PIC18F4620 Troubles

[CluckShot]

I am taking the standard program to demo the PIC16F877A as a clock and starting to branch out leaning as I go. Sorry if I am just leaning but I could really use some help The problem obviously is in configuration of the ports and interrupts.

Since the PIC18F4620 has several timers rather than the one of the PIC16F877A I assume that some sort of configuration for setting the interrupts on should be done differently but I am not entirely able to get this down. Chalk it up to learning but I need some help on this one.

I will include my defines and the settings and what should be printing out. The rest of the program really is quite generic.

Defines --
Define LCD_DREG PORTD ' Define LCD connections
Define LCD_DBIT 4
Define LCD_RSREG PORTE
Define LCD_RSBIT 0
Define LCD_EREG PORTE
Define LCD_EBIT 1
ADCON1 = 7 ' PORTA and E digital
Low PORTE.2 ' LCD R/W low = write

' Set TMR0 to interrupt every 16.384 milliseconds
T0CON.7 = 1 ' Set Timer0 on!
T0Con.6 = 0 ' Set as a 16 bit timer/counter
T0Con.5 = 0 ' Set the internal clock active
T0Con.4 = 0 ' Set Source edge bit = low to high on T0CLKI pin
T0Con.3 = 1 ' Bypass the prescaler (Revisit this one!)
T0Con.2 = 0 ' Prescaler settings
T0Con.1 = 0
T0Con.0 = 0
TRISD = %11111111

'PSPCON = 0
'OPTION_REG = $88 ' Set TMR0 configuration and enable PORTB pullups
Enable interrupt ' Enable TMR0 interrupts
'INTCON =
On Interrupt Goto tickint

-===

If you go to the standard clockx example on the melabs site you get the rest of the code, I really don't expect it to be of much interest.


My issue is that the system has an led that flashes with each interrupt and it appears to be working just fine. The problem is that the LCDOUT writing per this program is not working. It works just fine with the PIC16F877A chip.

Help Please

[mister_e]

Hi and welcome on the forum.

Try to change ADCON1=7 to ADCON1=$0F.

[CluckShot]

First Thanks!

Next I will try your solution and report the results and report if there are any problems.

Finally: Please tell me why this should work. In trying to read all the fun stuff down in the chip technical papers I must be missing something and I definitely want to be more astute as to why as well as how.

Thanks again
Paul

[ra68gi]

Defines --
Define LCD_DREG PORTD ' Define LCD connections
Define LCD_DBIT 4
Define LCD_RSREG PORTE
Define LCD_RSBIT 0
Define LCD_EREG PORTE
Define LCD_EBIT 1
ADCON1 = 7 ' PORTA and E digital
Low PORTE.2 ' LCD R/W low = write


Help Please

Try adding "Define LCD_BITS 4 " to your defines.

Regards
Raghunathan.

[Pic_User]

First Thanks!

Next I will try your solution and report the results and report if there are any problems.

Finally: Please tell me why this should work. In trying to read all the fun stuff down in the chip technical papers I must be missing something and I definitely want to be more astute as to why as well as how.

Thanks again
Paul

Hi Paul,
To find out more about mister_e’s helpful answer, you can use, the forum search engine, to look for:
ADCON1=$0F

The data sheets can be searched the same way.

-Adam-

[mister_e]

FYI, this DEFINE is the default one, if you don't write it yourself, PBP will do it for you in background.

Let's see what happen in the .LST file, i compile those lines...

Define LCD_DREG PORTD ' Define LCD connections
Define LCD_DBIT 4
Define LCD_RSREG PORTE
Define LCD_RSBIT 0
Define LCD_EREG PORTE
Define LCD_EBIT 1

LCDOUT "Hello"

Now, i open the .LST file, scroll to the end... and

LCD_BITS                          00000004
LCD_COMMANDUS                     000007D0
LCD_DATAUS                        00000032
LCD_DBIT                          4
LCD_DREG                          PORTD
LCD_EBIT                          1
LCD_EREG                          PORTE
LCD_LINES                         00000002
LCD_RSBIT                         0
LCD_RSREG                         PORTE
LCD_RWBIT                         00000000
LCD_RWREG                         00000009

everything is there. Now what happen, if i don't use any DEFINE

lcdout "Hello"

.LST

LCD_BITS                          00000004
LCD_COMMANDUS                     000007D0
LCD_DATAUS                        00000032
LCD_DBIT                          00000000
LCD_DREG                          00000005 
LCD_EBIT                          00000003
LCD_EREG                          00000006
LCD_LINES                         00000002
LCD_RSBIT                         00000004
LCD_RSREG                         00000005
LCD_RWBIT                         00000004
LCD_RWREG                         00000005

Interesting eh! But i agree, it's always nice to have ALL DEFINE in your code, so if one day you decide to change them, it's just easy. PICMultiCalc also generate those.. kinda lazy stuff... and some day i am

---------------------------------------

Finally: Please tell me why this should work. In trying to read all the fun stuff down in the chip technical papers I must be missing something and I definitely want to be more astute as to why as well as how.

Well, why ADCON1 would have to work? Where did you get this value ?

Let's see a datasheet snip...
<IMG SRC="http://www.picbasic.co.uk/forum/attachment.php?attachmentid=1634&stc=1&d=117924073 8">

ADCON1=7 set PCFG3:PCFG0 to 0111.. right? If so, what happen to AN0,1,2,3,4,5,6,7 ?

ADCON1=$0F set PCFG3:PCFG0 to 1111.. right? If so, what happen to AN0,1,2,3,4,5,6,7,8,9,10,11,12 ?

I think it's the explanation :-)

EDIT: Sorry PicUser.. we write at the same time !

[CluckShot]

You confirmed my research and it is always nice to have someone back up your thinking. It either means that the both of you are lost ... (not in this case) or that you actually understand what the other person is saying. (something nice)

In any case thanks so much and I am sure I will be back and hopefully I will have nice helpful things for others as well.

Paul