ESP32 TFT_eSPI 8-bit Parallel Compile Error

Question

I am compiling TFT_eSPI library for Arduino ESP32 in 8 bit parallel mode, When I Compile it in SPI mode then no error occurs, but when I select 8-bit parallel mode in User Setup File, then it shows the error:

c:\Users\yamtech\Documents\Arduino\libraries\TFT_eSPI\Processors/TFT_eSPI_ESP32.c: In member function 'uint8_t TFT_eSPI::readByte()':
c:\Users\yamtech\Documents\Arduino\libraries\TFT_eSPI\Processors/TFT_eSPI_ESP32.c:113:9: error: 'gpio_input_get' was not declared in this scope; did you mean 'gpio_num_t'?
  113 |   reg = gpio_input_get(); // Read three times to allow for bus access time
      |         ^~~~~~~~~~~~~~
      |         gpio_num_t

exit status 1

Compilation error: exit status 1

I already use New Arduino IDE with latest Arduino ESP32 Board by Espressif, but still failure occurs.

Board manager is https://dl.espressif.com/dl/package_esp32_index.json

What i found is that the Newer version of gpio.h does not contain gpio_input_get(), but older version have this function.

Answer 1

In the new esp-idf(V5.x), the GPIO construct is not readily available to all users like it used to be. And there is a related issue on the idf GitHub issues 9184.

As per Espressif, it seems that the (lower-level access of) GPIO was never supposed to be available to users. Instead, it is a low-level library which provides fast pin access by using the pin registers directly. The gpio_input_get() works perfectly fine if the ESP32 Arduino framework is using esp-idf v4.x but may not with esp-idf v5.x core. For some reason, Espressif decided to take it out and make it harder for user to use it.

The TFT_eSPI already have a fix on this and to be roll-out in next release. You can read about it at Issue #2628. In the meantime, you could manually replace the file Processors/TFT_eSPI_ESP32.h in the library with the new one which in the nutshell add the following headers to support the lower-level access of GPIO:

#include "soc/spi_reg.h"
#include "driver/spi_master.h"
#include "hal/gpio_ll.h"

There is also a post in Arduino forum claims gpio_input_get() (still) work by using PlatfromIo, I guess it works because PlatformIo has not upgrade to the esp-idf 5.x yet.