esp32 arduino tft display quotation

were missing for my display (hailege, 2,8 tft, spi, il9431, https://www.amazon.de/-/en/gp/product/B07YTWRZGR/ref=ppx_yo_dt_b_asin_title_o04_s00?ie=UTF8&psc=1). so it might just be that the led backlight isnt being turned on. but of course the tip might not help with the st7796s.

At the beggining I thougth it could be the image conversion but all the files of the TFT_flash_jpeg example presented the same gliteches an color distortion.

Other issue that"s making me crazy is that when I work with tft.invertDisplay(0); my tft.fillscreen(tft_WHITE) makes the screen goes light green, but if I invert the display and fillscren(tft_BLACK) it turns a clear white screen...

This project uses the SPIFFS (ESP32 flash memory) to store images used as background. You"ll need to upload these to the ESP32 before you upload the sketch to the ESP32. For this you"ll need the ESP32 Sketch Data Upload tool.

You can download this from Github: "https://github.com/me-no-dev/arduino-esp32fs-plugin". Follow the instructions on the Github to install the tool:Download the tool archive from releases page.

Before you upload the data folder to the ESP32, you"ll first have to select the right partitioning scheme.Go to Tools -> Board and select ESP32 Dev Module.

Extract and rename the extracted folder to "Bluetooth-System-Monitor". This is so the Arduino IDE does not complain that the folder and the sketch do not have the same name. If this happens, you will get a popup asking you if it should move the sketch. The dangerous thing here is, that it will only move the sketch and not the Data folder. This will result in errors when uploading!

Firstly, depending on the board you are using (with resistive touch, capacitive touch, or no touch) you will have to uncomment the correct one. For example, if you are using the ESP32 TouchDown uncomment: "#define ENABLE_CAP_TOUCH". If you are using a DevKitC with separate TFT, uncomment "#define ENABLE_RES_TOUCH".

You can also set the scale of the y-axis of the graphs. This is done under "// The scale of the Y-axis per graph". If these are to big or to small, the data will not be displayed correctly on the graph. You might have to experiment with these.

Go ahead and upload the Bluetooth-System-Monitor.ino sketch to the ESP32. The settings under tools besides the Partition Scheme can be left to the default (see image). Go to "Sketch" and select "Upload". This may take a while because it is a large sketch.

I"ve tested the TFT_eSPI-Library with an ESP32 DEV Module (ESP-WROOM-32) and a 2,8" SPI TFT Module with ILI9341 without touch. Everything was fine. For cabling and setup i used the Youtube-video from XTronical "ILI9341 TFT LCD to ESP32 -Full HOW TO ..."

Those results indicate there is no communication happening with the display chip for some reason. Since the TFT_eSPI library is not used for the test this indicates that the library will not be able to talk to the chip either.

This might not work but try it: The displays are fitted with a regulator (U1 on PCB) which is designed to accept 5V input and output 3.3V to the display. These are normally "Low Drop Out" (LDO) which means that if you connect 3.3V to them they still output about 3.0V and this is sufficient for the display chip. Your board may be fitted with a regulator that has a higher voltage loss, so it is worth trying to power the display from 5V connected to the VCC pin. The other option is to bypass the regulator U1 by soldering a link (or adding a big blob of solder) to short across J1 pads. This then links VCC direct to the TFT chip and thus VCC must only be 3.3V (5V with that link will damage the chip).

It may be the display chip has been blown by accidental connections during testing and debugging, but I have found they are quite robust to moderate abuse.