Any idea's on porting this to PBP?

[Ryan7777]

I copied this from scott edwards, all the code is his, i just modified it a little to try it out with PBP, all i get is a blank LCD. my version gets rid of the nibble variable, which is where i think it might go wrong, if someone could get this to work it would benifit everyone im sure. im using a 4X20 LCD, i've used a different aproach to large letters that worked fine but ate up most of my 16F648A's resorces (for a compass heading display).

ALL PROPS TO SCOTT EDWARDS AND SEETRON!!!


CMCON = 7 ' Turn off un-needed PIC hardware
VRCON = 0 ' '' ''
CCP1CON = 0 ' '' ''
INTCON = %00000000 ' '' ''

I con $FE ' Instruction prefix.
ClrLCD con 1 ' Clear-LCD instruction.

cgRAM con $40 ' Address 0 of CG RAM.
EEptr var word ' Pointer into EEPROM.
pat var EEptr ' Alias for EEptr.
dispVal var word ' Value to be displayed as big digits.
temp var byte ' Temporary byte variable.
decade var word
nbl var byte ' Index into number-pattern tables. changed.was a NIBBLE
digit var byte ' Current digit to display
line var byte ' LCD line

' ====This section may be omitted with newer (post July 96)
' ====4x20 Serial LCD modules. Cut from here...============== >>>

bitPat0 DATA 0,0,0,1,3,7,15,31 ' Left-right up-ramp shap
bitPat1 DATA 0,0,0,16,24,28,30,31 ' Right-left " "
bitPat2 DATA 31,15,7,3,1,0,0,0 ' Left-right down ramp.
bitPat3 DATA 31,30,28,24,16,0,0,0 ' Right-left " "
bitPat4 DATA 0,0,0,0,31,31,31,31 ' Lower block.
bitPat5 DATA 31,31,31,31,0,0,0,0 ' Upper block.
bitPat6 DATA 31,31,31,31,31,31,31,31 ' Full block.
bitPat7 DATA 0,0,0,0,0,0,0,0 ' Full blank

' <<<...to here. ===============================================

low 0 ' Make the serial output low
pause 1000 ' Let the LCD wake up.

' ====This section may be omitted with newer (post July 96)
' ====4x20 Serial LCD modules. Cut from here...============= >>>

LCDOUT I,cgRAM ' Enter CG RAM.
for EEptr = 0 to 63 ' Write the bit patterns
Read EEptr,temp ' to the LCD.
LCDout temp
next

' <<<...to here. ===============================================
LCDOUT I,ClrLCD ' Clear the LCD.
pause 1

' ================================================== ======================
' Demo Loop: Show dispVal in Big Numerals, Increment, Loop
' ================================================== ======================

again:
gosub bigLCD
dispVal = dispVal + 1
pause 500
goto again:

' ================================================== ======================
' Subroutine Displaying Large Numbers
' ================================================== ======================

bigLCD:
for line = 0 to 3
decade = 1000
lookup line,[$80,$C0,$94,$D4],temp
LCDOUT I,temp
for digit = 3 to 0
nbl = dispVal dig digit
gosub getPattern:
if dispVal = 0 and digit = 0 then skip0:
if dispVal < decade then blankIt:
skip0:
LCDOUT pat.bIT15,pat.bit14,pat.bit13,pat.bit12,pat.bit11, pat.bit10,pat.bit9,pat.bit8,pat.bit7,pat.bit6,pat. bit5,pat.bit4,pat.bit3,pat.bit2,pat.bit1,pat.bit0 ' was NIBS!
goto cont:
blankIt:
LCDOUT " "
cont:
if digit = 0 then skip1:
LCDOUT 32
skip1:
decade = decade/10
next
next
return

' ================================================== ======================
' Subroutines Defining Big-Character Patterns
' ================================================== ======================
getPattern:
branch line,[first,second,third,fourth]
' 0 1 2 3 4 5 6 7 8 9
' --- --- --- --- --- --- --- --- --- ---
first:
lookup nbl,[$0551,$7067,$0551,$0551,$6776,$6555,$0557,$2556,$0 551,$0551],pat
return
second:
lookup nbl,[$6776,$7767,$7743,$7743,$6776,$2441,$6041,$7703,$2 443,$6776],pat
return
third:
lookup nbl,[$6776,$7767,$0577,$7751,$2556,$7776,$6776,$7767,$0 551,$2536],pat
return
fourth:
lookup nbl,[$2443,$7464,$6444,$2443,$7776,$2443,$2443,$7767,$2 443,$7443],pat
return

[ErnieM]

I don't see any "DEFINE LCD" entries to tell PBP where you wired the LCD. Unless you wire to the default lines you'll get a blank just that: a blank display.

Check pg 95 of the manual under LCDOUT.

[Ryan7777]

It is wired default........... and it works fine with simple LCDOUT "hello"
or the following (NNW) in large 4 line tall font.. just need help getting my first question answered, how to port the code, that was written for BS2 to PBP?
i couldnt use nibble (WHY IS THERE NO NIBBLE IN PBP?), forcing me to break
pat into 16 bits rather than 4 nibbles (pat.nib3,pat.nib2,pat.nib1,pat.nib0)

THIS WORKS FINE, LCD IS WIRED IN DEFAULT.
sub1:
LCDOUT CMD, LcdCls ' Clear the LCD
PAUSE 1

LCDOUT CMD, LcdLine1 + 3, 6,1,7,6,7,6,1,7,6,7,6,7,7,6
LCDOUT CMD, LcdLine2 + 3, 6,2,1,6,7,6,2,1,6,7,6,7,7,6
LCDOUT CMD, LcdLine3 + 3, 6,7,2,6,7,6,7,2,6,7,6,0,1,6
LCDOUT CMD, LcdLine4 + 3, 6,7,7,6,7,6,7,7,6,7,6,3,2,6

RETURN

[mister_e]

If i understand your 'nibble' stuff...


WordA Var Word
Nibble1 Var Byte
Nibble2 Var Byte
Nibble3 Var Byte
Nibble4 Var Byte

WordA=$1234
Nibble1=WordA.Highbyte>>4
Nibble2=WordA.Highbyte&$0F
Nibble3=WordA.LowByte>>4
Nibble4=WordA.Lowbyte&$0F

[Ryan7777]

Sorry i didnt explain that the code was originally written for a basic stamp,
hence the nibble sized variable in question. the code is for displaying large charaters on a 4x20 serial LCD or serial backpack equiped LCD. the code writes custom characters to the LCD, then arranges them to make the large 4 line tall numbers (0-9). all this was spit out serially to the LCD. I changed all the serouts in the origonal code to LCDOUT in proper PBP form, but since PBP doesnt have a nibble sized variable, only bytes and words, the WORD sized variable "pat" can't be broken into 4 NIB's (i.e pat.NIB0) like it will let you in pBasic. it can only do two bytes or 16 bits.. i think that is the reason my version of the code (from my first post) isnt working. all i get is a blank LCD.. it would be nice to use this code to display large numbers because it only takes up about 600 WORDs, i've done a version that displays the 16 compass points (NNW) in large text using the first part of this code to write the custom bit patterns to my LCD's CGRAM, but it takes up 3397 WORDs using BRANCH to a subroutine for each compass point which is spelled out in my second reply, anyway, the original code is at:

http://www.seetron.com/pdf/lcd_an1.pdf

and as you can see it is written for pBASIC and meant for serial LCD's, i want to convert it to PBP for a parallel LCD..

[Darrel Taylor]

Hey Ryan,

mister_e's concept is correct, you just need to put it into the LCDOUT statement.

LCDOUT Nibble1, Nibble2, Nibble3, Nibble4

or you can just put it all in there in one shot...

LCDOUT pat.Highbyte>>4, pat.Highbyte&$0F, pat.LowByte>>4, pat.Lowbyte&$0F
<br>

[Ryan7777]

Still just a blank LCD, I expected to get at least some garbage on the display. anyone got any other idea's what might be wrong? I added:
LCDOUT "TEST"
PAUSE 1000
LCDOUT $FE, 1

to the code just before the demo loop part and it display's correctly and then clear screens, so i guess its not totally blank, but it doesn't do much else.
I also tried hooking the LCD to my BS2p and ran my modified version of the code using LCD out in proper pBasic format and it sorta worked but only displayed the bottom 1/4 of the numbers all shifted up to the top line. like what should be displaying on the 4th line of the LCD was showing on the top line and all the rest was off screen.

[mister_e]

There's few missing details here
OSC type & speed (4,8,16,20.... or internal)
LCD DEFINEs
Config Fuses
Schematic

Did you added ?
DEFINE LCD_LINES 4

You can also use LCDOUT $fe,1,"Hello"

Some LCD may need some COMMANDUS and DATAUS fine tuning too.

[Darrel Taylor]

Here is a complete modification of Scott Edwards Program for big nums.

Changes are marked in red, and have been tested.
;Initialize your hardware first

'BIGNUMS.BS2 (Display four 1" digits on 4x20 display)
' Connect the serial input of a Backpack-equipped 4x20 display to
' BS2 pin P0 and run this program. The program will define a set
' of symbols that allow it to display 4-line-tall numerals on the
' LCD. To incorporate this capability into your own programs, just
' substitute your code for the demo loop. When you want to display
' a value (0-9999) in big numerals, write it to dispVal, then
' gosub bigLCD.
I con 254 ' Instruction prefix.
ClrLCD con 1 ' Clear-LCD instruction.
N96N con $4054 ' 9600 baud, inverted, no parity.
cgRAM con 64 ' Address 0 of CG RAM.
EEptr var word ' Pointer into EEPROM.
pat var EEptr ' Alias for EEptr.
dispVal var word ' Value to be displayed as big digits.
temp var byte ' Temporary byte variable.
decade var word
nbl var byte ' Index into number-pattern tables.
digit var byte ' Current digit to display
line var byte ' LCD line

LCDOUT I,ClrLCD
PAUSE 500

' ====This section may be omitted with newer (post July 96)
' ====4x20 Serial LCD modules. Cut from here...============== >>>
bitPat0 DATA 0,0,0,1,3,7,15,31 ' Left-right up-ramp shape.
bitPat1 DATA 0,0,0,16,24,28,30,31 ' Right-left " "
bitPat2 DATA 31,15,7,3,1,0,0,0 ' Left-right down ramp.
bitPat3 DATA 31,30,28,24,16,0,0,0 ' Right-left " "
bitPat4 DATA 0,0,0,0,31,31,31,31 ' Lower block.
bitPat5 DATA 31,31,31,31,0,0,0,0 ' Upper block.
bitPat6 DATA 31,31,31,31,31,31,31,31 ' Full block.
bitPat7 DATA 0,0,0,0,0,0,0,0 ' Full blank
' <<<...to here. ===============================================
;low 0 ' Make the serial output low
;pause 1000 ' Let the LCD wake up.
' ====This section may be omitted with newer (post July 96)
' ====4x20 Serial LCD modules. Cut from here...============= >>>
;serout 0,N96N,[I,cgRAM] ' Enter CG RAM.
LCDOUT I,cgRAM

for EEptr = 0 to 63 ' Write the bit patterns
Read EEptr,temp ' to the LCD.
; serout 0,N96N,[temp]
lcdout temp
next
' <<<...to here. ===============================================
;serout 0,N96N,[I,ClrLCD] ' Clear the LCD.
LCDOUT I, ClrLCD
pause 1
' ================================================== ======================
' Demo Loop: Show dispVal in Big Numerals, Increment, Loop
' ================================================== ======================
again:
gosub bigLCD
dispVal = dispVal + 1
pause 500
goto again
' ================================================== ======================
' Subroutine Displaying Large Numbers
' ================================================== ======================
bigLCD:
for line = 0 to 3
decade = 1000
lookup line,[128,192,148,212],temp

; serout 0,N96N,[I,temp]
LCDOUT I, temp
for digit = 3 to 0 step -1
nbl = dispVal dig digit
gosub getPattern
if dispVal = 0 and digit = 0 then skip0
if dispVal < decade then blankIt
skip0:
; serout 0,N96N,[pat.nib3,pat.nib2,pat.nib1,pat.nib0]
LCDOUT pat.Highbyte>>4, pat.Highbyte&$0F, pat.LowByte>>4, pat.Lowbyte&$0F

goto cont
blankIt:
; serout 0,N96N,[" "]
lcdout " "
cont:
if digit = 0 then skip1
; serout 0,N96N,[32]
LCDOUT 32
skip1:
decade = decade/10
next
next
return
' Subroutines Defining Big-Character Patterns
' ================================================== ======================
getPattern:
branch line,[first,second,third,fourth]
' 0 1 2 3 4 5 6 7 8 9
' --- --- --- --- --- --- --- --- --- ---
first:
lookup2 nbl,[$0551,$7067,$0551,$0551,$6776,$6555,$0557,$2556,$0 551,$0551],pat
return
second:
lookup2 nbl,[$6776,$7767,$7743,$7743,$6776,$2441,$6041,$7703,$2 443,$6776],pat
return
third:
lookup2 nbl,[$6776,$7767,$0577,$7751,$2556,$7776,$6776,$7767,$0 551,$2536],pat
return
fourth:
lookup2 nbl,[$2443,$7464,$6444,$2443,$7776,$2443,$2443,$7767,$2 443,$7443],pat
return

Not too hard eh.

[Ryan7777]

Ok, the step -1 was doing it, i tried LOOKUP2 as a last resort before my last post, but still didnt help. thanks, Darrel! works fine now. i probably would have never got that in a million years. Thanks again!

[Darrel Taylor]

Honestly..., I had to use the MCSP debugger to find the step -1. Saw that the FOR loop was never getting executed. Made it easy.

But a million years, you'd have got it. :)

Glad to help.
<br>

[websmith]

Darrel you are amazing!
I tried this out yesterday and it exactly what I'm looking for ( I am making a fuel consumption / complex odometer for my ancient Land Rover) and as I can't see close up without glasses, but have perfect long distance vision, a normal LCD display on the dashboard is quite useless and I had been considering large 7 seg display, but this is beautiful! Thanks a million.

PS: any tips on saving a counter on power-down? I was going to have the PIC running off big electrolytic for long power down delay, and then have one port sensing the instant loss of the (voltage divided) 12v ignition and then quickly write to EEProm, but would it be clever to use a brown out flag or something like that?

[Darrel Taylor]

Thanks, but the credit goes to Scott Edwards on that one.

If you have a PIC with an LVD (LOW VOLTAGE DETECT) pin. You can use it to generate an interrupt when it detects the loss of power.

Then you can imediately set all pins to input and shut-down any on-chip peripherals to save current.

You should be able to run long enough to save about 8-10 bytes with just 10uf or so..

[Archangel]

Hello Everyone,
This is cool. Anyone got an idea how to force this code to display 4 digits all the time? From 0000 to 9999? Scotts code works well. I tried dispVal = 0000 prior to the LCDOUT I,cgRAM statement and that did alright to start counter at zero and eliminate the initial display of a psudorandom 4 digit number at startup, I am sure it is simple, alas so am I :) .

[Archangel]

Ahhh, I figured out 1 way, Preload with dispVal = 10000. I watched it count up until it overflowed and the zeros remained. Are there better ways ?

[Melanie]

> Anyone got an idea how to force this code to display 4 digits all the time?

LCDOut DEC4 MyVar

[Darrel Taylor]

>> Anyone got an idea how to force this code to display 4 digits all the time?

Just comment out this line ...

; if dispVal < decade then blankIt


Added: Or better yet, make it ...
LeadingZeros VAR BIT

if (LeadingZeros = 0) AND (dispVal < decade) then blankIt


Then if you want leading zero's just set the bit.
<br>

[Archangel]

Thanks Melanie and Darrel,
That's 4 dirrerent ways - Great! It seems there is always more than 1 way.
JS

[isaac]

Hi Guys/Ladies

would this only work with a serial lcd or can the same thing be done for a standard 4x20 Lcd?

Regards
Isaac

[skimask]

would this only work with a serial lcd or can the same thing be done for a standard 4x20 Lcd?

Read Post #9

[isaac]

Oooh Thanks for that
just dont know how i missed that the serial lcd had been commented out and replaced with
Lcdout command

Silly me:)

Isaac