16F872 and LCD

[Fredrick]

How do i know the right pins i should connect my LCD display to? or can i select my own pins in my program?

[mister_e]

The manual show the default connections. You can also select your own and add some DEFINEs at the top of your program.

    '
    '    LCD setup
    '    =========
DEFINE LCD_DREG PORTB     ' LCD data port
DEFINE LCD_DBIT 0         ' LCD data starting bit
DEFINE LCD_RSREG PORTB    ' LCD register select port
DEFINE LCD_RSBIT 4        ' LCD register select bit
DEFINE LCD_EREG PORTB     ' LCD enable port
DEFINE LCD_EBIT 5         ' LCD enable bit
DEFINE LCD_BITS 4         ' LCD data bus size
DEFINE LCD_LINES 2        ' Number lines on LCD
DEFINE LCD_COMMANDUS 2000 ' Command delay time in us
DEFINE LCD_DATAUS 50      ' Data delay time in us

[Fredrick]

But the manual doese´t shows the default connections for 16F872, what are the defaults for my PIC?

Can i want use RB1 to RB6 insted och the default or does i have to use pin´s from outher ports?

btw why does the PIC have diffrent ports like PORTA, PORTB, PORTC..

And yes i´m new to PIC programing and i have just get my LED to blink when i push a button

[mister_e]

But the manual doese´t shows the default connections for 16F872, what are the defaults for my PIC?

Don't worry, the default one are the same for all PIC model.

Can i want use RB1 to RB6 insted och the default or does i have to use pin´s from outher ports?

Not sure what you mean

[skimask]

But the manual doese´t shows the default connections for 16F872, what are the defaults for my PIC?

Actually the manual does show the default connections.......for all PICs!
If you don't redefine the pins, they'll default to what the manual says, so long as those pins actually exist.

Can i want use RB1 to RB6 insted och the default or does i have to use pin´s from outher ports?

In a roundabout way, you can use any pin you want (using DT's ANYPIN routines) for the LCDIN/LCDOUT commands, but I'm guessing that's probably a bit above your skill at the moment. Give it time and anything is possible.

btw why does the PIC have diffrent ports like PORTA, PORTB, PORTC..

I suppose they could name them anything they want, just call them 1 thru 30, or A-Z or whatever.
But, since the PIC16F872 is primarily an 8bit device, it therefore makes a bit more sense to divide up the pins into 8 bit chunks as much as possible to keep the firmware/instructions/etc a bit simpler.
Quite frankly, you won't see a lot of 6 bit or 13 bit devices out there, or some other off the wall number. Pretty much everything is either 1,4,8, or 16 bits (yes, there are exceptions to the rule, just not a lot).

And yes i´m new to PIC programing and i have just get my LED to blink when i push a button

Get on it! Make 2 LEDs blink with 3 buttons... Then make a servo move with the buttons, then make a .... see how it goes?

Get out while you can! It's a never ending cycle man!!! You'll end up spending all of your money on the latest greatest thing out there!!! Blowing all of your sleep time programming PICs... Lose your money, house, sanity...it's like drugs! It's terrible!!!

Ok, not really...but you get the point...(as for me, I'll never learn!)

[Fredrick]

Hello.

Now i have connected the LCD as PBP defaults and when i run the PIC with this code the display shown the temerature for 1sec and then it shows "fffffffffffffffffffffff" on both lines for a sec and then shows the temerature again and so on...

Why?

' One-wire temperature for LAB-X1 and DS1820
define OSC 20
DEFINE LCD_COMMANDUS 2000
DEFINE LCD_DATAUS 600

temperature Var	Word			' Temperature storage
count_remain Var Byte			' Count remaining
count_per_c Var	Byte			' Count per degree C

pause 1000


DQ	Var	PORTB.2			' One-wire data pin

	ADCON1 = 7			' Set PORTA and PORTE to digital

mainloop: OWOut DQ, 1, [$CC, $44]       ' Start temperature conversion

waitloop: OWIn DQ, 4, [count_remain]	' Check for still busy converting
	
    If count_remain = 0 Then waitloop

	OWOut DQ, 1, [$CC, $BE]		' Read the temperature
    OWIn DQ, 0, [temperature.LOWBYTE, temperature.HIGHBYTE, Skip 4, count_remain, count_per_c]

	' Calculate temperature in degrees C to 2 decimal places (not valid for negative temperature)
	temperature = (((temperature >> 1) * 100) - 25) + (((count_per_c - count_remain) * 100) / count_per_c)
	Lcdout $fe, 1, DEC (temperature / 100), ".", DEC2 temperature, " C"

	' Calculate temperature in degrees F to 2 decimal places (not valid for negative temperature)
	temperature = (temperature */ 461) + 3200
	Lcdout $fe, $c0, DEC (temperature / 100), ".", DEC2 temperature, " F"

    Pause 1000                      ' Display about once a second

	Goto mainloop			' Do it forever

[Acetronics2]

Hi,

Try this for Waitloop ...

'*****************************************************************************
' Check for still busy converting ( ~ 4500 fois ... )
'*****************************************************************************

waitloop: 

		INPUT DQ
		If NOT DQ Then waitloop

AND ....

DEFINE LCD_DATAUS 600

Should be ...

DEFINE LCD_DATAUS 60

Alain