Tips on using the LilyGo T-Display / Touch boards with SquareLine Studio

I have spent several hours today fathoming out what was happening with code generated using SLS on my LilyGo T-Display and T-Display Touch ESP32S3 boards, which were causing no end of issues. Thought it might be beneficial if I wrote up my tips for any other users of these pretty decent ESP32S3 development boards in an attempt to avoid anyone else experiencing the same pain and frustration as I have over the last few days!!. For clarity, for the purposes of these suggestions / tips, I use the ArduinoIDE2 app on a Mac. Also please let it be known I am not a professional developer by any stretch of the imagination, just - as like many of us here I imagine - an enthusiastic self taught wannabe :slight_smile:

The boards I am referring are available here: T-Display-S3 – LILYGO®

They have a pretty decent GitHub page where you can find the factory code and some other examples to try out in your IDE. Squareline Studio makes extensive use of the TFT_eSPI library and it MUST be noted that to use the LilyGo T-Display boards with TFT_eSPI one must use the modified TFT_eSPI library in the /lib folder from the LilyGo T-Display-S3 GitHub page linked above.

  1. Once you have completed your project in SquareLine Studio, and have done the Export > Create Template Project and Export > Export UI Files you will need to replace the TFT_eSPI folder and importantly one additional file.

  2. Replace the folder…


… with the one downloaded from LilyGo GitHub repository

  1. Repalce the file…


… with the one downloaded from LilyGo GitHub repository

  1. You may have to edit the lv_conf.h file to ensure that line 30 shows:

#define LV_COLOR_16_SWAP 0

  1. Launch your-project.ino file using ArduinoIDE

  2. I have found and reported an issue/bug in the Squareline Studio generated code for your-project.ino file, typically on line 18 or thereabouts look for a line with the following:

TFT_eSPI tft = TFT_eSPI(screenWidth, screenHeight); /* TFT instance */

Then change that to:

TFT_eSPI tft = TFT_eSPI(); /* TFT instance */

…and save your file

  1. Ensure you have changed your Sketches Folder in Arduino>preferences to the location of your newly created SLS project folder

Your code should then compile and upload successfully. Now I appreciate this in not the best solution but it does allow you to use these boards with SLS. Be aware that if you re-export your template files from SLS you may have to once again repeat steps 2-4 above.

NB: it should also be noted that if you use either of these boards outside of SquareLine Studio, you also need to ensure you are using the correct TFT_eSPI library and lv_conf.h file from LilyGo in your Arduino/libraries folder.

I created a quick demo project in SquareLine Studio to check this, here’s a screenshot from SLS;

and the resulting (poor quality) photo from the board itself…

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Thank you very much for sharing your experience. I’m sure it will be useful for many people.

We are visiting Embedded World this week and I’ll check if I can meet with the guys from LilyGo.

You are very welcome, and have a great conference, hope you make loads of useful contacts.

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