I've got a 2.2 SPI monitor (QVGA TFT monitor & SD Card), but I am using Arduino UNO board. All pins are 5V. How can I use a resistor to communicate between TFT, SD and UNO?

I have lots of different Ohm resistors, and have 3 Logic Level Converter (non bi-direction).

2 Channels LLC

I try the LLC connect to TFT, but no luck, it just has the backlight ON, nothing I can see.

Thanks TJ, I had wired with this circuit, but the voltage seems not enough 3V. Am I something go wrong?


simulate this circuit – Schematic created using CircuitLab

Also, I have try to change R1 to 330 ohm & R2 to 680 ohm. Seems also cannot convert to 3V / 3.3V


1 Answer 1


You can use a simple voltage divider to make 3,3V from 5V. 3,3v is high enough for the arduino to detect it as a high input.

Take for r2 470 ohm and for r1 220 ohm.

  • \$\begingroup\$ Thx, but I use 100 ohm for R1, 200 ohm for R2. Thanks \$\endgroup\$
    – Allen Chak
    Dec 29, 2014 at 15:06

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