Operating system

David92680

Looking to build a project that uses the basic stamp2 with an operating system to display on an LCD 2x20 display. Will operate menus and options by 3 or 4 button inputs. Looking for some feedback on how I go about building a program to operate like an os on the basic stamp.

allanlane5

It's pretty simple.
The BS2 has 26 bytes of 'RAM' (actually register space). Everything is 'global'.

' {$STAMP BS2}
' {$PBASIC 2.5}
LCD1 DATA "This is the LCD1 screen", 0
LCD2 DATA "This is the LCD2 screen", 0
ButtonHit VAR Byte
MenuState VAR Byte
LCD_Msg·· VAR Word
I·········· ·· VAR Word
SendByte· VAR Byte
MenuState = 0· ' zero is the 'starting' menu.
MAIN:
· GOSUB Read_Buttons· ' Sets ButtonHit to whatever button was hit, or zero if timeout
· GOSUB SendLCD······· ' Sends the LCD message, based on "ButtonHit' and 'MenuState'
· GOTO MAIN

Read_Buttons:
· ' Whatever it takes to read the buttons
· ' and set "ButtonHit"
· RETURN

SendLCD:
· IF MenuState = 0 THEN
··· LCD_Msg· = LCD1
· ENDIF
· GOSUB OutputLCD
· RETURN

OutputLCD:
· I = LCD_Msg
· READ I, SendByte
· DO WHILE SendByte <> 0
··· ' Write SendByte to LCD Port
··· I = I + 1
··· READ I, SendByte
· LOOP
· RETURN
·