LCDOUT custom commands - how to?

[flotulopex]

So, the code looks like this now:

include "16F88-FUSES.BAS"

'PIC 16F88 - 4MHz

' LCD circuitery
'23,24,25,26,32,33,34,35,40 - Vdd (+5V)
'27,38  - Vss (GND)
'31 DB0 - PORTB.0
'30 DB1 - PORTB.1
'29 DB2 - PORTB.2
'28 DB3 - PORTB.3
'39 RS  - PORTB.4
'36 E   - PORTB.6
'37 R/W - PORTB.7

DEFINE LCD_DREG PORTB       'LCD data port 
DEFINE LCD_DBIT 0           'LCD data starting bit 0 or 4 
DEFINE LCD_RSREG PORTB      'LCD register select port 
DEFINE LCD_RSBIT 4          'LCD register select bit 
DEFINE LCD_EREG PORTB       'LCD enable port 
DEFINE LCD_EBIT 6           'LCD enable bit 
DEFINE LCD_RWREG PORTB      'LCD read/write port
DEFINE LCD_RWBIT 7          'LCD read/write 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


' Register settings
OSCCON     = %01100000      'Internal RC set to 4MHZ
ANSEL      = %00000000      'Disable Analogue Inputs
OPTION_REG = %01000000      'Enable PORTB pullups


ManualLCDInit:
    FLAGS=2  ' Void PBP lcd initialisation... it's a nice feature !!!
    PAUSE 500
    Lcdout $FE, $33
    Lcdout $FE, $33
    Lcdout $FE, $20 ' official 4 bit mode
    @  bsf LCD_EREG, LCD_EBIT
    PAUSEUS 20
    @  bcf LCD_EREG, LCD_EBIT
    Lcdout $FE, $28 ' Function Set
    Lcdout $FE, $14 ' Bias
    Lcdout $FE, $78 ' Contrast set
    Lcdout $FE, $5E ' Power/Icon/Contrast
    Lcdout $FE, $6A ' Follower control
    Lcdout $FE, $0C ' Display ON
    Lcdout $FE, $01 ' Clear display
    Lcdout $FE, $06 ' Entry mode Set
   ' --------------------------------- End LCD init!

    LCDOUT $FE,1,"Line1",$FE,$C0,"Line 2"
Pouet: 
    Goto Pouet

end

Guess what? The display still doesn't work.

I'm waiting for AE to give some answers...

At least, have a look at how the displays look like (they're only 2mm thick). Would be really nice if something could be written on it, no? (pin 21 is on the upper right corner looking at picture PICT0001small.JPG).

Keithdoxey, it's getting clearer to me. I have to grab a piece of paper and study a little. Thanks a lot since this is exactly the kind of information I was looking for.

[keithdoxey]

I use these to lines to make sure all the analog and comparator stuff is killed dead...

ANSEL = %00000000 ' Disable Analogue Inputs
CMCON = %00000111 ' Disable Comparators

Looking at your photos it looks as if Pin37 of the LCD R/W is connected via a blue/green wire to pin 13 of the PIC RB7. There also seems to be an additional brown wire flying off somewhere from this pin. Where does the other end of that connect to ?

Try with the R/W line connected directly to 0V as you only need to write to the PIC.

One other point... I suggested putting LEDs on the PIC and observing it counting up to ensure that the count operated correctly. You said that you tested the pins with a logic probe, presumabley one pin at a time just to observe the two different states.

The reason I suggested the LEDs is that when I first used a 16F88 I hadnt killed all the analogue bits properly and although I could turn an LED on on any pin, when I changed another pin the first LED would go out.

The reason being that updating a pin involves reading the port register for the existing values, modifying it and writing it back. If any analogue stuff is still enabled the pin reads as a zero and will get set to zero even though it was previously a one.

Do you have access to a "normal" HD44780 display of any size just to test that your PIC is correctly configured. From what I have seen so far there shouldt be any real problems getting this display to work as it is 44780 compatible. If you try with a normal display and it still doesnt work then something isnt right with the PIC. Once you have that working it should just be a matter of swapping the displays.

[flotulopex]

Looking at your photos it looks as if Pin37 of the LCD R/W is connected via a blue/green wire to pin 13 of the PIC RB7. There also seems to be an additional brown wire flying off somewhere from this pin. Where does the other end of that connect to ?

It is the DATA wire (brown) coming from ICSP programmer (AN589). I've attached a "full view". Green LED on programmer is for power presence and yellow one (between both black relays) is for connection/disconnection of MCLR-DATA-CLOCK.

Wires:
black = GND (Vss)
red = +5V (Vdd)
yellow = MCLR
orange = Clock
brown = Data

One other point... I suggested putting LEDs on the PIC and observing it counting up to ensure that the count operated correctly. You said that you tested the pins with a logic probe, presumabley one pin at a time just to observe the two different states.

You're right. The LED you are talking about is there and as you suggest, I use it as an optical check. Do you mean I should connect more LEDs just to make sure it works fine?

Do you have access to a "normal" HD44780 display of any size just to test that your PIC is correctly configured. From what I have seen so far there shouldt be any real problems getting this display to work as it is 44780 compatible. If you try with a normal display and it still doesnt work then something isnt right with the PIC. Once you have that working it should just be a matter of swapping the displays.

Yes. As mentionned earlier, I made this check too and with my other displays (have lots of them), no problem!!

[keithdoxey]

It is the DATA wire (brown) coming from ICSP programmer (AN589).

Wires:
black = GND (Vss)
red = +5V (Vdd)
yellow = MCLR
orange = Clock
brown = Data

Ok. might be worth trying with R/W just connected to 0V.

You're right. The LED you are talking about is there and as you suggest, I use it as an optical check. Do you mean I should connect more LEDs just to make sure it works fine?

Yes. Put 8 leds on there and observe the count eg

OFF OFF OFF OFF OFF OFF OFF OFF (0)
OFF OFF OFF OFF OFF OFF OFF ON  (1)
OFF OFF OFF OFF OFF OFF ON  OFF (2)
OFF OFF OFF OFF OFF OFF ON  ON  (3)
OFF OFF OFF OFF OFF ON  OFF OFF (4)
OFF OFF OFF OFF OFF ON  OFF ON (5)
......
ON  ON  ON  ON  ON  ON  OFF OFF (252)
ON  ON  ON  ON  ON  ON  OFF ON (253)
ON  ON  ON  ON  ON  ON  ON  OFF (254)
ON  ON  ON  ON  ON  ON  ON  ON (255)

If the sequence doesnt work then the port isnt being correctly set

Yes. As mentionned earlier, I made this check too and with my other displays (have lots of them), no problem!!

Sorry, missed that.

Good luck !!!!

Keith

[flotulopex]

I must wait unil tomorrow morning: missing a few LEDs...

[Darrel Taylor]

flotul,

I've been looking at the pictures, and it appears that the data bus is reversed.

There's 4 wires (2 geen, 2 white) on lcd pins 28-31. They are connected like this.

<pre> LCD PIC <br> 31 (D4) 9 (B3)<br> 30 (D5) 8 (B2)<br> 29 (D6) 7 (B1)<br> 28 (D7) 6 (B0)<br></pre>Should be the other way around.
<br>

[keithdoxey]

flotul,

I've been looking at the pictures, and it appears that the data bus is reversed.

There's 4 wires (2 geen, 2 white) on lcd pins 28-31. They are connected like this.

<pre> LCD PIC <br> 31 (D4) 9 (B3)<br> 30 (D5) 8 (B2)<br> 29 (D6) 7 (B1)<br> 28 (D7) 6 (B0)<br></pre>Should be the other way around.
<br>

You have better eyes than me. I cant tell from the photos.

Would be a lot easier with 4 different colours though, or even GGWW instead of GWWG because at least you could tell it was reversed