4.0 vs 3.2 with Adafruit 1.3" 240.x240

[bsandipk]

Hello - I want to replace 3.2 with 4.0 Have the Adafruit 1.3" display (st7789_t3) link

https://smile.amazon.com/MakerFocus...ZQCQQ33DVT5&psc=1&refRID=WJQT43BX3ZQCQQ33DVT5

It was working on 3.2 but I am getting a blank screen on 4.0 - tried the graphicstest example sketch.

#define TFT_MISO 12
#define TFT_MOSI 11 //a12
#define TFT_SCK 13 //a13
#define TFT_DC 9
#define TFT_CS -1
#define TFT_RST 8
...
ST7789_t3 tft = ST7789_t3(TFT_CS, TFT_DC, TFT_MOSI, TFT_SCK, TFT_RST);
...
tft.init(240, 240, SPI_MODE2);

I am NOT using SD card etc - just teensy and the display.Any clues ?

Sandip

 

[KurtE]

Sorry you confused me with saying you have an Adafruit display, but then noticed you have set CS=-1, where as you actually have a MakerFocus

I have 2 of them which have worked with T4. So it should work. See the thread: https://forum.pjrc.com/threads/5701...-library)-support-for-displays-without-CS-pin

So I would double check the wiring and the like.

 

[el_supremo]

I've just got one of that type of display working today. I think part of your problem might be that you use ST7789_t3 when you are using the T4?
The only graphics includes I use are:

#include <Adafruit_GFX.h>    // Core graphics library
#include <Adafruit_ST7789.h> // Hardware-specific library

and you might find it works better using initialization for hardware SPI:

Adafruit_ST7789 tft = Adafruit_ST7789(mand_cs, mand_dc, mand_rst);

I used the same init().

Pete

 

[bsandipk]

My code and display worked for T3.2 struggling with T4.

I checked the wiring - it looks ok - the screen has power but is black.

Did you use the makerfocus display and it worked?

Do I need to connect the SCL on 14 instead of 13?
For t3.2 SCK worked on 13 and 14 with relevant assignment in the code, just wondering.

 

[Frank B]

I used a noname st7789 on the t4, with the _t3 library. Had no issues, but I had to use "SPI_MODE2".