how to setup/configure TFT_eSPI with esp-idf ?

[goutamreddy]

Hi- I have a basic question about how to use it with esp-idf.
TL;DR: Are we supposed to set the TFT settings in menuconfig/sdkconfig or in the User Setup Select file or both?

BACKGROUND
I'm using a LilyGo T-Display. When I was using Arduino IDE, I was able to make the library work by changing the following file:
~/Documents/Arduino/libraries/TFT_eSPI/User_Setup_Select.h
- uncommented #include <User_Setups/Setup25_TTGO_T_Display.h>
- commented all other #include <User_Setup*> files

I'm now trying to use TFT_eSPI with esp-idf.
I git cloned this TFT_eSPI directory into my esp-idf project component directory (~/ESPprojects/hello_world/components/)
I edited ~/ESPprojects/hello_world/components/TFT_eSPI/User_Setup_Select.h as above.
Then, I ran idf.py reconfigure....

When I run idf.py build, I receive a bunch of errors about things not being defined in TFT_config.h:

/Users/xxx/ESPprojects/hello_world/components/TFT_eSPI/TFT_config.h:128:6: error: #error "Invalid Chip Select pin. Check TFT_eSPI configuration"
#error "Invalid Chip Select pin. Check TFT_eSPI configuration"
^~~~~
/Users/xxx/ESPprojects/hello_world/components/TFT_eSPI/TFT_config.h:134:6: error: #error "Invalid Data/Command pin. Check TFT_eSPI configuration"
#error "Invalid Data/Command pin. Check TFT_eSPI configuration"
^~~~~
/Users/xxx/ESPprojects/hello_world/components/TFT_eSPI/TFT_config.h:140:6: error: #error "Invalid Reset pin. Check TFT_eSPI configuration"
#error "Invalid Reset pin. Check TFT_eSPI configuration"
^~~~~
/Users/xxx/ESPprojects/hello_world/components/TFT_eSPI/TFT_config.h:148:10: error: #error "Invalid backlight control pin. Check TFT_eSPI configuration"
#error "Invalid backlight control pin. Check TFT_eSPI configuration"
^~~~~
/Users/xxx/ESPprojects/hello_world/components/TFT_eSPI/TFT_config.h:231:10: error: #error "Invalid MOSI pin. Check TFT_eSPI configuration"
#error "Invalid MOSI pin. Check TFT_eSPI configuration"
^~~~~
/Users/xxx/ESPprojects/hello_world/components/TFT_eSPI/TFT_config.h:237:10: error: #error "Invalid Clock pin. Check TFT_eSPI configuration"
#error "Invalid Clock pin. Check TFT_eSPI configuration"
^~~~~

I noticed there is a KConfig file, which sets up menuconfig items.... and a bunch of menuconfig items appeared:

These options are also listed in sdkconifg file.

I have a feeling these menuconfig settings are conflicting/overwriting the setting in User_Setup_select.h.

If we're using esp-idf, how should we set the settings for use with our display?

Thank you.

[goutamreddy]

Okay, I went through and set all the parameters (as best as I understood) in menuconfig to match those in the file User_Setups/Setup25_TTGO_T_Display.h

`// Setup for the TTGO T Display
#define USER_SETUP_ID 25

// See SetupX_Template.h for all options available

#define ST7789_DRIVER
#define TFT_SDA_READ // Display has a bidirectional SDA pin

#define TFT_WIDTH 135
#define TFT_HEIGHT 240

#define CGRAM_OFFSET // Library will add offsets required

//#define TFT_MISO -1

#define TFT_MOSI 19
#define TFT_SCLK 18
#define TFT_CS 5
#define TFT_DC 16
#define TFT_RST 23

#define TOUCH_CS -1

#define TFT_BL 4 // Display backlight control pin

#define TFT_BACKLIGHT_ON HIGH // HIGH or LOW are options

#define LOAD_GLCD
#define LOAD_FONT2
#define LOAD_FONT4
#define LOAD_FONT6
#define LOAD_FONT7
#define LOAD_FONT8
#define LOAD_GFXFF

#define SMOOTH_FONT

//#define SPI_FREQUENCY 27000000
#define SPI_FREQUENCY 40000000

#define SPI_READ_FREQUENCY 6000000 // 6 MHz is the maximum SPI read speed for the ST7789V`

This seems a bit hackish (to have to redefine everything in menuconfig), so hopefully there is a better way to setup the configuration for esp-idf.

[Bodmer]

The support was added by a user. Have a look at #1770

[goutamreddy]

Thanks for finding that. I understand what happened.

My assesment is that is your code is super dead-simple to use.... just uncomment the specific board you're using, and everything is taken care of re: pins, settings, etc... The user doesn't really need to think through / lookup any of those settings.

With the addition of this KConfig file, the user can now set the options from menuconfig. However, this overrides whatever settings are set in User_Setup_Select.h.

My understanding now is that if you install the TFT_eSPI as a component in esp-idf... it will automatically create the menuconfig options from the KConfig file... and a user IS FORCED TO SET all of those settings themselves in the sdkconfig file.... (e.g. by using menuconfig).

As in, I had to lookup that the T-Display board was board #25, and then find the appropriate settings in the .h files, and then enter them into manually into menuconfig... This takes away from the "seamlessness" of the TFT_eSPI library, but exposes the user to more direct control - I suppose it is a tradeoff- but at the moment undocumented.

My only suggestion would be to indicate to users that to use TFT_eSPI as a component of esp-idf, they can either:

1. manually lookup and enter those settings in menuconfig
   OR
2. delete the KConfig file and run idf.py reconfigure after tweaking the User_Setup_Select.h file (per the normal/usual method).

also- thanks again for building such an easy-to-use library!

[Bodmer]

Instructions added here:
https://github.com/Bodmer/TFT_eSPI/tree/master/docs/ESP-IDF

[goutamreddy]

@Bodmer added a pull request that clarified the instruction file you created-

thanks again for making this library!

[electronicsguy]

Isn't this still using Arduino as a component? Its not pure esp-idf per se, is it?

[mayur9095]

yes, its using arduino as cmponent and its kind of hack to make it work on esp-idf.