LCDOUT with MPASWIN

[lerameur]

HI,

Cant seem to troubleshoot this problem. The LCD is showing random characters, This line
Lcdout "Right: ", Dec right
is showing right: XXXX ( The XXX are random characters)
Also sometime i turn on the circuit I only see the last few characters of the word 'Right' including the random characters...
Must be a timing, or clocking issue.
IM using microcode studio with MPASMWIN
any ideas?

Ken

INCLUDE "modedefs.bas" 'Includes supoprt for PicBasic language
 
OSCCON = %01110000 '8 Mhz
DEFINE OSC 8

CMCON = 7 : ANSEL = 0 : ADCON1 = 7
DEFINE LCD_DREG PORTB ' Set LCD Data port
DEFINE LCD_DBIT 4 ' Set starting Data bit (0 or 4) if 4-bit bus
DEFINE LCD_RSREG PORTB ' Set LCD Register Select port
DEFINE LCD_RSBIT 1 ' Set LCD Register Select bit
DEFINE LCD_EREG PORTB ' Set LCD Enable port
DEFINE LCD_EBIT 0 ' Set LCD Enable bit
DEFINE LCD_BITS 4 ' Set LCD bus size (4 or 8 bits)
DEFINE LCD_LINES 2 ' Set number of lines on LCD
DEFINE LCD_COMMANDUS 2500
DEFINE LCD_DATAUS 250
DEFINE CHAR_PACING 1000

' Define ADCIN parameters
Define ADC_BITS 10 ' Set number of bits in result
Define ADC_CLOCK 3 ' Set clock source (3=rc)
Define ADC_SAMPLEUS 50 ' Set sampling time in uS

ADCON1 = %11000001 ' Set PORTA analog and RIGHT justify result
ADCON0 = %00000001 ' Configure and turn on A/D Module

TRISB = 0
TRISA = 1

right var word : oldright var word 
right = 500
  
mainloop:

ADCON0.2 = 1 'Start Conversion
oldright = right 'Pot reading 1
ADCIN 0, right 'Read channel PORTA.0
pause 50

right = (right +oldright)/2 'Reducing the fluctuating output by taking an average


Lcdout $fe, 1 'Clear screen
Lcdout "Right: ", Dec right 'Display the decimal value
pause 100

goto mainloop
end

[HenrikOlsson]

Hi,
Verify that the PIC is running at the speed you think it is, otherwise the set timings will be wrong. If it IS running at 8MHz then try increasing the LCD_COMMANDUS and LCD_DATAUS defines.
I don't think MPASM has anything to do with it.

/Henrik.

[lerameur]

HI,
I changed the values for LCD_COMMANDUS and LCD_DATAUS but that did not change anything. How do I check internal oscillation ??

I also ADDED hpwm COMMAND and I get the oscillation output wanted, so I guess the clocking is good...

K

[Acetronics2]

150 ms between readings must be a bit tooshort to see anything clear ...

also add PAUSE > 700ms before sending the first data stream ( just once @ power up ) to the LCD ...

Alain

[lerameur]

I am down with just the LCDOUT commands:
still giving awkward letters on the LCD:

INCLUDE "modedefs.bas" 'Includes supoprt for PicBasic language

OSCCON = %01110000 '8 Mhz
DEFINE OSC 8

'/////////////////////////
'// LCD configuration //
'/////////////////////////

DEFINE LCD_DREG PORTB ' Set LCD Data port
DEFINE LCD_DBIT 4 ' Set starting Data bit (0 or 4) if 4-bit bus
DEFINE LCD_RSREG PORTB ' Set LCD Register Select port
DEFINE LCD_RSBIT 0 ' Set LCD Register Select bit
DEFINE LCD_EREG PORTB ' Set LCD Enable port
DEFINE LCD_EBIT 1 ' Set LCD Enable bit
DEFINE LCD_BITS 4 ' Set LCD bus size (4 or 8 bits)
DEFINE LCD_LINES 2 ' Set number of lines on LCD
DEFINE LCD_COMMANDUS 2500
DEFINE LCD_DATAUS 250
DEFINE CHAR_PACING 2000
pause 1000


Mainloop:

lcdout $FE,1, " This is a test" '
lcdout $FE,$C0, "Next or Select" '
pause 200

GOTO Mainloop
End

[Acetronics2]

a scheme would be helpful ... especially to see how contrast and R/W lines are connected ...