3.5 tft lcd for arduino 2560ili9481 in stock

As you can see in the attached photo, I removed resistor R1 which was a “2R0” SMD resistor, which Google says is 2 ohms. The right side of the resistor is a 3.3v supply. The left side goes to the 6 LEDs in the backlight, which then have 6 separate wires going to ground. I didn"t see any other resistors. It"s possible there are some inside the LCD display itself.

I want to control the LEDs via the left pin near “J3” which goes to Arduino pin A5. This pin is not used. When I digitalWrite(A5, HIGH) it is providing 5v, so I figured the resistor would need to be different.

I tried to calculate what resistor was needed but I don’t know the properties of the LEDs. I guessed and checked with an online calculator and decided that 91 ohm looked like it should work. I soldered the resistor between the left pad of R1 and the pin that connects to Arduino A5. It worked, but the LEDs were dim. I dropped down to a 43 ohm resistor and they’re still a little dim but it’s better.

Now is the confusing part. I need to check which button is pressed first, second, third and forth and then probably store the numbers in an array in the order they were pressed. Eventually I will need to compare them to a predefined password which also could be stored in an array. If the input matches the password defined the array the sequence should start.

If the password is correct I want to have a screen showing for example - " Access Granted" and a button - "Close" which will start the closing sequence. Similarly, if the password is wrong I want to have a screen showing - "Access Denied" and then the system should go back to the screen with the password input.

This TFT 3.5 Inch LCD display support 480x320 pixel resolutions. The display uses the ILI9481 graphics controller. The module includes the 5V-3.3V power conversion circuit and no additional level conversion circuitry is required. This Module can be inserted directly into the Arduino Mega2560 Board.