN

' ------------------------------------------------------------
' LCD Subroutines

LCD_4bitInit:
' The program shouldn't call this directly. It is called by "LCD_1Line_Init
' and LCD_2Line_Init
    LCDDir = %11111110
    PAUSE 100
    LcdBus = Lcd8bit            ' 8-bit mode
    PULSOUT E, 3
    PAUSE 5
    PULSOUT E, 3
    PULSOUT E, 3
    LcdBus = Lcd4bit            ' 4-bit mode
    PULSOUT E, 1
RETURN

'** LCD_1Line_Init:
'**     GOSUB LCD_4bitInit
'**     char = Lcd1Line                ' single-line mode
'**     GOSUB LCD_Cmd
'**     char = LcdCrsOffBlnkOff        ' disp on, no crsr or blink
'**     GOSUB LCD_Cmd
'**     char = LCDIncNoShift            ' inc crsr, no disp shift
'**     GOSUB LCD_Cmd
'** RETURN

LCD_2Line_Init:
    GOSUB LCD_4bitInit
    char = Lcd2Line                ' multi-line mode
    GOSUB LCD_Cmd
    char = LcdCrsOffBlnkOff        ' disp on, no crsr or blink
    GOSUB LCD_Cmd
    char = LCDIncNoShift            ' inc crsr, no disp shift
    GOSUB LCD_Cmd
RETURN

LCD_Cmd:
    LOW RS                    ' enter command mode
    ' fall through to LCD_Out
LCD_Out:
    LcdBus = char.HIGHNIB        ' output high nibble
    PULSOUT E, 3                ' strobe the enable line
    LcdBus = char.LOWNIB            ' output low nibble
    PULSOUT E, 3                ' strobe the enable line
    HIGH RS                    ' return to character mode
RETURN    

LCD_Message:                    ' Display the message pointed to by idx
    READ idx, char
    DO WHILE (char <> 0)
        GOSUB LCD_Out            ' write the character
        idx = idx + 1
        READ idx, char
    LOOP
RETURN

LCD_Display_Temp:
    char = displayPos
    GOSUB LCD_Cmd
    char = displayTemp.BIT15 * 13 + " "
    GOSUB LCD_Out
    char = (displayTemp DIG 2) + "0"
    GOSUB LCD_Out
    char = (displayTemp DIG 1) + "0"
    GOSUB LCD_Out
    char = displayPos + 4
    GOSUB LCD_Cmd
    char = (displayTemp DIG 0) + "0"
    GOSUB LCD_Out
RETURN

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OS-X: because making Unix user-friendly was easier than debugging Windows

superpro · 2006-03-24 03:18

Thanks Chris!!! You're right.....again!!! [noparse];)[/noparse]

How can I reset the Max temp by using·pushbutton?

Chris Savage (Parallax) said...
The code works perfectly...I just tested it.· Your code does not.· The reason is you're not displaying the tempMax in the second line as I am.· You are displaying tempF in both lines, so of course they will follow each other.

Chris Savage · 2006-03-24 05:29

In your main loop do something like:

IF IN0 = 1 THEN tempMax = tempF

...assuming you have an active HIGH pushbutton connected to P0.· You get the idea.

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Chris Savage
Parallax Tech Support
csavage@parallax.com

LCD Temperature display (#27976 & DS1620)

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