user42707: I'm writing a SPI Master module for my FPGA and I would like test it with my Arduino Uno.
What's the problem? My FPGA has 3.3V logic and Arduino has 5V TTL logic.
So, what's the simplest solution to convert 5V TTL logic into 3.3V logic?
I know this topic has been already discussed in many sites but I can't find an unified answer.
Thanks in advance!

user37523: You can get 5, 4 channel bi-directional logic level converters for less than $1 USD Logic Level Module
Not only will they "translate" 3.3V to 5V and 5V to 3.3V, but they also work with higher voltages as well. For example, a vehicle with a 12V electrical system to 5V and vice versa works too.

42707: <p>I'm writing a SPI Master module for my FPGA and I would like test it with my Arduino Uno.
What's the problem? My FPGA has 3.3V logic and Arduino has 5V TTL logic.
So, what's the simplest solution to convert 5V TTL logic into 3.3V logic?</p>

<p>I know this topic has been already discussed in many sites but I can't find an unified answer.</p>

<p>Thanks in advance!</p>
 37523: <p>You can get 5, 4 channel bi-directional logic level converters for less than $1 USD <a href="https://www.aliexpress.com/item/5PCS-IIC-I2C-Logic-Level-Converter-Bi-Directional-Module-5V-to-3-3V-For-Arduino/32216849765.html" rel="nofollow noreferrer">Logic Level Module</a></p>

<p>Not only will they "translate" 3.3V to 5V and 5V to 3.3V, but they also work with higher voltages as well. For example, a vehicle with a 12V electrical system to 5V and vice versa works too.</p>
