Help with variable types
Lawrence Shafer
Posts: 12
I am building a temperature controller for a greenhouse stove so I don't have time to properly search this out for myself, so I ask your help. Why cannot I use "addr = SDEC temp"? how would I go about doing this? everything else works as advertised, but this one last thing... here is the whole code, very messy and big, but so be it for this time. Thank you in advance. ~Lawrence
' =========================================================================
'
' File....... LCD_AppMod_Demo.BS2
' Purpose.... Demonstrates the LCD Terminal AppMod
' Author..... Parallax, Inc. (Copyright 2003-04, All Rights Reserved)
' E-mail..... support@parallax.com
' Started....
' Updated.... 13 JAN 2004
'
' {$STAMP BS2}
' {$PBASIC 2.5}
'
' =========================================================================
' -----[noparse][[/noparse] Program Description ]---------------------------------------------
'
' This program demonstrates the use of the Parallax LCD Terminal AppMod
' with any BS2-series microcontroller. This program uses conditional
' compilation techniques which make it completely BS2-agnostic. Custom
' character generation and animation is demonstrated.
' -----[noparse][[/noparse] I/O Definitions ]-------------------------------------------------
E PIN 1 ' LCD Enable (1 = enabled)
RW PIN 2 ' Read/Write\
RS PIN 3 ' Reg Select (1 = char)
LcdDirs VAR DIRB ' dirs for I/O redirection
LcdBusOut VAR OUTB
LcdBusIn VAR INB
' -----[noparse][[/noparse] Constants ]-------------------------------------------------------
#DEFINE _LcdReady = ($STAMP = BS2P) OR ($STAMP = BS2PE)
LcdCls CON $01 ' clear the LCD
LcdHome CON $02 ' move cursor home
LcdCrsrL CON $10 ' move cursor left
LcdCrsrR CON $14 ' move cursor right
LcdDispL CON $18 ' shift chars left
LcdDispR CON $1C ' shift chars right
LcdDDRam CON $80 ' Display Data RAM control
LcdCGRam CON $40 ' Character Generator RAM
LcdLine1 CON $80 ' DDRAM address of line 1
LcdLine2 CON $C0 ' DDRAM address of line 2
LcdScrollTm CON 150 ' LCD scroll timing (ms)
' -----[noparse][[/noparse] Variables ]-------------------------------------------------------
addr VAR Word ' address pointer
crsrPos VAR Byte ' cursor position
char VAR Byte ' character sent to LCD
idx VAR Byte ' loop counter
scan VAR Byte ' loop counter
buttons VAR Nib
btnA VAR buttons.BIT0 ' left-most button
btnB VAR buttons.BIT1
btnC VAR buttons.BIT2
btnD VAR buttons.BIT3 ' right-most
btnDemo VAR Byte ' loop counter
set VAR Word ' set temp
Msg4t VAR Word
onOff VAR Byte
servoPos VAR Word
sign2 VAR servoPos.BIT15
' ===================== Define Pins and Variables for DS1620================
DQ CON 15 ' Pin 2 <=> DQ.
CLK CON 14 ' Pin 1 => CLK.
RST CON 13 ' Pin 0 => RST (high = active).
DSdata VAR Word ' Word variable to hold 9-bit data.
DSdataC VAR Word ' Word variable to hold 9-bit data.
DSdataF VAR Word ' Word variable to hold 9-bit data.
Sign VAR DSdata.BIT8 ' Sign bit of raw temperature data.
T_sign VAR Bit ' Saved sign bit for converted temperature.
' ===================== Define DS1620 Constants ===================
' >>> Constants for configuring the DS1620
Rconfig CON $AC ' Protocol for 'Read Configuration.'
Wconfig CON $0C ' Protocol for 'Write Configuration.'
CPU CON %10 ' Config bit: serial thermometer mode.
NoCPU CON %00 ' Config bit: standalone thermostat mode.
OneShot CON %01 ' Config bit: one conversion per start request.
Cont CON %00 ' Config bit: continuous conversions after start.
' >>> Constants for serial thermometer applications.
StartC CON $EE ' Protocol for 'Start Conversion.'
StopC CON $22 ' Protocol for 'Stop Conversion.'
Rtemp CON $AA ' Protocol for 'Read Temperature.'
' >>> Constants for programming thermostat functions.
RhiT CON $A1 ' Protocol for 'Read High-Temperature Setting.'
WhiT CON $01 ' Protocol for 'Write High-Temperature Setting.'
RloT CON $A2 ' Protocol for 'Read Low-Temperature Setting.'
WloT CON $02 ' Protocol for 'Write Low-Temperature Setting.'
' -----[noparse][[/noparse] EEPROM Data ]-----------------------------------------------------
CC0 DATA $0E, $1F, $1C, $18, $1C, $1F, $0E, $00 ' char 0
CC1 DATA $0E, $1F, $1F, $18, $1F, $1F, $0E, $00 ' char 1
CC2 DATA $0E, $1F, $1F, $1F, $1F, $1F, $0E, $00 ' char 2
Smiley DATA $0E, $0A, $0E, $00, $00, $00, $00, $00 ' smiley
Deg DATA $0E, $0A, $0E, $00, $00, $00, $00, $00 ' degree sign
Msg1 DATA "Starting"
Msg20 DATA "Heat Off"
Msg21 DATA "Heat On"
Msg3 DATA " Set At "
Msg4 DATA 3, "F "
' -----[noparse][[/noparse] Initialization ]--------------------------------------------------
Initialize:
NAP 5 ' let LCD self-initialize
DIRL = %11111110 ' setup pins for LCD
LCD_Init:
#IF _LcdReady #THEN
LCDCMD E, %00110000 : PAUSE 5 ' 8-bit mode
LCDCMD E, %00110000 : PAUSE 0
LCDCMD E, %00110000 : PAUSE 0
LCDCMD E, %00100000 : PAUSE 0 ' 4-bit mode
LCDCMD E, %00101000 : PAUSE 0 ' 2-line mode
LCDCMD E, %00001100 : PAUSE 0 ' no crsr, no blink
LCDCMD E, %00000110 ' inc crsr, no disp shift
#ELSE
LcdBusOut = %0011 ' 8-bit mode
PULSOUT E, 3 : PAUSE 5
PULSOUT E, 3 : PAUSE 0
PULSOUT E, 3 : PAUSE 0
LcdBusOut = %0010 ' 4-bit mode
PULSOUT E, 3
char = %00101000 ' 2-line mode
GOSUB LCD_Command
char = %00001100 ' on, no crsr, no blink
GOSUB LCD_Command
char = %00000110 ' inc crsr, no disp shift
GOSUB LCD_Command
#ENDIF
Download_Chars: ' download custom chars
char = LcdCGRam ' point to CG RAM
GOSUB LCD_Command ' prepare to write CG data
FOR idx = CC0 TO (Smiley + 7) ' build 4 custom chars
READ idx, char ' get byte from EEPROM
GOSUB LCD_Write_Char ' put into LCD CG RAM
NEXT
' -----[noparse][[/noparse] Program Code ]----------------------------------------------------
Main:
set = 74 ' default temp
char = LcdCls ' clear the LCD
GOSUB LCD_Command
PAUSE 500
Write_Splash:
addr = Msg1 ' point to message
GOSUB LCD_Put_String ' write it
PAUSE 1000
Initialize_DS1620:
LOW RST ' Deactivate '1620 for now.
HIGH CLK ' Put clock in starting state.
PAUSE 100 ' Let things settle down a moment.
HIGH RST ' Activate the '1620 and set it for continuous..
SHIFTOUT DQ,CLK,LSBFIRST,[noparse][[/noparse]Wconfig,CPU+Cont] ' ..temp conversions.
LOW RST ' Done--deactivate.
PAUSE 50 ' Wait for the EEPROM to self-program.
HIGH RST ' Now activate it again and send the..
SHIFTOUT DQ,CLK,LSBFIRST,[noparse][[/noparse]StartC] ' Send start-conversion protocol.
LOW RST ' Done--deactivate.
Show_Buttons:
char = LcdCls ' clear the LCD
GOSUB LCD_Command
PAUSE 100
'addr = Msg4 ' write "Buttons:"
'GOSUB LCD_Put_String
MainLoop:
DO ' Main Loop
FOR btnDemo = 1 TO 100 STEP 2 ' read temp once
IF btnDemo = 1 THEN
GOSUB Get_Temp
char = LcdLine1 + 2
GOSUB LCD_Command
addr = DSdataF ' write temp in F
GOSUB LCD_Put_String
ENDIF
GOSUB servo
char = LcdLine2 + 0 ' show on 2nd line
GOSUB LCD_Command
IF btnDemo = 1 THEN
addr = SDEC set
GOSUB LCD_Put_String
ELSEIF btnDemo = 61 THEN
IF set < DSdataF THEN
addr = Msg20
ELSE
addr = Msg21
ENDIF
ELSEIF btnDemo = 81 THEN
addr = Msg3
ENDIF
GOSUB LCD_Put_String
'GOSUB LCD_Write_Char
GOSUB LCD_Get_Buttons ' read/debounce buttons
IF buttons.LOWBIT(3) THEN GOTO MainLoop ' exit loop and refresh if btn pressed
NEXT
LOOP
GOTO Main ' run demo again
END
' -----[noparse][[/noparse] Subroutines ]-----------------------------------------------------
' Writes stored (in DATA statement) zero-terminated string to LCD
' -- position LCD cursor
' -- point to 0-terminated string (first location in 'addr')
servo:
'DEBUG SDEC set, CR
servoPos = 1000 - (set * 100) + (DSdataF * 100)
IF sign2 = 1 THEN servoPos = 0
servoPos = servoPos MIN 500 MAX 2800
FOR idx = 1 TO 12
PULSOUT 8, servoPos
PAUSE 10
NEXT
RETURN
Get_Temp:
HIGH RST ' Activate the '1620.
SHIFTOUT DQ,CLK,LSBFIRST,[noparse][[/noparse]Rtemp] ' Request to read temperature.
SHIFTIN DQ,CLK,LSBPRE,[noparse][[/noparse]DSdata\9] ' Get the temperature reading.
LOW RST
T_sign = Sign ' Save the sign bit of the reading.
DSdata = DSdata/2 ' Scale reading to whole degrees C.
IF T_sign = 0 THEN no_neg1
DSdata = DSdata | $FF00 ' Extend sign bits for negative temps.
no_neg1:
'DEBUG SDEC DSdata," degrees C",CR ' Show signed temperature in C.
DSdataC = DSdata
DSdata = (DSdata */ $01CC) ' Multiply by 1.8.
IF T_sign = 0 THEN no_neg2 ' If negative, extend sign bits.
DSdata = DSdata | $FF00
no_neg2:
DSdata = DSdata + 32 ' Complete the conversion.
'DEBUG SDEC DSdata," degrees F",CR ' Show signed temperature in F.
DSdataF = DSdata - 5
RETURN
LCD_Put_String:
DO
READ addr, char
IF (char = 0) THEN EXIT
GOSUB LCD_Write_Char
addr = addr + 1
LOOP
RETURN
' Send command to LCD
' -- put command byte in 'char'
LCD_Command: ' write command to LCD
#IF _LcdReady #THEN
LCDCMD E, char
RETURN
#ELSE
LOW RS
GOTO LCD_Write_Char
#ENDIF
' Write character to current cursor position
' -- but byte to write in 'char'
LCD_Write_Char: ' write character to LCD
#IF _LcdReady #THEN
LCDOUT E, 0, [noparse][[/noparse]char]
#ELSE
LcdBusOut = char.HIGHNIB ' output high nibble
PULSOUT E, 3 ' strobe the Enable line
LcdBusOut = char.LOWNIB ' output low nibble
PULSOUT E, 3
HIGH RS ' return to character mode
#ENDIF
RETURN
' Reads byte from LCD
' -- put byte address in 'addr'
' -- returns byte read in 'char'
LCD_Read_Char: ' read character from LCD
#IF _LcdReady #THEN
LCDIN E, addr, [noparse][[/noparse]char]
#ELSE
char = addr ' move cursor
GOSUB LCD_Command
HIGH RS ' data command
HIGH RW ' read
LcdDirs = %0000 ' make LCD bus inputs
HIGH E
char.HIGHNIB = LcdBusIn ' get high nibble
LOW E
HIGH E
char.LOWNIB = LcdBusIn ' get low nibble
LOW E
LcdDirs = %1111 ' return data lines to outputs
LOW RW
#ENDIF
RETURN
' Read and debounce the LCD AppMod buttons
LCD_Get_Buttons:
LcdDirs = %0000 ' make LCD bus inputs
buttons = %1111 ' assume all pressed
FOR scan = 1 TO 10
buttons = buttons & LcdBusIn ' make sure button held
PAUSE 10 ' debounce 10 x 5 ms
NEXT
LcdDirs = %1111 ' return bus to outputs
IF buttons.LOWBIT(0) THEN
set = set - 1
GOTO MainLoop
ELSEIF buttons.LOWBIT(1) THEN
set = set + 1
GOTO MainLoop
ENDIF
RETURN
Comments
It's not hard to write a simple output conversion routine. The biggest problem is where to put the result (as a string). With
the limited variable storage in the Stamps (26 bytes of variable space), it's much better to do conversions one character at
a time and send it to the specific device rather than store it. The LCDOUT statement, for example, allows the SDEC formatter.
if value < 0 then value = -value char = "-" gosub sendToLCD endif leading = 0 for i = 4 to 0 if ((value dig i) > 0) or (leading <> 0) or (i = 0) char = (value dig i) + "0" gosub sendToLCD leading = 1 endif next iThis routine outputs a sign if the value is negative, suppresses leading zeros, and outputs at least one digit.
The routine sendToLCD sends the character in char to the LCD.
Like the DEC operator, it suppresses leading zeros, so it comes out as two characters "72" instead of "00072".
DSdata might possibly go negative. Maybe not in your application. But I think there is a bug lurking in your get_Temp routine for the DS1620. The */ operator does not work correctly on negatives.
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Tracy Allen
www.emesystems.com