Pic18F452

[TonyCNC]

Hi Melanie my lcd defines are:
DEFINE LCD_BITS 4
DEFINE LCD_LINES 2
DEFINE LCD_DREG PORTD
DEFINE LCD_DBIT 0
DEFINE LCD_RSREG PORTE
DEFINE LCD_RSBIT 0
DEFINE LCD_EREG PORTE
DEFINE LCD_EBIT 1
DEFINE LCD_RWREG PORTE
DEFINE LCD_RWBIT 2

[MikeTamu]

If you look at the datasheet, you can see that PortE, bit 0,1, and 2 are all Analog ports. So what is most likely happening, is that the PIC is in analog mode for these pins and not giving you digital outputs.

Put this in your code before the DEFINES:

ADCON1.3=0
ADCON1.2=1
ADCON1.1=1
ADCON1.0=0

These 4 lines will make all of your analog pins into digital pins. If you need to use some of your digital pins as analog ones, then just change these 4 bits according to the table in the datasheet referenced below.

To see how I came to this, look at page 182 (184 of pdf) in the PIC 18f452 datasheet.

[TonyCNC]

Thank you very much MikeTamu i just assumed that PBP took care of all that for me as there is no reference to it in the pbp manual.

Thanks again.

[charudatt]

I am having similar problems trying to get an LCD working on EasyPIC3 from Mikroelectronika Board using PBP and 18F452 MCU. Although i can get the LED to blink , I cannot get the LCD to work. Can you help.

EasyPIC3 Development Board Configuration -
D4 - RB4
D5 - RB5
D6 - RB6
D7 - RB7
RS - RB2
E - RB3
RW - GND

My Code:

DEFINE OSC 8

' HARDWARE DEFINES
'-----------------------------------------------------------------
' Define LCD pins

DEFINE LCD_BITS 4
DEFINE LCD_LINES 2
DEFINE LCD_DREG PORTB
DEFINE LCD_DBIT 4
DEFINE LCD_RSREG PORTB
DEFINE LCD_RSBIT 2
DEFINE LCD_EREG PORTB
DEFINE LCD_EBIT 3

'-----------------------------------------------------------------
TRISA = %111111 'INITIALIZE PORT DIRECTIONS
TRISB = %00000000
TRISC = %10101001
TRISD = %00000011
TRISE = %00000111
Adcon1 = 7 ' Set PORTA DIGITAL
INTCON2.7=1 ' DISABLE Pull-Up's
'-----------------------------------------------------------------
PAUSE 500

Lcdout $fe , 1 , "EasyPIC3 DEV"
LCDOut $FE,$C0, "Board v1A"
PAUSE 2000

END

[mister_e]

Be sure you set HS_OSC fuse before programming your PIC

[charudatt]

Hello,

Thanks for coming to my help once again, yes the Crystal fuse is set properly as i have a small led blink rotuine after this display , which works properly.

The LCD works with MikroBasic Compiler, But does not come on with PBP.

[paul borgmeier]

Because you are running at 8MHz, try including one or both of these and increasing the times as shown here

DEFINE LCD_COMMANDUS 4000
DEFINE LCD_DATAUS 100

[Lotondo]

If you look at the datasheet, you can see that PortE, bit 0,1, and 2 are all Analog ports. So what is most likely happening, is that the PIC is in analog mode for these pins and not giving you digital outputs.

Put this in your code before the DEFINES:

ADCON1.3=0
ADCON1.2=1
ADCON1.1=1
ADCON1.0=0

These 4 lines will make all of your analog pins into digital pins. If you need to use some of your digital pins as analog ones, then just change these 4 bits according to the table in the datasheet referenced below.

To see how I came to this, look at page 182 (184 of pdf) in the PIC 18f452 datasheet.

Thanks for the clear explanation !
As you said this will turn all 8 pins into digital.
Would it be possible to get AN0 and AN1 digital and all the others (AN2 to AN7) analog ?
It's still unclear in this case what's ADCON0 for !
Thanks for clearing me out.
Lotondo

[mister_e]

Hava a look in the datasheet, register 17-2, PDF page 184

<img SRC="http://www.picbasic.co.uk/forum/attachment.php?attachmentid=1361&stc=1&d=117069960 6">

[Lotondo]

Thanks Mr E
clear enough.
I believe it's not possible to set the pins like I said
Could you pls. tell me something more about ADCOM0.
Datasheets are useful but something they are a little
too complicate if you are not full into the subject.
Thanks
Lotondo

[mister_e]

I can't tell anything about ADCOM As it doesn't exist, but let's try with ADCON0

If you plan to use PBP ADCIN, use my PicMultiCalc software. It make things easy. Let's say your OSC=20 MHz, your analog source impedance is 1K and you want to make a 10 Bit conversion, you need to add those DEFINEs at the top of your code

DEFINE ADC_BITS 10    ' ADCIN resolution  (Bits)
DEFINE ADC_CLOCK 2    ' ADC clock source  (Fosc/32)
DEFINE ADC_SAMPLEUS 3 ' ADC sampling time (uSec)

ADC_CLOCK 2 refer to ADCS1:ADCS0 bits (ADCON0<7:6>)

Sure you could even use the usual Frc and set your Sampling time to 50uSec and it will cover almost every possible situation.

Even by using the PicMultiCalc, you'll need to set the ADFM bit in ADCON1 register. Yeah i didn't include this in the software as Microchip change their mind in almost every new PIC. Maybe One day... maybe.

[mister_e]

Now, if you plan to NOT use ADCIN, you must do everything manually. Here's ashort example... OK OK it looks huge but...

        '
        '   PIC configuration fuses
        '   ========================
        asm
		__CONFIG    _CONFIG1H, _HS_OSC_1H
                                ; HS osc (20 MHz
                                ;		                          
		__CONFIG    _CONFIG2L, _BOR_ON_2L & _BORV_27_2L & _PWRT_ON_2L 
                                ; Enable Brown out voltage detect
                                ; Brown out voltage threshold 2.7 Volt
                                ;
		__CONFIG    _CONFIG2H, _WDT_OFF_2H
                                ; Disable watch dog timer
                                ;
		__CONFIG    _CONFIG3H, _CCP2MX_OFF_3H
                                ; Use default PORTC.1 for CCP2
                                ;
		__CONFIG    _CONFIG4L, _STVR_ON_4L & _LVP_OFF_4L & _DEBUG_OFF_4L
                                ; enable stack overflow
                                ; disable low-voltage programming mode
                                ; disable background debugger		  
                                ;
		__CONFIG    _CONFIG5L, _CP0_OFF_5L & _CP1_OFF_5L & _CP2_OFF_5L & _CP3_OFF_5L 
                                ; disable code protect (user block)
                                ;		                          
		__CONFIG    _CONFIG5H, _CPB_OFF_5H & _CPD_OFF_5H
                                ; disable code protect (boot block)
                                ;		
		__CONFIG    _CONFIG6L, _WRT0_OFF_6L & _WRT1_OFF_6L & _WRT2_OFF_6L & _WRT3_OFF_6L       
                                ; disable write protect (user block)
                                ;		                      
		__CONFIG    _CONFIG6H, _WRTC_OFF_6H & _WRTB_OFF_6H & _WRTD_OFF_6H
                                ; disable Write protect CONFIG regs 
                                ; disable write protect boot block
                                ; disable rite protect Data EE
                                ;
		__CONFIG    _CONFIG7L, _EBTR0_OFF_7L      
                                ; Disable table Read protect user block
                                ;
		__CONFIG    _CONFIG7H, _EBTRB_OFF_7H
                                ; Disable Read protect boot block enable
        endasm
                
        '
        '       Hardware configuration
        '       ======================
                '
        DEFINE OSC 20
                '
                '   Adc
                '   ---
        ADCON0 = %10000001                  ' Conversion clock = Fosc/32             
                                            ' AN0 selected   
                                            ' turn on ADC

        ADCON1 = %110001110                 ' right justified results
                                            ' Conversion clock = Fosc/32
                                            ' PORTA.0 as analog, all other to digital
        '
        '       Hardware assignment
        '       ===================
                '
                '   LCD
                '   ---
        DEFINE LCD_DREG PORTD               ' LCD data port 
        DEFINE LCD_DBIT 4                   ' LCD data starting bit 0 or 4 
        DEFINE LCD_RSREG PORTD              ' LCD register select port 
        DEFINE LCD_RSBIT 2                  ' LCD register select bit 
        DEFINE LCD_EREG PORTD               ' LCD enable port 
        DEFINE LCD_EBIT 3                   ' LCD enable bit 
        DEFINE LCD_BITS 4                   ' LCD bus size 4 or 8 
        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 

        '
        '       Alias definition
        '       ================
                '
                '   ADC
                '   ---
        GoDone  var ADCON0.2                ' use to start/stop/check 
                                            '       AD conversion
                                            
        ADON    VAR ADCON0.0                ' use to start/shut-off ADC

        '
        '       Variable definition
        '       ===================
        @AdResult = ADRESL    
        AdResult        var word EXT        ' Store ADC result
        
        '
        '       Software constants
        '       ==================
        ADC_SampleUs    con 3               ' ADC sampling time        
        
        '
        '       Program Start here
        '       ==================
        Pause 500                           ' LCD start up delay

Start:
                '
                '       A/D conversion
                '       --------------
        adon = 1                            ' turn on ADC
        pauseus adc_sampleus                ' Wait minimum sampling time
        godone = 1                          ' start conversion
        while godone : wend                 ' check if finished
                                            '
        adon = 0                            ' turn off ADC
                '
                '       Show result on LCD
                '       ------------------
        lcdout $FE,1, "Result=:", dec adresult 
                                            ' show result on LCD
        pause 250
        goto stART