Bare display board schematic ILI9341

Other Hardware Displays
1

Hi,
I've ordered bare ILI9341 for my project, I plan to connect ESP32 to it.
I had to design a board, I've drawn an schematic, can someone have a look to see if I connected everything how it should be.

Link for display ( documentation in description)

In the specs it says operating voltage 2.8V- 3.3V
I plan to use Diodes to reduce the voltage a bit ~0.5V

On the schematic left side is Display with pin association 1-40, FPC connector (1-40) and on the right i plan to use JST (4) pin x3 to connect this board to my esp32

Can someone have a look at this this will be my first pcb ever, and first bare display.

I'm not sure if these pins should connect anywhere
17-32 DB0-DB15 - Data Bus
33-36 I think i should power this with 2.8V?
pin 38-40 - Select interface ? Dont know what these are for
Pin 8 FMARK?
Pin 12?

Also Is there any differences between FPC connector top mount, bottom, bottom&top ? Like are there all backwards compatible with the ribbon cable?

2

That works but you need a small load on it otherwise the diode leakage will pass the full voltage. The display may be enough of a load, I am not familiar with it. I would suggest some high frequency bypass caps such as 100nF. Other then that it looks ok. I did not check pinout.

3

Should I place a 100nF capacitor before the diode or after?
-Ah I see i cant place it inline. I need somehow to connect it to + and to gnd

I think i've figured out the connections. IM pins detrimine the interface and have to be connected.
Just the part that I dont know is how to add a this capacitor can I put it like on the same trace whit the diode?

4

As close to the IC as possible. A good ground is important.

5

I appreciate the feedback
I Grounded all unused pins, and connected the ones that I will be using.
Also I've noticed that backlight is (3.2V) - (3.4V max). I've added a 10kOhm and 320kOhm resistor to bring it to 3.2V. - Is it ok to have only one of these, instead of having each separate one for every trace ?

I've also added a 10nF capacitor as you recommended.
I'm not sure if I've wired in this correctly, can you have a look?

If this is correct, I would place the capacitor as close to the connector as its possible.

Is this OK ?

I actually think I need R1 to be = 1.1kOhm, and R2=32 Ohm
In datasheet is says

Ah i can run a simulation in this software its cool, i can check it that way

6

Looks good. I wou8ld also add one on the line where the three diode anodes connect.

7

Thank you!