ILI9327 Open Smart 3.2 TFT display and Arduino Mega: manage Backlight

Other Hardware Displays
1

Continuing the discussion from White screen - Using TFT 3.2" LCD shield (ILI9327) on arduino Mega 2560:

my sons gave me a 3.2" Open Smart display with ILI9327 and an Arduino Mega board.
Only after reading david_prentice suggestions, on various websites, did I understand how to make it work, making some changes to the MCUFRIEND_kbv.cpp library.

I managed to create a project, using a BME280 sensor and an RTC DS3231, which shows on the display the date (day, month and year), the hour and the minutes, the current temperature, humidity and pressure, and the respective minimum and maximum values.

In addition, using the micro SD on board, I have added the record of the date and of the minimum and maximum values ​​of the last 24 hours, every midnight.

Since there is an area on the display card with indications relating to the backlight, I would like to ask somebody, and David_prentice, in particular, how to use it to turn off only the display backlight during the night.

Could anybody show me the necessary connections and the instructions to add to the sketch? In the post #11, david_prentice says to use two resistors to reduce the signal from 5V to 3.3V, but I don't understand how to make the connections and to what.

I'm not a great expert, and I'm afraid of damaging everything.

I hope somebody can help me (maybe david).

P.S. I posted the project on https://www.instructables.com/Build-a-Clock-a-Calendar-and-an-Accurate-Thermomet/

2

Hi!

From I can understand it should be like this:

backlight
backlight1125×959 79.2 KB

You have to check which side is connected to D3 using a multimeter in continuity option.

Also remove the solder bridge between 3.3 V and backlight next to ICSP header.

tft.jpeg
tft.jpeg576×1024 117 KB

Best regards.

3

Thank you, very, very much.
I'll try later...

4

Hi,

I followed your clear hardware directions and made small additions to my sketch and now I can turn off the display backlight.

I also added a pushbutton between D2 and ground and a 10k resistor between D2 and +5V, with a further addition to the sketch, and so, when the backlighting of the display is off, pressing the pushbutton I can activate it momentarily.

Thank you very much for your help.

I posted this project on https://www.instructables.com/Build-a-Clock-a-Calendar-and-an-Accurate-Thermomet/

Here attached is the last version of my sketch, with the backlight control.

Greetings
Giuseppe

ILI9327_Arduino_Mega_data_Temp_Umid_15_3_2023_Pulsante.ino (14.3 KB)

5

Glad to hear!

You can mark the post above as solution.

6

Thank you for your support!

7

Well, I was talking about my post. :rofl: