NHD-0420DZW-AY5 and Arduino

Hi
I have spent several hours, even days, trying to communicate properly and robustly with the NHD-0420DZW-AY5 from an Arduino Nano but in vain. Neither the standard Arduino way, nor third-party examples, nor trying from scratch myself and nor using this: https://newhavendisplay.com/content/app_notes/4_bit_character.txt  seems to work, when converted as below (16 vs 20 char can hardly be the issue):

#define lcdRS      3   // D/I is P3.0
#define lcdRW     13   // WR is P3.7 ***GND***
#define lcdEnable  4   // E is P3.4  active LOW
#define lcdData4   9
#define lcdData5  10
#define lcdData6  11
#define lcdData7  12

char msg0[] = "Newhaven Display";
char msg1[] = "4-bit interface ";

void nybble()
{
    digitalWrite(lcdEnable, LOW);  // Reset P3.4  'E
    delay(1);                      // Waitms 1    'enable pulse width  >= 300ns
    digitalWrite(lcdEnable, HIGH); // Set P3.4    'E
}

void writeCom(byte val)
{
    digitalWrite(lcdData4, (val >> 4) & 1); // P1 = Com 'move data to Port 1
    digitalWrite(lcdData5, (val >> 5) & 1);
    digitalWrite(lcdData6, (val >> 6) & 1);
    digitalWrite(lcdData7, (val >> 7) & 1);
    digitalWrite(lcdRS, LOW);     // Reset P3.0 'RS = Instruction register
    nybble(); // Call Nybble 'write high 4 bits

    digitalWrite(lcdData4, val & 1); // Rotate Com , Left , 4  'rotate; P1 = Com 'move data to Port 1
    digitalWrite(lcdData5, (val >> 1) & 1);
    digitalWrite(lcdData6, (val >> 2) & 1);
    digitalWrite(lcdData7, (val >> 3) & 1);
    nybble(); // Call Nybble 'write low 4 bits
}

void writeData(byte val)
{
    digitalWrite(lcdData4, (val >> 4) & 1); // P1 = A
    digitalWrite(lcdData5, (val >> 5) & 1);
    digitalWrite(lcdData6, (val >> 6) & 1);
    digitalWrite(lcdData7, (val >> 7) & 1);
    digitalWrite(lcdRS, HIGH);     // Set P3.0  'RS = Data register
    nybble(); // Call Nybble

    digitalWrite(lcdData4, val & 1); // Rotate A , Left , 4, P1 = A
    digitalWrite(lcdData5, (val >> 1) & 1);
    digitalWrite(lcdData6, (val >> 2) & 1);
    digitalWrite(lcdData7, (val >> 3) & 1);
    nybble(); // Call Nybble
}

void setup()
{
    // Pin setup
    pinMode(lcdRS, OUTPUT);
    pinMode(lcdRW, OUTPUT);
    pinMode(lcdEnable, OUTPUT);
    pinMode(lcdData4, OUTPUT);
    pinMode(lcdData5, OUTPUT);
    pinMode(lcdData6, OUTPUT);
    pinMode(lcdData7, OUTPUT);

    // Communicate with LCD
    digitalWrite(lcdRS, HIGH);     // Set P3
    digitalWrite(lcdRW, LOW);      // Somewhat a contradiction to set P3!!!!!!!!!!
    digitalWrite(lcdEnable, HIGH);
    digitalWrite(lcdRS, LOW);     // Reset P3.0
    delay(100);                   // Waitms 100

    digitalWrite(lcdData4, HIGH); // A = &H30; P1 = A
    digitalWrite(lcdData5, HIGH);
    digitalWrite(lcdData6, LOW);
    digitalWrite(lcdData7, LOW);

    nybble();                     // Call Nybble 'wake up
    delay(100);                   // Waitms 100
    nybble();                     // Call Nybble 'wake up
    delay(10);                    // Waitms 10
    nybble();                     // Call Nybble 'wake up
    delay(10);                    // Waitms 10

    digitalWrite(lcdData4, LOW);  // A = &H20 ' 4-bit interface; P1 = A
    digitalWrite(lcdData5, HIGH);
    digitalWrite(lcdData6, LOW);
    digitalWrite(lcdData7, LOW);
    nybble();
   
    writeCom(0x28);  // Com = &H28 '4-bit 2 lines; P1 = A; Call WriteCom
    writeCom(0x10);  // Com = &H10 'cursor shift; Call WriteCom
    writeCom(0x0F);  // Com = &H0F 'display on; Call WriteCom
    writeCom(0x06);  // Com = &H06 'entry mode; Call WriteCom   

    writeCom(0x01);  // Com = &H01 'home; Call WriteCom   
    for (byte i = 0; i < 16; i++)  // Restore Dta1; For Count = 1 To 16; Next Count
    {
        writeData(msg0[i]);        // Read A; Call Writedata
    }

    writeCom(0xC0);  // Com = &HC0 '2nd line
    for (byte i = 0; i < 16; i++)  // Restore Dta1; For Count = 1 To 16; Next Count
    {
        writeData(msg1[i]);        // Read A; Call Writedata
    }
    delay(5);
}

void loop()
{
}