Pic18F452

[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