i did a setup with ESP32 NodeMCU and a 2.8" SPI Touch ILI9341 with SD card.
Correct name: ESP32 NodeMCU Module WLAN WiFi Dev Kit C Development Board with CP2102
Currently i connected the LED pin of the display to the 3.3 V pin of the ESP32.
However, i am wondering if i can turn on / off the display via code.
One possibility would be to connect the LED pin to a GPIO pin and set it to OUTPUT.
I measured the current between 3.3 V pin and LED pin and its only 2.4 mA. This is really surprising me! Is something wrong? I thing the GPIO pins are capable of ~40-50 mA?
Other possibility would be to use a transistor i suppose. Which one should i chose? (however i want to avoid this due to package reason).
I am using the TFT_eSPI library and didnt find any command to control brightness or on / off. Is there a command?
thank you for your response!
I do understand the first part
Connect LED pin to a regular 3.3V GPIO pin.
So you mean i can just connect it to a digital GPIO (for example D16)?
I am wondering why the measured current is so low? I would expect higher values (maybe 20-60 mA?). I am afraid that i do something wrong and damage the ESP32.
The second part i do not understand:
Q1 is the backlight transistor. U1 is the 3.3V regulator chip.
Not all Red SPI boards contain Q1. Your photo shows U1, Q1, XPT2046.