user13555: I followed instructions to get my TFT to work.

I want to use other pins on the Arduino Uno for other I/O, so how can I use 4-bit data transfer for the TFT touchscreen?

user4143: You read the datasheet for the chip that is on your TFT display (whatever that is) and find if it even supports a 4-bit mode.  It probably doesn't. I have a large number of TFT screens here and I don't recall any of them using parallel 4-bit.  It sounds like you actually want a TFT screen that works of SPI rather than a parallel interface.  Those are available, but by using SPI the screen updates are considerably slower.

13555: <p>I followed instructions to get my TFT to work.</p>

<p><a href="https://i.stack.imgur.com/VtD3P.jpg" rel="nofollow noreferrer"><img src="https://i.stack.imgur.com/VtD3P.jpg" alt="TFT photo"></a></p>

<p>I want to use other pins on the Arduino Uno for other I/O, so how can I use 4-bit data transfer for the TFT touchscreen?</p>
 4143: <p>You read the datasheet for the chip that is on your TFT display (whatever that is) and find if it even supports a 4-bit mode.  It probably doesn't. I have a large number of TFT screens here and I don't recall any of them using parallel 4-bit.  It sounds like you actually want a TFT screen that works of SPI rather than a parallel interface.  Those <em>are</em> available, but by using SPI the screen updates are considerably slower.</p>
