LCDOUT custom commands - how to?

Hello,

I just bought a LCD from ELECTRONIC ASSEMBLY http://www.lcd-module.de/deu/pdf/doma/dog-m.pdf. It is a ST7036 (HD44780 compatible) controlled display.

After I made all required connexions, it doesn't work but I think I need to initialise the display since some settings like "Display ON/OFF" and "Contrast" are set by software (no cabling).

I've got the initialisation codes in this table (see attachment) but... I don't really know how to use them.

I declared all DEFINEs and wrote

Code:

---

LCDOUT $FE, $0F

---

to switch the display on? Nothing happens - must be wrong.

The "$FE" must be wrong. I found also the documentation about the controller that pilots this display here http://www.lcd-module.de/eng/pdf/zubehoer/st7036.pdf.

It's surely not complicated, nevertheless I'm a little lost...

Nope, the first LCDOUT should take care of the initialisation. For safety sake use a 500mSec-1Sec at the top of your code before the first LCDOUT.

LCDOUT $FE,1 just clear the display.

Be sure you don't use your LCD on analog i/o AND/OR open drain type without using the right method (pull-up, set all I/Os to digital)

As usual, your WHOLE code and PIC# will help.

I'm still not sure how to connect the datalines from the display to the PIC (is it DB0 = D7 and so on or is it DB0 = D4 and so on).

Here is my code:

Code:

---

'PIC 16F88

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


DEFINE LCD_DREG PORTA      'LCD data port
DEFINE LCD_DBIT 4          'LCD data starting bit 0 or 4
DEFINE LCD_RSREG PORTA      'LCD register select port
DEFINE LCD_RSBIT 4          'LCD register select bit
DEFINE LCD_EREG PORTA      'LCD enable port
DEFINE LCD_EBIT 6          'LCD enable bit
DEFINE LCD_RWREG PORTA      '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


START:
    Lcdout $FE, 1          'Clear screen


MAIN:
    pause 1000
    lcdout $FE, 2,  "This is line one"
    lcdout $FE, $C0, "This is line two"
    goto MAIN

end

---

This...

'28 DB0 - PORTA.0
'29 DB1 - PORTA.1
'30 DB2 - PORTA.2
'31 DB3 - PORTA.3

is not compatible with this...

DEFINE LCD_DREG PORTA 'LCD data port
DEFINE LCD_DBIT 4 'LCD data starting bit 0 or 4

...and double-check with the Datasheet that you've disabled all Analogue Functions on PortA.

The display's datasheet makes me connect the lines D4 to DB3, D5 to DB2, D6 to DB1 and D7 to DB0 (see attachment "DB-Lines_connections.jpg"). This is why I thought the starting bit would be the fourth.

I changed:

Code:

---

DEFINE LCD_DREG PORTA      'LCD data port
DEFINE LCD_DBIT 0          'LCD data starting bit 0 or 4

---

and added:

Code:

---

ADCON0.0  = 0              'Disable Converter Module

---

I went through the PIC's datasheet and couldn't find other settings that could affect the A ports. Still, the display looks just dead.

I have two of them and react the same. I changed for my second 16F88 and the result is same too.

Normally for a 4 bit bus

DB0-DB3 = D4-D7

Also if you are using a 16F88 check the ANSEL register

ANSEL is set to have all analog ports disabled.

As you suggested, I connected DB0 to D4 and so on...

Still nothing happens.

I'm just suprised that the display don't even flickers a little. It looks just like dead. Two displays doing the same makes me think I'm doing something wrong.

Is is right to say that to make it work the Enable bit must be high? If yes, I could at least mesure it with my logic probe or oscillo....

What can I "electrically" check else to minimise the cabling error risk?

Is there (or should there be) a contrast control that needs adjusting ?

i'm not sure if PBP handle the R/W line itself.

How about LOW PORTA.7

AND maybe i'm blind.. i don't see any config fuses?

On some LCD, you need to tie the unused DB lines to GND, in your case they should be tied to 5V.

AND what about the CSB line?
<img SRC="http://www.picbasic.co.uk/forum/attachment.php?attachmentid=1215&d=1164381937">

Mister_e don't worry, your eyes are absolutely fine ;-)

I'm using ICProg to program the µC and the fuses are set in there since I can't pass this kind of settings from PBP.

The actual settings are:
WDT:ON
PWRT:ON
MCLR:ON
BODEN:ON
LVP:OFF
CPD:OFF
DEBUGGER:OFF
CCPMX:ON

I've connected the display as it is described on the schematic so the DB line are all connected to Vdd and the CSB (I don't know what this is for) is connected to Vss.

I just tried the PORTA.7 = 0 option.... still nothing.

Keith, the contrast control is software set. I agree, this could be the problem and this is also why I need to understand how I have to adress (exact command syntax) the display.

The LCD CONTRAST setting could be the problem.

I've attached the initialisation codes for this display (unfortunately, it's an 8 bit example - is it important?). Is it possible that the LCDOUT $FE command doesn't fit with this display's controller (ST7036)?

Quote:

---

Originally Posted by flotulopex

Mister_e don't worry, your eyes are absolutely fine ;-)

I'm using ICProg to program the µC and the fuses are set in there since I can't pass this kind of settings from PBP.

---

Hi flotulopex, I use IC PROG and I pass the config fuse data to it from code always. Which assembler are you using PBP or MPASM? Also what osc speed?

Code:

---

for MPASM try
@MyConfig = _HS_OSC & _WDT_ON & _PWRTE_ON & _MCLRE_ON & _LVP_OFF
@MyConfig = MyConfig  & _CP_OFF & _BODEN_ON & _DATA_CP_OFF
@ __config  MyConfig

for PBP try
@ DEVICE pic16F88, HS_OSC
' Set Oscillator Fuse in Programmer to high speed make XT for low speed
@ DEVICE pic16F88, WDT_ON
' Watchdog Timer

@ DEVICE pic16F88, PWRT_ON
' Power-On Timer

@ DEVICE pic16F88, MCLR_ON
' Master Clear Options (Internal)

@ DEVICE pic16F88, BOD_OFF
' Brown-Out Detect

@ DEVICE pic16F88, LVP_OFF
' Low-Voltage Programming

@ DEVICE pic16F88, CPD_OFF
' Data Memory Code Protect
' Set to CPD_OFF for Development Copy
' Set to CPD_ON for Release Copy

@ DEVICE pic16F88, PROTECT_OFF

---

Also make sure to define your oscillator if you do not use default 4 mhz
JS

There are basically two things that could be stopping you display from working.

1. a problem with the PIC

2. a problem with the display.


To test 1....

I would assign an entire 8 bit port for the LCD eg PortB (just for test purposes) and connect LEDs to each bit. Also put LEDs on the pins of another port that you will use for the control lines.

Have a count run from 0-255 and output that to port B and observe that the LEDs count up correctly.

Likewise output all possible combinations on the pins you use for the control lines just to ensure that all your output pins are correctly configured and can successfully light the LEDs.


to test 2......

Once you know that you PIC is capable of driving all the required lines, connect up the LCD display in 8 bit mode and then try all the commands to get it working. Once you have it working it should be simple to change to 4 bit mode.

As far as I can see the only difference between 4 and 8 bit mode is in the initialisation which tells the LCD how it is connected. All subsequent commands should be the same, the only difference being that instead of sending a byte you have to send two nibbles instead which obviously takes twice as long.

I have had a further thought about something that caught me out a few weeks ago when changing to a different display. I didnt have the R/W line connected to the PIC, but I also didnt have it tied to anything either. The origianl display must have had some form of internal pullup/pulldown resistor as it didnt mind about the floating pin but the new display would not do anything until correctly terminated.

The second datasheet you mentioned for the actual controller chip has full examples of initialising in 8 and 4 bit mode so all the actual values you need are listed there. Ignore the fact that it is written in 8051 assembler just use the values in your PBP code. Being 44780 compatable means that it should work fine with LCDout so my bet is a misconfiguration of the PIC or a wiring fault unless you are really unlucky and have killed a piece of hardware.

Wow Joe S!!

Yes it works; I'm very surprised indeed. I was told it was not possible with ICProg.

I'm using PBP. Where did you find the correct syntax to use for every fuses?



Keith,

You're right. Let's go on with method. I'm starting to check as you suggest. Will come back when done.

Hi Keithdoxey,

I tested the PIC with my logic probe and hope doing so is fine (please let me know if it is not a good practice - I'm not an electronician).

My PIC looks okay so far.

Going now to the second step: check the LCD.

Come back later.

Quote:

---

Originally Posted by flotulopex

I'm using PBP. Where did you find the correct syntax to use for every fuses?

---

If you're using PM, open m16f88.inc file in c:\pbp\inc folder, they're located at the top.

If you're using MPASM, open p16f88.inc file in C:\Program Files\Microchip\MPASM Suite folder. They're located at the bottom.

There's a huge thread Here about that.

Thanks Mister_e,

Fuse config is now clear to me ;-)

Back to my display, I did what keithdoxley suggested but still it's not working.

Finally, I connected my usual display on the PIC with an 8 bit data-bus. It works fine so, for sure, the PIC is not the problem.

I have contacted ELECTRONIC ASSEMBLY and asked for more informations. I still can't believe I would have broken both displays...

For normal use, the display must be set in Read or Write (R/W)?

One last thing about the contrast control: would be the syntax to change the contrast's setting "LCDOUT $FE, $74"? According to the table (Initialise_LCD.bmp) in post #10, it should but how to change the amount of contrast???

Quote:

---

Thanks Mister_e,

Fuse config is now clear to me ;-)

---

You're welcome, It's always handy to have theses in your code.

Quote:

---

One last thing: for normal use, the display must be set in Read or Write (R/W)?

---

Unless you want to read from your LCD (Wich i still don't understand why anyway) you should set the PIN to 0, low, gnd.

Yes, really handy. Thanks a lot again.

I would appreciate to find some more explanations on how to read (understand) and write to the display the configuration commands such as LCDOUT $FE, xxx.

Merci encore.

I've got an answer from ELECTRONIC ASSEMBLY (EA). They say this display is fully HD4470 compatible.

So, until the contrast (all the display in fact) is not initialised properly, nothing will happen on the display.

I've got this table extracted from the PDF file I inserted in my first post:
http://home.citycable.ch/flotulopex/...ialise_LCD.bmp

This example is for a 8 bits display. I would prefer to use it with 4 bits but if it is easier to start this way...

Can somebody tell me what syntax I have to use to modify the contrast settings?

Is it LCDOUT $FE, $74? I tried this already but nothing happened.

I don't understand how to use this table. Could somebody explain me please?

BTW, EA also sent me some assembly examples (see attachments); for those who understand this, it may help, maybe. Unfortunately, I don't know assembler...

Mister_e, see the picture? Thanks you, again ;-)

Take a look at http://www.lcd-module.de/eng/pdf/zubehoer/st7036.pdf

Pages 34-38 tell you exactly what each register contains and what each bit does.

Page 39 shows 8 bit initialisation

Page 41 shows 4 bit initialistaion but you dont need to go down to that lave. PBP should take care of that for you.

Just look for the commands that set the contrast. It look to be "$7x" where x is the setting 0-F for the 16 possible values.

I would follow Steves advice for leaving a long delay after the first initialistaion command then try something like this

Code:

---


contrast            var byte
contrastcommand var byte



For contrast = 0 to 15
  contrastcommand = $70 + contrast
  LCDout $FE, contrastcommand
  pause 10
  LCDout $FE,1, "contrast=", DEC2 contrast
  pause 1000
Next

---

That should send all possible values to the LCD for adjusting the contrast and if it works you will see on the display the values that give a visible display. Then pick the best one.

Cant really offer much more as I dont have that type of display.

Okay.

I'll go back to my breadboard and try.

Come back asap.

I did almost everything all of you suggested.

Still nothing works; the display is just not showing anything.

I even tried to reverse the bus order (sorry Melanie) since the guy from EA said this would be so (but I can't believe it - D0 on display should be connected to DB0 and so on, for sure).

Ii is now sunday 15:45 local time and I won't be able to have news before tomorrow morning.

So, let's wait a little...

Can you try...

Code:

---

' 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, $30
    Lcdout $FE, $30
    Lcdout $FE, $30
    Lcdout $FE, $20 ' official 4 bit mode
    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

---

there's still some more code efficient solutions so far..

Hey Steve.

I could be wrong, but I think it needs a fix.

The LCD will Power-up in 8-bit mode, but PBP will still be sending 4-bit.
So each nibble acts as a full command.
If you use $33 (twice), then it will get the "reset" 4 times, instead of $30,$00,$30,$00 ...

Then when it switches to 4-bit mode, it receives an extra nibble from the $20 which puts it out of sync with the rest of the data. By pulsing the E pin once it clocks in another $0 which is a "nothing" command and puts it back in sync.

Like this ...

Code:

---

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

 ; -- rest is the same --

---

Hi flotulopex,
Ms Melanie mentioned to make sure all analog stuff is off, I saw no mention of the comparators. That silly 16F88 uses them. One of the harder early 16f series to set up because it uses ansel, adcon and cmcon registers and people seem to miss one or the other.
CMCON=7
JS

Darrel, i think you're right. My previous work on a regular 44780 controller type so far but will send
3,0,3,0,3,0, and lastly 2,0... so 3 not really needed 0's... :(

I did something else, but i don't think it will be handy now.

NOW...

Code:

---

    @  bsf LCD_EREG, LCD_EBIT
    PAUSEUS 20
    @  bcf LCD_EREG, LCD_EBIT

---

yup, or

Code:

---

    @  bsf LCD_EREG, LCD_EBIT
    @  PAUSEUS?C LCD_DATAUS
    @  bcf LCD_EREG, LCD_EBIT

---

Joe S. The analog comparator are disable at POR on this one. But it's always nice to include the line too as safety sake.

It's so cruel: when I think all has been done, you All come with more suggestions and I'm in my office now and will have to wait until this evening to try all this out ;-)

Okay Joe, I'll try this one. You're right, some settings on this PIC can be tricky if we forget them.

Darrel, you're far ahead of what I'm able to understand. It sounds so clear for you. What shall I do, replace Mister_e's $30 by your $33?

Merci Steve, it will be easy to copy/paste and check quickly.

Come back to you later.

Thank you All.

Until I can try all what you suggest, I would like to understand how you Guys read and interpret the codes in the Initialisation Table I put in my post #19. It looks so obvious to you, unfortunately it is not to me...

As an example, I would like to know how you come to a LCDOUT $FE, $0C to switch On the display.

In the table the line sais Display ON/OFF, you see the bits RS(I don't even know what this one is for) and R/W, and then you have for each DB7...0 a value (0 or 1). Finally you've got this $0F value which appears to me as coming from nowhere.

I admit that the $FE is a standart value for sending datas to the display.

But, in this example, where comes the $0C from? I'm lost...

I'm missing this very basic stuff and bothering you with stupid questions so was this discussed in antoher thread already?

Quote:

---

Originally Posted by flotulopex

But, in this example, where comes the $0C from? I'm lost...

---

Hi flotulopex,
No question you do not know the answer to is stupid.
$0C - listed in PBASIC PRO MANUAL page 94. $0C = Cursor Off
JS

Hello Joe S.,

I read this document (PBP manual) almost any time I have a question but I sometimes don't understand the explanations.

As you mention, the actual $0C value listed in the manual switches the Cursor OFF; Mister_e sais that, according to the table, it switches the Display ON. There is a difference.

Mister_e must have interpreted the table; this is what I would like to be able to do too.

So, my question was more precisely to:
a) understand the definition table (in post #19);
b) learn how to use the informations on there.

I don't know how to express myself more clearly but if my question looks confusing, please tell me.

Quote:

---

Originally Posted by flotulopex

As you mention, the actual $0C value listed in the manual switches the Cursor OFF; Mister_e sais that, according to the table, it switches the Display ON. There is a difference.

Mister_e must have interpreted the table; this is what I would like to be able to do too.

So, my question was more precisely to:
a) understand the definition table (in post #19);
b) learn how to use the informations on there.

---

Look at the datasheet for the LCD controller, specifically Page 26.

"Display On/OFF"

The 8 bits for the register = 00001DCB

D= display 1=on 0=off
C=cursor 1=on 0=off
B=blink cursor 1=on 0=off

so "00001100"

Will give Display On Cursor and Blink off which is $0C

$0C is the command to turn the Cursor OFF but it also turns the dsipay on as well

$0E will turn the display on with a cursor

So, the code looks like this now:

Code:

---

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.

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.

Quote:

---

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

Quote:

---

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?

Quote:

---

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!!

Quote:

---

Originally Posted by flotulopex

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.

Quote:

---

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

Code:

---

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

Quote:

---

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

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

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>

Quote:

---

Originally Posted by 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.
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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 :)

Yeah, I was going Bug-Eyed :eek: too trying to follow them all.

PICT0003small.JPG in Post#34 helped.

Had to save it to disk so I could zoom in and out with an Image Preview.
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Quote:

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Originally Posted by Darrel Taylor

Yeah, I was going Bug-Eyed :eek: too trying to follow them all.

PICT0003small.JPG in Post#34 helped.

Had to save it to disk so I could zoom in and out with an Image Preview.
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I use Firefox and it's Zoom plugin, very helpful, Zoom in right in browser.
JS