Moving on to 18F series.

[Tina10]

I do not know if this has been discussed before but I could not find much information about it. I worked on 16F877A for sometime and know about setting fuses, initial registers, setting digital/analog i/o etc etc. I am having big problems understanding the setting up of 18F4550. Are there any guidance/notes anywhere which can make it a bit easier to understand for not so technically inclined. Datasheet seems to be a bit complicated at this stage. Thanks in advance.

[Demon]

Click on ADVANCED SEARCH at the top right of the forum.

- enter 18F4550 and CONFIG as keywords.
- select ANY DATE and AND NEWER in FIND POSTS
- click SEARCH NOW

There's a bunch of threads that discuss this issue, like this one:
http://www.picbasic.co.uk/forum/show...18F4550+config

Robert

[Tina10]

Thanks. Found some code relating to that.

DEFINE OSC 48
    @ __CONFIG   _CONFIG1L, _PLLDIV_1_1L & _CPUDIV_OSC1_PLL2_1L & _USBDIV_2_1L
    @ __CONFIG   _CONFIG1H, _FOSC_HSPLL_HS_1H
    @ __CONFIG    _CONFIG2H, _WDT_OFF_2H & _WDTPS_512_2H
    @ __CONFIG    _CONFIG3H, _PBADEN_OFF_3H & _MCLRE_OFF_3H 
    @ __CONFIG    _CONFIG4L, _LVP_OFF_4L & _ICPRT_OFF_4L &_XINST_OFF_4L

Opened the datasheet and tried hard so something enters my thick brain but
I want to ask:
What does _PLLDIV_1_1L mean? There are 3 fields PLLDIV0, PLLDIV1, PLLDIV2. If a 4MHz OSC is used, I guess these fields should be 000. What is PLL anyways? What is the difference between XT and XTPLL? If I am using XT OSC and a 4MHz crystal/resonator, and choose CPUDIV0/1 to be 00, does that mean the PIC will work at 4MHZ & NOT 4/4=1MHZ? If I do not want to use USB then what should be the setting? If I want to have an 8MHz oscillator which field should I change? Why on top it says DEFINE OSC 48 when the author used a 4MHz oscillator with the above settings?

I have many questions like this popping in my mind at this time, all I found is code but no explanation attached and even with datasheet, nothing is making perfect sense.

[mackrackit]

Take a look at the samples here
http://www.picbasic.co.uk/forum/show...8359#post68359
and look at section 2.3 in the data sheet.

PLL = Phase Lock Loop.

By using the PLL you can use a low speed external OSC and have the chip run at a higher speed. This is needed for USB but can also be used with out USB.

[Demon]

... Why on top it says DEFINE OSC 48 when the author used a 4MHz oscillator with the above settings?

I have many questions like this popping in my mind at this time, all I found is code but no explanation attached and even with datasheet, nothing is making perfect sense.

Very good question Tina. I wish I could give you a perfect answer 'cause I don't know myself without doing extensive SEARCHes on the forum. Here is a working example I use, as you can see, I leave myself a LOT of comments because I quickly forget what does what:

'***************************************************************************
'*  Name    : USBLabX1_RH.pbp                                              *
'*  Author  : Steve Monfette/Darrel Taylor/Demon                    *
'*  Date    : Jan 11 2012                                                  *
'*  Version : 3.0                                                          *
'*  Notes   : This is a re-creation of mister-e's USBdemo for DT_HID       *
'*          : Meant to work with mister-e's GUI                            *
'*          : Modified for Lab X1                                          *
'*  Hardware : PIC 18F4550, 20mhz crystal                                  *
'*           : Lab X1 Experimental Board                                   *
'*           : MeLabs U2 Programmer v4.32                                  *
'*  Software : PIC Basic Pro v2.60C                                        *
'*           : MicroCode Studio Plus v2.2.1.1                              *
'*           : MPASM WIN Assembler v4.02 (mplab tools/MPASM Suite)         *
'*  PIC mods : plastic USB connector hot-glued onto top of PIC             *
'*           : wires soldered directly to top of pins                      *
'*           : two 0.1uF ceramic caps in parallel across VUSB and VSS      *
'*           : D- wired to C4 (pin 23)                                     *
'*           : D+ wired to C5 (pin 24)                                     *
'***************************************************************************
'--- if you use these, you must comment the ones in the .inc file ---
@   __CONFIG    _CONFIG1L, _PLLDIV_5_1L & _CPUDIV_OSC1_PLL2_1L & _USBDIV_2_1L
@   __CONFIG    _CONFIG1H, _FOSC_HSPLL_HS_1H
@   __CONFIG    _CONFIG2L, _PWRT_OFF_2L & _BOR_ON_2L & _BORV_46_2L & _VREGEN_ON_2L
@   __CONFIG    _CONFIG2H, _WDT_OFF_2H
@   __CONFIG    _CONFIG3H, _CCP2MX_ON_3H & _PBADEN_OFF_3H & _LPT1OSC_OFF_3H & _MCLRE_ON_3H
@   __CONFIG    _CONFIG4L, _STVREN_ON_4L & _LVP_OFF_4L & _ICPRT_OFF_4L & _XINST_OFF_4L

DEFINE OSC 48

' Using only 4 bit bus to control LCD
DEFINE  LCD_DREG      PORTD         ' Set LCD data port
DEFINE  LCD_DBIT      4             ' Set starting data bit
DEFINE  LCD_RSREG     PORTE         ' Set LCD register select port
DEFINE  LCD_RSBIT     0             ' Set LCD register select bit
DEFINE  LCD_EREG      PORTE         ' Set LCD enable port
DEFINE  LCD_EBIT      1             ' Set LCD enable bit
DEFINE  LCD_BITS      4             ' Set LCD bus size
DEFINE  LCD_LINES     2             ' Set number of lines on LCD
define  LCD_COMMANDUS 2000          ' Set command delay time in microseconds
DEFINE  LCD_DATAUS    50            ' Set data delay time in microseconds

;--- Setup Interrupts ------------------------------------------------------
INCLUDE "DT_INTS-18.bas"        ; Base Interrupt System
INCLUDE "ReEnterPBP-18.bas"     ; PBP Re-entry for external interrupt

ASM
INT_LIST  macro    ; IntSource,     Label,   Type, ResetFlag?
        INT_Handler   USB_Handler
        INT_Handler   INT_INT,   _ToggleLED1, PBP,    yes
    endm
    INT_CREATE               ; Creates the interrupt processor
endasm

@   INT_ENABLE   INT_INT        ; enable external (INT) interrupts

;--- Setup USB -------------------------------------------------------------
INCLUDE "DT_HID260.pbp"

DEFINE USB_VENDORID    6017
DEFINE USB_PRODUCTID   2000
DEFINE USB_VERSION     1
DEFINE USB_VENDORNAME  "Mr E/DT/RH"
DEFINE USB_PRODUCTNAME "USBLabX1"
DEFINE USB_SERIAL      "001"
DEFINE USB_INSIZE      8    ;  IN report is PIC to PC (8,16,32,64)
DEFINE USB_OUTSIZE     8    ; OUT report is PC to PIC
DEFINE USB_POLLIN      10   ; Polling times in mS, MIN=1 MAX=10
DEFINE USB_POLLOUT     10

; --- Each USB status LED is optional, comment them if not used ------------
; --- They can be assigned to any pin, and no further action is required --- 
DEFINE USB_LEDPOLARITY 1       ; LED ON State [0 or 1]  (default = 1)
DEFINE USB_PLUGGEDLED  PORTD,0 ; LED indicates if USB is connected
DEFINE USB_TXLED       PORTD,1 ;  "      "     data being sent to PC
DEFINE USB_RXLED       PORTD,2 ;  "      "     data being received from PC

;--- Setup ADC -------------------------------------------------------------
DEFINE ADC_BITS 8  ; Number of bits in ADCIN result

    TRISA = %00000011               ' Set port A pins to 6 output, 2 input
    TRISB = %00001111               ' Set port B pins to 4 output, 4 input
                                    ' B0 = External Interrupt
    TRISC = %00000000               ' Set all port C pins to output
    TRISD = %00000000               ' Set all port D pins to output
    TRISE = %00000000               ' Set all port E pins to output
;OUTPUT PORTC.1
;OUTPUT PORTC.2
;--- Initialize ------------------------------------------------------------
;CCPR1L = 0
;CCPR2L = 0
;CCP1CON =   %00001100       ' CCP1, PWM mode
;CCP2CON =   %00001100       ' CCP2, PWM mode
;PR2     =   249             ' 0-1000 duty range
;T2CON   =   %00000101       ' TMR2 on, prescaler 1:4

    ADCON2.7 = 0       ; left justify    (Change this if ADFM in diff register)
    ADCON1 = %00001101     ; A/D Control
'       Bit 7,  0 = n/a
'       Bit 6,  0 = n/a
'       Bit 5,  Vref- Source
'               0 = VSS
'               1 = Vref- (AN2)
'       Bit 4,  Vref+ Source
'               0 = VSS
'               1 = Vref+ (AN3)
'       Bit 3-0 1111 = All digital
'               1110 = All digital, AN0 analog
'               1101 = All digital, AN0 & AN1 analog

    INTCON2 = %00000000
'       Bit 7, 0 = enabled, Pull-up resistors
'       Bit 6, 0 = falling edge, B0 interrupt
'       Bit 5, 0 = falling edge, B1 interrupt
'       Bit 4, 0 = falling edge, B2 interrupt
'       Bit 3, 0 = n/a
'       Bit 2, 0 = low priority, TMR0 interrupt
'       Bit 1, 0 = n/a
'       Bit 0, 0 = low priority, Port B on-change

;--- Variables -------------------------------------------------------------
Value0      VAR  WORD : Value0 = 0
Value1      VAR  WORD : Value1 = 0
DUTY1       VAR  WORD
DUTY2       VAR  WORD
'Old_PORTA   VAR  BYTE
'New_PORTA   VAR  BYTE
LED1        VAR PORTD.3
WS_CHAR     VAR BYTE
WS_BYTE     VAR BYTE
WS_LOOP     VAR WORD

    PORTB = %00000000               ' Set output on keypad
                                    '   to prevent floating pins

    FOR WS_LOOP = 0 to 1000         ' Wait for PIC and LCD to stabilize
        PAUSE 1
    NEXT WS_LOOP
'    LCDOUT  $FE,1,"Initializing..."
'    PORTD = 0                       ' Clear LEDs from LCD operations
'    FOR WS_LOOP = 0 to 500          ' Wait for LCD to initialize
'        PAUSE 1
'    NEXT WS_LOOP

    LCDOUT  $FE,1,"LabX1 18F4550 USB"
    FOR WS_LOOP = 0 to 100          ' Short delay to process LCD operation
        PAUSE 1
    NEXT WS_LOOP
    PORTD = 0                       ' Clear LEDs from LCD operations

    ARRAYWRITE USBTXBuffer, ["Lab X1  "]
    IF Plugged THEN GOSUB DoUSBOut     ; only send when USB is connected
    FOR WS_LOOP = 0 to 500          ' Short delay to process USB operation
        PAUSE 1
    NEXT WS_LOOP
    ARRAYWRITE USBTXBuffer, [Value0, Value1, PORTD.3, 0, 0, 0, 0, 0]
    IF Plugged THEN GOSUB DoUSBOut     ; only send when USB is connected
    
;--- The Main Loop ---------------------------------------------------------
Main:
    FOR WS_LOOP = 0 to 1000            ; Check for incomming USB data while waiting
@       ON_USBRX_GOSUB  _HandleRX
        PAUSE 1
    NEXT WS_LOOP
    
    ADCIN 0, Value0            ; Send A/D about once/sec
    ADCIN 1, Value1
    ARRAYWRITE USBTXBuffer, [Value0, Value1, PORTD.3, 0, 0, 0, 0, 0]
    IF Plugged THEN GOSUB DoUSBOut     ; only send when USB is connected

    GOTO Main
end

;---- Receive incoming data PORTB LEDS and CCP PWM dutycycle ---------------
HandleRX:
    ARRAYREAD  USBRXBuffer,[WS_BYTE, DUTY1.LowByte, DUTY1.HighByte, _
                                    DUTY2.LowByte, DUTY2.HighByte]
    LCDOUT  $FE,$C0,BIN WS_BYTE
    FOR WS_LOOP = 0 to 100          ' Short delay to process LCD operation
        PAUSE 1
    NEXT WS_LOOP
    PORTD = 0                       ' Clear LEDs from LCD operations
;    CCP1CON.5=DUTY1.1       ' load CCP1 duty value            
;    CCP1CON.4=DUTY1.0       '      with Duty1 
;    CCPR1L=DUTY1>>2         '
;    
;    CCP2CON.5=DUTY2.1       ' load CCP2 duty value            
;    CCP2CON.4=DUTY2.0       '      with Duty2
;    CCPR2L=DUTY2>>2         '
return

'---[INT - interrupt handler]---------------------------------------------------
ToggleLED1:
    TOGGLE LED1
    ARRAYWRITE USBTXBuffer, ["Button  "]
    IF Plugged THEN GOSUB DoUSBOut     ; only send when USB is connected
    PORTB = 0               ' Set output on keypad to prevent floating pins
    FOR WS_LOOP = 0 to 250          ' Very basic debounce for keypress
        PAUSE 1
    NEXT WS_LOOP
@ INT_RETURN

I hope the formattting doesn't get all screwed up.

Robert


EDIT: This code is 99.9% stable. USB is a bit unstable because I am using external power source, PIC datasheet explains how to wire properly. I didn't have proper parts, I just wanted to have "something" that worked so I could get CONFIG set up and PIC would talk with PC.

PWM stuff is commented out, I didn't need it. Extra displays to LCD also commented out (I was debugging USB problem).

Small debounce loop at bottom is not a good idea, I will rewrite that later. PAUSE could "potentially" screw up USB interrupt, I think.

[Darrel Taylor]

Long pauses are OK when you are using DT_HID260.pbp.

[Fujimanme]

The best advice is to download the latest data sheet for your PIC, grab a highlighter, check what features are available.
Then check the appropriate section, and change the registers as needed.
For example, your 18F4550 has a potential 13 ADC Ports.
If you look on pg 262, of the current data sheet, ADCON1 = $F '(%00001111) setting will turn all your ADC ports into Digital.

Unfortunately I don't know of any list that will clearly show all available.

If you are having difficulties, post your code, and someone can point you in the right direciton.

I do not know if this has been discussed before but I could not find much information about it. I worked on 16F877A for sometime and know about setting fuses, initial registers, setting digital/analog i/o etc etc. I am having big problems understanding the setting up of 18F4550. Are there any guidance/notes anywhere which can make it a bit easier to understand for not so technically inclined. Datasheet seems to be a bit complicated at this stage. Thanks in advance.