LCD and 16F88

[G-R-C]

Hello all
Recently made the to switch from MBasic to PBP.

Here my trouble, my project is using a 16F88 with the 4MHz bootloader.
(So cool you can now use a bootloader with a 16 pin PIC)
Can download/read just fine with the hardware setup(Max232 chip,etc)
Even did a test program to blink an LED to check bootloader function.

However following the example in the book for LCDs (16f84) the LCD will
only display a solid black line. All connections have checked, rechecked
and then checked some more. Not a connection problem.

Here is the section that defines port/pins used for PIC to LCD.
Believe I has port A set to digital

Define LOADER_USED 1

Define LCD_DREG PORTA
Define LCD_DBIT 0
Define LCD_RSREG PORTA
Define LCD_RSBIT 4
Define LCD_EREG PORTB
Define LCD_EBIT 3
'Define LCD_BITS 4
'Define LCD_LINES 2
Define LCD_COMMANDUS 2000
Define LCD_DATA

' Allocate variables
command var byte ' Storage for command
i var byte ' Storage for loop counter
temp var word ' Storage for temperature
DQ var PORTB.7 ' Alias DS1820 data pin
DQ_DIR var TRISB.7 ' Alias DS1820 data direction pin

CMCON = 7'<===========BELEIVE THIS TURNS THE COMPATOR OFF!!

ADCON1 = 7 ' Set PORTA and PORTE to digital

Low PORTA.4 ' LCD R/W line low (W)
Pause 1000 ' Wait for LCD to start

Lcdout $fe, 1, "Temp in degrees C"' Display sign-on message


For some reason the "DEFINE" changed to "Define" when coping and pasting to
this post. In my code they are all capitol, etc "DEFINE"
What am I doing wrong.
Gordon

[Archangel]

Hello G-R-C,
the 16f88 has more going on than a 16f84. you need all 3 of these for this chip:
ADCON1 = 7 ' or ADCON1 = %00000111 'Disable A/D converter
ANSEL=%00000000 ' set all analog pins to digital
CMCON=7
Hope this helps
JS
edit: also look at this currant thread and follow the VB Highlighted tags.
http://www.picbasic.co.uk/forum/showthread.php?t=5646

[G-R-C]

Wow! Joe that was fast reply.

I'm going to try your suggestion right now. The

ANSEL=%00000000 ' set all analog pins to digital

is what I think is the missing piece.
Will let know how this goes.
Thanks for your help.
Gordon

[G-R-C]

Tried the

ANSEL=%00000000 ' set all analog pins to digital

still no luck. Just the solid black line across the
top of the LCD. Any other suggestions/ideas.

Thanks in advance.

[G-R-C]

Got going Joe.
Thanks for the tips and the link to the thread. Found it was a huge
help.

Thanks again, now I can move forward with this project.

[Archangel]

Hi Gordon,
It's like being married, it's not that you did anything wrong, maybe sometimes just not enough
I would add some housekeeping code like:

TrisA = %11110110    ' make port 0 and 4 outputs for lcd
TrisB = %11110000    ' make lower 4 bits outputs for lcd

I would add code to set the config fuses so as not to have to remember
when programming. I would temporaraly add an lcdout to run once at startup, something like:

start: ' this goes after your defines and adcon, ansel etc . . . 
Lcdout $fe, 1, "Gordon's Thermometer"
pause 1000

main:
all of your other code goes here


goto main
end

just to make sure the lcd is working and I would add a pause 1000 just before that to allow lcd time to initialize.
If you do not see the splash screen, you won't see anything else, and then you know to check wireing, contrast etc . . .

[savnik]

Low PORTA.4 ' LCD R/W line low (W)
Pause 1000 ' Wait for LCD to start

Delete the first line and add a pullup ressistor to RA4