Hello all. I am currently working on trying to connect an Arduino Due to my NHD-2.4-240320AF-CSXP display. I am using the Adafruits ST7789 library along with the gfx library. The display I am using uses 3/4 wire SPI communication (SDA), SDO, CS, SCLK. While the Adafruit library says it is 3 wire but needs me to use MOSI, SCLK, DC, CS, and RESET. I understand That SDO is MOSI however, I don't have an SCLK pin. On the data sheet of the display it says I can use the DC line as the SCLK line. However as you can see, how can I use the DC line as SCLK if the library wants me to define it. Do you know if I can just ignore this or is there a specific work around I can use? Cheers!
How can we see?
You have posted no links, no code, no schematics. There is nothing for us to see.
Perhaps you could read the forum guide in the sticky post at the top of most sections of the forum.
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Connect the red wire to the black wire and grab a right-hand smoke shifter. However, for a more accurate and helpful answer, follow @PaulRB's suggestion.
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Sorry about that. Here is the Breakout board diagram
Here is the pin out from NHD
And here is the initilization code from Adafruit
#include <Adafruit_GFX.h> // Core graphics library
#include <Adafruit_ST7735.h> // Hardware-specific library for ST7735
#include <Adafruit_ST7789.h> // Hardware-specific library for ST7789
#include <SPI.h>
#if defined(ARDUINO_FEATHER_ESP32) // Feather Huzzah32
#define TFT_CS 14
#define TFT_RST 15
#define TFT_DC 32
#elif defined(ESP8266)
#define TFT_CS 4
#define TFT_RST 16
#define TFT_DC 5
#else
// For the breakout board, you can use any 2 or 3 pins.
// These pins will also work for the 1.8" TFT shield.
#define TFT_CS 10
#define TFT_RST 9 // Or set to -1 and connect to Arduino RESET pin
#define TFT_DC 8
#endif
// OPTION 1 (recommended) is to use the HARDWARE SPI pins, which are unique
// to each board and not reassignable. For Arduino Uno: MOSI = pin 11 and
// SCLK = pin 13. This is the fastest mode of operation and is required if
// using the breakout board's microSD card.
// For 1.44" and 1.8" TFT with ST7735 use:
//Adafruit_ST7735 tft = Adafruit_ST7735(TFT_CS, TFT_DC, TFT_RST);
// For 1.14", 1.3", 1.54", 1.69", and 2.0" TFT with ST7789:
Adafruit_ST7789 tft = Adafruit_ST7789(TFT_CS, TFT_DC, TFT_RST);
// OPTION 2 lets you interface the display using ANY TWO or THREE PINS,
// tradeoff being that performance is not as fast as hardware SPI above.
#define TFT_MOSI 11 // Data out
#define TFT_SCLK 13 // Clock out
// For ST7735-based displays, we will use this call
//Adafruit_ST7735 tft = Adafruit_ST7735(TFT_CS, TFT_DC, TFT_MOSI, TFT_SCLK, TFT_RST);
// OR for the ST7789-based displays, we will use this call
Adafruit_ST7789 tft = Adafruit_ST7789(TFT_CS, TFT_DC, TFT_MOSI, TFT_SCLK, TFT_RST);
Thank you.
lol
Thanks for the new information, I now understand your confusion, and I share it!
Maybe you could post a link to that, and mention what page you saw that advice on.
Heres the displays data sheet.https://newhavendisplay.com/content/specs/NHD-2.4-240320AF-CSXP.pdf
just tested a Waveshare ST7789 display on an Arduino DUE
ran File>Examples>Adafruit_ST7735_and_ST7789_Library>graphicstest_st7789 OK with following connections
// Adruino Due
// DIN to ICSP header MOSI
// CLK to ICSP header SCK
#define TFT_CS 10
#define TFT_RST 9 // Or set to -1 and connect to Arduino RESET pin
#define TFT_DC 8
Thank you for your reply. My problem is that I do not have a dedicated CLK pin on my display. I have to run the DC line as my CLK pin. I am wondering if there is a way I can edit the adafruit library code to not need the DC line so I can setup my display.
the documentation is very vague and all the example code appears to be for parallel interfacing to the display
maybe worth getting on to Newhaven help to ask about SPI interfacing
Here is a Wokwi simulation using an ILI9341. I don't think you have to edit the library or change the pins name to use it with your display. Just pretend DCX is labeled SCK (SPI clock)...
using the sclk pin and placing it where the dc pin should be didnt seem to work on my simulation. I cant use both the dc and sclk pin since my nhd doesnt have a dedicated sclk pin on the board. i have sdo sda dc cs and res.
Did you ever have a sketch working with this display?
In case you didn't, here is a code (for the Arduino Mega) I got from newhavendisplay support and adapted for the Nano: (BTW, which board are you running the code on?)
/*****************************************************
This code was written for the Arduino Mega and allows to choose between 8080 parallel interface and 3-wire SPI Interface.
Newhaven Display invests time and resources providing this open source code,
Please support Newhaven Display by purchasing products from Newhaven Display!
Copyright (c) 2023, Newhaven Display International
This code is provided as an example only and without any warranty by Newhaven Display.
Newhaven Display accepts no responsibility for any issues resulting from its use.
The developer of the final application incorporating any parts of this
sample code is responsible for ensuring its safe and correct operation
and for any consequences resulting from its use.
See the GNU General Public License for more details.
/*----------------------------------------------------------------------------
Arduino Mega TFT Display |
------------------------------------------------------------------------------
GND 1 GND - Ground |
NC 2-5 - No Connect |
NC 6 SDO - Serial data out |
3.3V 7 VDD - Supply Voltage for LCD (3.3v) |
3.3V 8 VDDI - Supply Voltage for Logic (3.3) |
24 9 SDA - Serial data in |
23 10 CSX - Active LOW Chip Select signal(can tie to GND) |
25 11 DCX - D/C Data =1 , Command =0 |
29 12 WRX - Active LOW Write signal |
28 13 RDX - Active LOW Read signal |
NC 14-21 - No Connect |
49 22 DB0 |
48 23 DB1 |
47 24 DB2 |
46 25 DB3 |
45 26 DB4 |
44 27 DB5 |
43 28 DB6 |
42 29 DB7 |
10 30 RESX |
26 31 IM0 = 1 HIGH for 8080-II ; IM0 = 1 HIGH 3-wire SPI |
27 32 IM2 = 0 LOW for 8080-II ; IM2 = 1 HIGH 3-wire SPI |
GND 33 GND - Ground |
GND 34 LED-K1 Backlight Cathode |
GND 35 LED-K2 Backlight Cathode |
GND 36 LED-K3 Backlight Cathode |
GND 37 LED-K4 Backlight Cathode |
3.1V 38 LED-A Backlight Anode(160mA @ 3.1V) |
GND 39 Ground |
NC 40 TE |
----------------------------------------------------------------------------*/
#define RESX 8 /*RESX signal connected to Arduino digital pin 8*/
#define CSX 9 /*CSX signal connected to Arduino digital pin 9*/
#define SDA 11 /*SDA signal connected to Arduino digital pin 11*/
#define DCX 13 /*DCX signal connected to Arduino digital pin 13*/ //SCL pin when SPI
void Command_out(unsigned char c) //Function used for sending commands to TFT
{
PORTB &= ~(1 << PORTB3); //Set SDA LOW for D/C Bit
PORTB |= (1 << PORTB5); //Set SCL LOW
PORTB &= ~(1 << PORTB5); //Set SCL HIGH
PORTB |= (1 << PORTB5); //Set SCL LOW
for (int i = 0; i < 8; i++) {
if ((c & 0x80) == 0x80)
PORTB |= (1 << PORTB3); //Set SDA HIGH
else
PORTB &= ~(1 << PORTB3); //Set SDA LOW
c = (c << 1); //Shift byte
PORTB |= (1 << PORTB5); //Set SCL LOW
PORTB &= ~(1 << PORTB5); //Set SCL HIGH
PORTB |= (1 << PORTB5); //Set SCL LOW
}
}
void data_out(unsigned char d) { //Function used for sending data to TFT
PORTB |= (1 << PORTB3); //Set SDA HIGH for D/C Bit
PORTB |= (1 << PORTB5); //Set SCL LOW
PORTB &= ~(1 << PORTB5); //Set SCL HIGH
PORTB |= (1 << PORTB5); //Set SCL LOW
for (int i = 0; i < 8; i++) {
if ((d & 0x80) == 0x80)
PORTB |= (1 << PORTB3); //Set SDA HIGH
else
PORTB &= ~(1 << PORTB3); //Set SDA LOW
d = (d << 1);
PORTB |= (1 << PORTB5); //Set SCL LOW
PORTB &= ~(1 << PORTB5); //Set SCL HIGH
PORTB |= (1 << PORTB5); //Set SCL LOW
}
}
void Set_XY_Address() {
Command_out(0x2A); /*Set x column */
data_out(0x00);
data_out(0x00);
data_out(0x00);
data_out(0xEF);
Command_out(0x2B); /*Set y row */
data_out(0x00);
data_out(0x00);
data_out(0x01);
data_out(0x3F);
Command_out(0x2C); /*command to begin writing to frame memory */
}
void disp() {
Set_XY_Address();
unsigned int i;
for ( i = 0; i < 38400; i++)
{
data_out(0x00);
data_out(0x1f); //Fills screen with Red pixels
data_out(0x00);
data_out(0x1f);
}
delay(2000);
Set_XY_Address();
for ( i = 0; i < 38400; i++)
{
data_out(0x07); //Fills screen with Green pixels
data_out(0xe0);
data_out(0x07);
data_out(0xe0);
}
delay(2000);
Set_XY_Address();
for ( i = 0; i < 38400; i++)
{
data_out(0xf8); //Fills screen with Blue pixels
data_out(0x00);
data_out(0xf8);
data_out(0x00);
}
delay(2000);
}
void Ports_SPI() {
DDRB = 0xFF; //Enable All pins as output on PortB
PORTB = 0x00; //Clears PortB
digitalWrite(CSX, LOW);
}
void TFT_init() {
digitalWrite(RESX, LOW);
delay(250);
digitalWrite(RESX, HIGH);
delay(250);
Command_out(0x28); //display off
Command_out(0x11); //exit SLEEP mode
delay(100);
Command_out(0x36); //MADCTL: memory data access control
data_out(0x88);
Command_out(0x3A); //COLMOD: Interface Pixel format *** 65K-colors in 16bit/pixel (5-6-5) format when using 16-bit interface to allow 1-byte per pixel
data_out(0x55);
Command_out(0xB2); //PORCTRK: Porch setting
data_out(0x0C);
data_out(0x0C);
data_out(0x00);
data_out(0x33);
data_out(0x33);
Command_out(0xB7); //GCTRL: Gate Control
data_out(0x35);
Command_out(0xBB); //VCOMS: VCOM setting
data_out(0x2B);
Command_out(0xC0); //LCMCTRL: LCM Control
data_out(0x2C);
Command_out(0xC2); //VDVVRHEN: VDV and VRH Command Enable
data_out(0x01);
data_out(0xFF);
Command_out(0xC3); //VRHS: VRH Set
data_out(0x11);
Command_out(0xC4); //VDVS: VDV Set
data_out(0x20);
Command_out(0xC6); //FRCTRL2: Frame Rate control in normal mode
data_out(0x0F);
Command_out(0xD0); //PWCTRL1: Power Control 1
data_out(0xA4);
data_out(0xA1);
Command_out(0xE0); //PVGAMCTRL: Positive Voltage Gamma control
data_out(0xD0);
data_out(0x00);
data_out(0x05);
data_out(0x0E);
data_out(0x15);
data_out(0x0D);
data_out(0x37);
data_out(0x43);
data_out(0x47);
data_out(0x09);
data_out(0x15);
data_out(0x12);
data_out(0x16);
data_out(0x19);
Command_out(0xE1); //NVGAMCTRL: Negative Voltage Gamma control
data_out(0xD0);
data_out(0x00);
data_out(0x05);
data_out(0x0D);
data_out(0x0C);
data_out(0x06);
data_out(0x2D);
data_out(0x44);
data_out(0x40);
data_out(0x0E);
data_out(0x1C);
data_out(0x18);
data_out(0x16);
data_out(0x19);
Command_out(0x2A); //X address set
data_out(0x00);
data_out(0x00);
data_out(0x00);
data_out(0xEF);
Command_out(0x2B); //Y address set
data_out(0x00);
data_out(0x00);
data_out(0x01);
data_out(0x3F);
delay(10);
Command_out(0x21); //Color inversion for ips
Command_out(0x29); //display ON
delay(10);
}
void setup() {
Ports_SPI(); //Ports setup for SPI Interface
TFT_init(); //TFT initialization
}
void loop() {
disp(); //Outputs RGB colors loop
}
Does it work? Or maybe it doesn't suit your needs...
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