maybe these components are not compatible after all

[JungleJim440]

Rather than bore you all with the many rabbit holes I have been down trying to make this work I shall simply list the major hardware components and perhaps I can get some feedback from the more experienced than I on whether or not I am doomed to fail. [ others have surely been here before me ]

I am using an ST7796S based 3.5" TFT display upon which I can run simple graphics tests with Adruino_ST7796S_kbv.h
I would like to use some sprites on this 320x480 TFT display so ultimately I am thinking about TFT_eSPI.h
and...as this display supports capacitive touch, that too be a road I shall crawl down at some point.

I am using a RPi Pico (for me a big set up from an Arduino UNO or NANO)

I am programming with the Arduino IDE
my code validates, and based up some serial print messages along the way my void loop() is marching along as expected.

Thus far I have NOT been able to execute so much as a successful "tft.fillScreen(TFT_RED);" when using TFT_eSPI.h
I have been just fine with a "tft.fillScreen(ST7796S_GREEN);" when using Adafruit_ST7796S_kbv.h

thanks ahead of time to any and all who politely choose to help me pull my head of of my arse :)

the attached text file is for the "myCustom_Setup" file created in compliance with Bodmer "TIPs" section as a guide,
and which is being call upon from within TFT_eSPI "User_Setup_Select" as shown here
" #include <../TFT_eSPI_Setups/JimiG_RPiPico_ST7796_custom_setup440.h> "

JimiG_RPiPico_ST7796_custom_setup440.txt

[Bodmer]

GPIO 19 is MOSI
GPIO 16 is MISO

You have these swapped at the moment. The other alloations look good. BTW, you need to use Earle Philhower's RP2040 board package.

[JungleJim440]

Thank you for the unexpectedly rapid response.
I do indeed have Earle Philhower's RP2040 board package(v3.6.2) loaded up within my Arduino IDE board Manager.(v2.2.1)
The pin arrangement as-is works with Adafruit_ST7796S_kbv.h, but I went ahead and tried swapping in the custom setup file for TFT_eSPI anyway. no change. hmmm....

I will be away for a couple of days, off to meet my new grand-daughter.
I shall re-visit this little project when I get back.

[Bodmer]

Adafruit_ST7796S_kbv may bit-bash the SPI signals so that is why it works. The hardware SPI however needs certain pins to be used and GPIO cannot be used for MOSI. See here for default pin allocations (MOSI - SPI0 TX).

You can use any pins if you invoke the PIO implemented SPI port. Add following line to the setup file:
#define RP2040_PIO_SPI

Run the Read_User_Setup sketch and look at the serial output to see if the correct settings are being picked up by the compiler. A common mistake is to forget to coment out this line.

[JungleJim440]

Sorry for the several days delay in getting you this response. I returned home to several days without electricity/phone/internet caused by heavy storm damage in the area. Thank you sir, "#define RP2040_PIO_SPI" did the trick. I am off to the races !