LAB-XUSB Experimenter Board help

[ERMEGM]

Hello,

I bought the following product and am trying to run a sample program on it provided by their website. I have a PIC16F874A installed and can't seem to get the sample programs to work. All I get is a single row of solid blocks on the LCD.

Here is the original code:

' PICBASIC PRO program to display key number on LCD

' Define LOADER_USED to allow use of the boot loader.
' This will not affect normal program operation.
Define	LOADER_USED	1

' RESET_ORG can be set to move the BASIC program out of the way
' of any boot loader running from location 0, such as the
' Microchip USB boot loader
'Define	RESET_ORG	800h

Define	OSC	48		' Core is running at 48MHz

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


' Define program variables
col     var     byte            ' Keypad column
row     var     byte            ' Keypad row
key     var     byte            ' Key value


        INTCON2.7 = 0		' Enable PORTB pullups
        ADCON1 = 15		' Make PORTA and PORTE digital
        Low PORTE.2             ' LCD R/W low (write)
        Pause 100               ' Wait for LCD to start

        Lcdout $fe, 1, "Press any key"  ' Display sign on message

loop:   Gosub getkey            ' Get a key from the keypad
        Lcdout $fe, 1, #key     ' Display ASCII key number
        Goto loop               ' Do it forever


' Subroutine to get a key from keypad
getkey:
        Pause 50                ' Debounce

getkeyu:
        ' Wait for all keys up
        PORTB = 0               ' All output pins low
        TRISB = $f0             ' Bottom 4 pins out, top 4 pins in
        If ((PORTB >> 4) != $f) Then getkeyu    ' If any keys down, loop

        Pause 50                ' Debounce

getkeyp:
        ' Wait for keypress
        For col = 0 to 3        ' 4 columns in keypad
                PORTB = 0       ' All output pins low
                TRISB = (dcd col) ^ $ff ' Set one column pin to output
		Pauseus 1
                row = PORTB >> 4        ' Read row
                If row != $f Then gotkey        ' If any keydown, exit
        Next col

        Goto getkeyp            ' No keys down, go look again

gotkey: ' Change row and column to key number 1 - 16
        key = (col * 4) + (ncd (row ^ $f))
        Return                  ' Subroutine over

        End

Because PBP3 doesn't like it using the instruction Loop as a label, I changed it to Looper. Also changed INTCON2.7 = 0 to OPTION_REG.7 = 0 for the 874A and changed the define osc 48 to define osc 20.

I am new to this type of code and find it difficult to read, so the problem doesn't stand out for me. What I'm left with is this:

;----[16F874A Hardware Configuration]-------------------------------------------
#IF __PROCESSOR__ = "16F874A"
  #DEFINE MCU_FOUND 1
#CONFIG
cfg = _XT_OSC                 ; XT oscillator
cfg&= _WDT_OFF                ; WDT disabled
cfg&= _PWRTE_OFF              ; PWRT disabled
cfg&= _BODEN_OFF              ; BOR disabled
cfg&= _LVP_OFF                ; RB3 is digital I/O, HV on MCLR must be used for programming
cfg&= _CPD_OFF                ; Data EEPROM code protection off
cfg&= _WRT_OFF                ; Write protection off; all program memory may be written to by EECON control
cfg&= _DEBUG_OFF              ; In-Circuit Debugger disabled, RB6 and RB7 are general purpose I/O pins
cfg&= _CP_OFF                 ; Code protection off
  __CONFIG cfg

#ENDCONFIG

#ENDIF

;----[Verify Configs have been specified for Selected Processor]----------------
;       Note: Only include this routine once, after all #CONFIG blocks
#IFNDEF MCU_FOUND
  #ERROR "No CONFIGs found for [" + __PROCESSOR__ +"]"
#ENDIF

  define  osc 20                 ' Core is running at 20MHz

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


' Define program variables
  col     var     byte          ' Keypad column
  row     var     byte          ' Keypad row
  key     var     byte          ' Key value


        OPTION_REG.7 = 0	    ' Enable PORTB pullups
        ADCON1 = 15		        ' Make PORTA and PORTE digital
        Low PORTE.2             ' LCD R/W low (write)
        Pause 100               ' Wait for LCD to start

        Lcdout $fe, 1, "Press any key"  ' Display sign on message

looper: Gosub getkey            ' Get a key from the keypad
        Lcdout $fe, 1, #key     ' Display ASCII key number
        Goto looper             ' Do it forever


' Subroutine to get a key from keypad
getkey:
        Pause 50                ' Debounce

getkeyu:
        ' Wait for all keys up
        PORTB = 0               ' All output pins low
        TRISB = $f0             ' Bottom 4 pins out, top 4 pins in
        If ((PORTB >> 4) != $f) Then getkeyu    ' If any keys down, loop

        Pause 50                ' Debounce

getkeyp:
        ' Wait for keypress
        For col = 0 to 3        ' 4 columns in keypad
                PORTB = 0       ' All output pins low
                TRISB = (dcd col) ^ $ff ' Set one column pin to output
		Pauseus 1
                row = PORTB >> 4        ' Read row
                If row != $f Then gotkey        ' If any keydown, exit
        Next col

        Goto getkeyp            ' No keys down, go look again

gotkey: ' Change row and column to key number 1 - 16
        key = (col * 4) + (ncd (row ^ $f))
        Return                  ' Subroutine over

        End

Does anything jump out to anyone? I'm just playing with this board and am trying to get it to work. It says "PIC18F4550 recommended" but lists the 16F874 as a compatible chip. Thanks in advance.

Tony

Product in question
Schematic and code links

[Demon]

Lower case DEFINEs?

I can never remember when it's ok to use, so I always use upper case DEFINEs.

Robert

[Demon]

Also, I am not familiar with your chip. It should be good enough as long as you have the ports used in your code, as well as enough code space.

The 4550 is required if you want to use USB.

Robert

[Demon]

I just remembered, I have jumpers on my Lab X1. Have you checked if any on your Lab USB?

Robert

[rsocor01]

I think that you are missing the LCD_BITS and the LCD_LINES defines. Also, how do you have the pin Vo connected in your LCD?

[aerostar]

This
cfg = _XT_OSC ; XT oscillator

Should be
cfg = _HS_OSC

Check this syntax

[ERMEGM]

Well, changing the config did it, but only for the LCD sample program where it just repeats saying Hello World. On this key press program, I am getting mixed results. Sometimes it's a single line of blocks. Other times it's a cursor or 9 characters like arrow symbols and slashes. When I press a button, each one yields a ?. If I hit the reset button, those characters side step off of the lcd.

At one point, when I played with the power up and watchdog timers, I did get the words "press any key" however, several of the letters were missing.

The schematic of the board is available at the links provided. Nothing was changed, or requires to be changed on the jumpers. I have JP2 set to USB power instead of a wall wart.

The chip I have matches the pinout of the 4550 exactly, so the configuration should be the same. I thought buying the completed board and using the sample programs was going to be straight forward. Silly me.

[Scampy]

Well, changing the config did it, but only for the LCD sample program where it just repeats saying Hello World.

this is confusing - from what I can see the crystal on the board is 20 Mhz, but the OSC value in the first bit of code is 48 !

What happens if you change the OSC to 48 or 40 in your code ? - Also, comment out the section of the code that deals with the key pad and make the main loop a simple LCDout "hello world" - once you get that part running then you know you have the config and LCD setting right, and then you can un-comment the switch routines and debug them.

[towlerg]

this is confusing - from what I can see the crystal on the board is 20 Mhz, but the OSC
value in the first bit of code is 48

check out the fuses, PLL etc. 48Hhz is needed for USB

[ERMEGM]

It IS confusing. As I said, I made the change to the LCD program that just says Hello World over and over again, but it doesn't work on the keypad program.

I'm still learning this type of code, so the error could be right in front of me and I won't see it. That's why I'm asking for help deciphering this type of coding.

Thanks,
Tony

[Scampy]

check out the fuses, PLL etc. 48Hhz is needed for USB

But how would you get the timing right with a 20mhz crystal. I thought HS setting means that you run at the crystal speed, and the HS_PLL is typically a multiplier (of 4). IE to get 48 Mhz a 12 Mhz crystal is required, OSC is set to 48 and the fuse set to HS_PLL. - From the pictures of this LAB it's not clear if you can interchange the crystals, which is why I found that confusing.