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Messages - Dave

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Character LCDs / Lesson learned
« on: March 04, 2015, 07:29:00 AM »
See prior post for issue. Bottom line, my code worked from the start, the problem was that the SCK pin on PIC processor on the display was not soldered!
Should have gone with my instinct and checked the display first. Getting old sks

Character LCDs / Need help please with NHD-0420D3Z-fl-GBW-V3
« on: March 02, 2015, 09:29:51 AM »
Has anyone used this display in the SPI mode with a Pic processor(pic18f2620)? If so any code to share?

Iíve tried using the SPI peripheral and straight bit bang, still canít get the display to work other than in test mode.
I have R2 shorted with a zero ohm 0603 resistor,I have set the CKP to 1 and the CKE to 1, the clock is set to 62.5kHz. I also tried different modes (grasping at straws now). Looking at the signals with a scope and all seems well, seeing as there are now timing diagrams to check against.
As I understand it when the display powers up, it powers up in the on mode, therefore all I should have to do is send 0x13(code for the #1), and the display should display a ď1Ē, I got nothing, I even tried turning on the display, setting the curser to home first.

void initialize_spi()
    LATBbits.LATB4 = 1;/*disable lcd*/
     SSPCON1 = 0;
    SSPCON1bits.SSPEN = 0;/*Synchronous Serial Port Enable bit  DISABLED*/
    SSPCON1bits.SSPM = 2;/*SPI Master mode, clock = FOSC/64*/
    SSPCON1bits.CKP = 1;/*Clock Polarity Select bit*/
    SSPSTATbits.CKE = 1;/*SPI Clock Edge Select bit (SPI mode only)*/


void test()
    LATBbits.LATB4 = 0;/*Set LCD select low*/
    PIR1bits.SSPIF = 0;/*clear Synchronous Serial Port Interrupt Flag bit*/
    SSPBUF = 0x13;
    while(!PIR1bits.SSPIF);/*The transmission/reception is complete (must be cleared in software)*/
   LATBbits.LATB4 = 1;/*Set LCD select high*/

Second test function bit bang
void lcd_test(unsigned char DATA)
    unsigned int n,x;
    unsigned char data;
    data = DATA;
    LCD_SEL = 0;/*Set LCD select low*/
     for(n = 0; n<8;n++)
         if((data & 0x80) == 0x80) SDO = 1; /*LATCbits.LATC5 = 1;*/
         else SDO = 0; /*LATCbits.LATC5 = 0;*/
         data = data << 1;
         SCK = 0;
         SCK = 1;
     SCK = 1;/*set clock high*/
     LCD_SEL = 1;/*Set LCD select high*/
I can see no reason why this isnít working, other than the SPI front end on the display is Tango Uniform.

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