NT7108

I am testing the LCD based on chip NT7108.

Using Libraries OpenGLCD and u8glib, But LCD is not working
LCD is powered by 5V and backlighted with 3V.

Would you like to help me please.

Datasheet is attached

RG12864B-BIW-V.pdf (1.42 MB)

Can you post the output of the diagnostic sketch and photos of your setup so we can take a look a soldering and wiring?

--- bill

bperrybap:
Can you post the output of the diagnostic sketch and photos of your setup so we can take a look a soldering and wiring?

— bill

Serial initialized

Reported Arduino Revision: 1.8.5
F_CPU: 16000000

Lib Configuration: openGLCD ver: 1.0rc3 build: v1.0rc3
Panel Configuration:ks0108-128x64
Pin Configuration:ks0108-Uno

GLCD:ks0108 DisplayWidth:128 DisplayHeight:64
Chips:2 ChipWidth:64 ChipHeight:64
CSEL1:A0(PORTC0) CSEL2:A1(PORTC1)
RES:A5(PORTC5) RW:A2(PORTC2) DI:A3(PORTC3) EN:A4(PORTC4)
D0:8(PORTB0) D1:9(PORTB1) D2:10(PORTB2) D3:11(PORTB3)
D4:4(PORTD4) D5:5(PORTD5) D6:6(PORTD6) D7:7(PORTD7)
Delays: tDDR:320 tAS:140 tDSW:200 tWH:450 tWL:450
ChipSelects:
CHIP0:(A0,0x1, A1,0x0)
CHIP1:(A0,0x0, A1,0x1)
Data mode:
d0-d3:nibble mode-Non-Atomic
d4-d7:nibble mode-Non-Atomic
Backlight:

Diag Loop: 1
Initializing openGLCD

There should be more diagnostic output.
Is that all that printed?

bperrybap:
There should be more diagnostic output.
Is that all that printed?

Thats all...it is at this state from my post with diag ouput without addinitional printed lines.

I'll have to go look at the code but I don't think that the diagnostic can hang without printing more output.

Can you post some photos so we can look at your soldering and wiring to verify that it looks ok and that it matches the pins configured?

--- bill

I Atached screen with wiring description.

Again thx for helps.

Are you the same person that sent me emails about this?
If so, the diag output in the email had more information.

Can you do a mod to the diag sketch?
In the function SerialPrintP()
Add this line just after the while() loop

  Serial.flush(); // push out all buffered tx characters

So it looks like this:

void SerialPrintP(PGM_P str )
{
  char c;
  PGM_P p = str;

  while ((c = pgm_read_byte(p++)))
  {
    if(c == '\n')
      Serial.print('\r');
    Serial.print(c);   
  }
  Serial.flush(); // push out all buffered tx characters
}

— bill

bperrybap:
Are you the same person that sent me emails about this?
If so, the diag output in the email had more information.

Can you do a mod to the diag sketch?
In the function SerialPrintP()
Add this line just after the while() loop

  Serial.flush(); // push out all buffered tx characters

So it looks like this:

void SerialPrintP(PGM_P str )

{
  char c;
  PGM_P p = str;

while ((c = pgm_read_byte(p++)))
  {
    if(c == '\n')
      Serial.print('\r');
    Serial.print(c); 
  }
  Serial.flush(); // push out all buffered tx characters
}




--- bill
  • Yes i am same person.

I did the modification but it does not helped.

But i commented lines in the loop function:
//#if ARDUINO >= 100
Serial.flush(); // push out all buffered tx characters
//#endif
// status = GLCD.Init(); // initialise the library, non inverted writes pixels onto a clear screen

And now i have additional line in terminal:
Displaying Library version Screen

namefree:
But i commented lines in the loop function:
//#if ARDUINO >= 100
Serial.flush(); // push out all buffered tx characters
//#endif
// status = GLCD.Init(); // initialise the library, non inverted writes pixels onto a clear screen

And no i have additional line in terminal:
Displaying Library version Screen

I don't understand what you are doing.
Why have you commented out code in loop()?

And I don't understand what you have said below the commented code.

--- bill

namefree:
I Atached screen with wiring description.

Again thx for helps.

I can’t really tell how you have wired up the glcd.
The photo is also too close as I can’t see how you have wired up your contrast circuit (the potentiometer)

— bill

bperrybap:
I can't really tell how you have wired up the glcd.
The photo is also too close as I can't see how you have wired up your contrast circuit (the potentiometer)

--- bill

I just tried to comment Arduino version checking...but it is reverted back.

I am currently working on wirign diagram i will post it here in few minutes.

namefree:
I just tried to comment Arduino version checking...but it is reverted back.

But you also had commented out the call do GLCD.Init() which initializes the library & hardware.

I am currently working on wirign diagram i will post it here in few minutes.

Have you wired up the potentiometer to the glcd?
It connects to the contrast input pin (Vo, pin 3), VCC, and VEE.

Without that, you will never see any pixels on the display.

Are you %100 sure that the datasheet you are using is for your exact display module?
There are many different pinouts for this type of display as there is no standard or consistent way to connect
the signals to the 20 pins on the module.

--- bill

SOLVED :

I Loaded contrast with +5V. But it should beloaded from VEE PIN.

Many Thanks to bperrybap - he really hit the problem.

I hope my schematic will help to the other users

So it is working now?
Is the diag test passing?

bperrybap:
So it is working now?
Is the diag test passing?

Yes, thank you very much for you coolest help. LCD was not correctly wired (missing negative voltage for contrast).

There must have been more than just the contrast wiring.
If the contrast wiring is incorrect then the display pixels will not light up or all the pixels will be on
but the diagnostic test would still pass.
You showed me two different issues.
One where the glcd initialization didn't work because of a RESET timeout.
And a 2nd one where the diag output stopped like the diagnostic sketch hung.
Neither of those can be caused by a simple contrast wiring problem.

-- bill

bperrybap:
There must have been more than just the contrast wiring.
If the contrast wiring is incorrect then the display pixels will not light up or all the pixels will be on
but the diagnostic test would still pass.
You showed me two different issues.
One where the glcd initialization didn't work because of a RESET timeout.
And a 2nd one where the diag output stopped like the diagnostic sketch hung.
Neither of those can be caused by a simple contrast wiring problem.

-- bill

When i connected contrast pins then it has been started working without any other modification.

But one small think x=0 is in the middle, so i swapped wires CS1 and CS2, after this is the x=0 exactly in left corner.