Newhaven 4x40 LCD, issues!

[mackrackit]

R/W goes to VSS.

8 bit is a tad faster by the math but I do not think it is humanly noticeable. I never use 8 bit as pins get ...expensive...

[Christopher4187]

Are you sure the R/W pin goes to ground? DT's program and the datasheet both show that R/W gets connected to the PIC. I ask because I'm not getting anything on the screen. DT's programs seems to have complied just fine, although I'm not sure if I did everything correctly.

[mackrackit]

Not sure where you saw Darrel connecting RW to the PIC, in fact he says not to in this post.
http://www.picbasic.co.uk/forum/show...=2388#post2388

The R/W pin is exactly what it says Read/Write, with 0 being Write.

Do you have the contrast pin connected to a pot as recommended? That is the most common problem. That should be pin #3 on the display. Not sure why the data sheet does not so it. Got to have contrast control.

[Christopher4187]

Sorry, it wasn't Darrell. It was NavMicroSystems in this picture. Anyhow, I literally get nothing. I can't even see the screen flicker. I've verified it has 4.8V at the power input and I've tried using a pot to adjust the contrast. I've only used serial LCD's from SEETRON in the past so this is new to me. Is there a basic way to test the screen? Like applying power to the LCD and +5 to another pin will display something?

[mackrackit]

I do not know of a test.
Post your code and connections/schematic.
Maybe we will be able to see the problem.

[Christopher4187]

Here is what I have:

DEFINE OSC 20
@ __CONFIG _CONFIG1L, _PLLDIV_5_1L & _CPUDIV_OSC1_PLL2_1L & _USBDIV_2_1L
@ __CONFIG _CONFIG1H, _FOSC_HSPLL_HS_1H & _FCMEN_OFF_1H & _IESO_OFF_1H
@ __CONFIG _CONFIG2L, _PWRT_OFF_2L & _BOR_OFF_2L & _BORV_3_2L & _VREGEN_ON_2L
@ __CONFIG _CONFIG2H, _WDT_OFF_2H & _WDTPS_32768_2H 
@ __CONFIG _CONFIG3H, _CCP2MX_ON_3H & _PBADEN_OFF_3H & _LPT1OSC_OFF_3H & _MCLRE_ON_3H
@ __CONFIG _CONFIG4L, _STVREN_ON_4L & _LVP_OFF_4L & _ICPRT_ON_4L & _XINST_OFF_4L


loopcount var word
;----[ Change these to match your LCD ]--------------------------------------- 
LCD_DB4    VAR PORTE.1 
LCD_DB5    VAR PORTA.3 
LCD_DB6    VAR PORTA.4 
LCD_DB7    VAR PORTE.2
LCD_RS     VAR PORTD.3 
LCD_E      VAR PORTA.5 
LCD_Lines  CON 2 ' # of Lines on LCD, 1 or 2 (Note: use 2 for 4 lines) 
LCD_DATAUS CON 50 ' Data delay time in us 
LCD_COMMANDUS CON 2000 ' Command delay time in us 
INCLUDE "LCD_AnyPin.pbp" ; *** Include MUST be AFTER LCD Pin assignments ****
; 
;----[ Your Main program starts here ]---------------------------------------- 
'LoopCount VAR WORD PAUSE 500 : LCDOUT $FE,1 : PAUSE 250 ; Initialize LCD (You may not need this, ; but some displays are picky) 
;
Main: LCDOUT $FE,1 ; clear screen 
LCDOUT $FE,$87,"Hello,",$FE,$C8,"From DT!" 
;
FOR LoopCount = 0 TO 65535 
    LCDOUT $FE,$80, IDEC LoopCount 
    LCDOUT $FE,$C0, IHEX4 LoopCount 
NEXT LoopCount 
GOTO Main

Pin connections are as follows:


1 VSS
2 VDD
3 10K POT
4 PORTD.3
5 VSS
6 PORTA.5
7 N/C
8 N/C
9 N/C
10 N/C
11 PORTE.1
12 PORTA.3
13 PORTA.4
14 PORTE.2
15 N/C
16 N/C

[mackrackit]

Did you turn the ADC off someplace ?