A more program space efficient way of doing ta whole heap of IFs????

[Darrel Taylor]

OK, so let's go with Steve's idea and put it in EEPROM.

88 words.

supply_in  VAR BYTE
max_duty   VAR BYTE
ItemNo     VAR BYTE
Temp       VAR BYTE
'
supply_Max  DATA 252,250,248,245,240,237,234,231,229,226,223,220,218,215,212,210,207,204,201,199,196,193,187,0
Set_duty    DATA 154,155,156,157,159,160,161,163,165,167,169,172,175,179,181,182,184,188,191,195,214,238,251,255
'
FOR ItemNo = 0 TO (Set_duty - supply_Max)
    READ (supply_max + ItemNo), Temp
    IF supply_in > Temp THEN
        READ  (Set_duty + ItemNo), Temp
        max_duty = Temp
        EXIT
    ENDIF
NEXT ItemNo

I haven't tested it, but it looks right.
Check my work.

[HankMcSpank]

Wow....what can I say Darrel....you lost me after the elseif post, but I'm gonna read it again & again until it sinks in!

(also thank you steve ....all great stuff)

Edit: Even just rolling with the ELSEIF melarkey ...my program now compiles at 1643 words ...it was maxing out before (greater than 2048 words), so even if I never get to understand the EEPROM method (& the initial indications aren't favourable, lol!) then nevertheless you've saved the day!

[Demon]

PICs have 2 areas of memory: codespace, for your program, and eeprom, you use DATA to store data and READ to get at it (you can also WRITE to it during program execution).

Eeprom is a simple way to store tables and then use For loops to scan through them later. Three common uses; character definitions for LCDs, conversion tables and saving PIN numbers.

I think Melanie has a thread somewhere on how to use some of that eeprom area for codespace.

[HankMcSpank]

PICs have 2 areas of memory: codespace, for your program, and eeprom, you use DATA to store data and READ to get at it.

Eeprom is a simple way to store tables and then use For loops to scan through them later. Two common uses; character definitions for LCDs and conversion tables.

I think Melanie has a thread somewhere on how to use some of that eeprom area for codespace.

Thanks Robert (a cool name ;-) )...while I'm fairly clued up on how to get the PIC to work now (as well as being reasonably savvy on the electronics /interfacing aspect), the darned pesky coding world is still totally flat in my eyes!! (this is frustrating as I have a head brimmed with ideas...but no quick way to get them out of my fingertips & into a PIC)

I'll have to take a night out to get the hang of using EEPROM so I'll have a search for any related threads outlining how to get started with them.

[mister_e]

OK, so let's go with Steve's idea and put it in EEPROM.

88 words.

supply_in  VAR BYTE
max_duty   VAR BYTE
ItemNo     VAR BYTE
Temp       VAR BYTE
'
supply_Max  DATA 252,250,248,245,240,237,234,231,229,226,223,220,218,215,212,210,207,204,201,199,196,193,187,0
Set_duty    DATA 154,155,156,157,159,160,161,163,165,167,169,172,175,179,181,182,184,188,191,195,214,238,251,255
'
FOR ItemNo = 0 TO (Set_duty - supply_Max)
    READ (supply_max + ItemNo), Temp
    IF supply_in > Temp THEN
        READ  (Set_duty + ItemNo), Temp
        max_duty = Temp
        EXIT
    ENDIF
NEXT ItemNo

I haven't tested it, but it looks right.
Check my work.

Option 2:
Could also shave it a lil more, but use a single and larger Lookup...

DATA @188, ....all duty result from 188........256 bytes available btw
.
.
.
.
if supply_in< 188   then 
    max_duty = 255
    else
         READ Supply_in, Max_duty
    endif

couldn't be more simple I guess

I know you love challenge Darrel :P

[HankMcSpank]

OK, so let's go with Steve's idea and put it in EEPROM.

88 words.

supply_in  VAR BYTE
max_duty   VAR BYTE
ItemNo     VAR BYTE
Temp       VAR BYTE
'
supply_Max  DATA 252,250,248,245,240,237,234,231,229,226,223,220,218,215,212,210,207,204,201,199,196,193,187,0
Set_duty    DATA 154,155,156,157,159,160,161,163,165,167,169,172,175,179,181,182,184,188,191,195,214,238,251,255
'
FOR ItemNo = 0 TO (Set_duty - supply_Max)
    READ (supply_max + ItemNo), Temp
    IF supply_in > Temp THEN
        READ  (Set_duty + ItemNo), Temp
        max_duty = Temp
        EXIT
    ENDIF
NEXT ItemNo

I haven't tested it, but it looks right.
Check my work.

I originally shyed away from using suggestion, on account the initial idea provided rescued me back sufficient space, but alas, things have just got too tight, so I've just tried this latter suggestion...it worked first time & has rescued me back a good bit of space (room to breathe again!)

I'll admit I don't totally understand what's going one (other than we're storing stuff in EEPROM, then cleverly marrying it up), I'll addess my inner "huh?" demons & work this out soon, but for now I'm just chuffed the enigma works...as a bonus it's far easier for me to mate the values (the formatting on here clouds it, but it's as clear as day in reality)

Many thanks.