What are the types of displays?

So I'm trying to find a display to use with my new project.

The problem is I'm already using two spi devices and I want a larger screen up to 5ish inches, less then 2 inches wont work. I don't need touch or anything fancy.

What are my options? From my understand I would need a i2c display. Are there any others i dont know about?

I know nextion uses tx and rx but I'm not sure it that's a spi device or not. I wouldnt call displays my strongest skill lol.

Thanks for any help anyone can give.

I know nextion uses tx and rx but I'm not sure it that's a spi device or not.

Tx and Rx are serial. Nextion uses serial, not SPI.

Tx and Rx are serial. Nextion uses serial, not SPI.

So there is spi, i2c and serial displays?

So that means if I have 2 spi devices already I could have either a i2c or serial display and these would not mess with the spi devices?

If so that's good to hear. I just need to find a larger serial or i2c. I just dont really want to use a nextion display but it looks like I probably will have to.

I am not an expert on displays generally, there are people on here better than me for this. Yes, there are I2C, SPI and serial displays, I don't know which are which. You should be able to use multiple SPI and I2C displays, but someone else will tell you how, sorry.

In theory you can use multiple SPI displays, I2C displays, UART displays, Parallel displays.

In practice you have to be a bit careful. Several popular displays have "features".
e.g. ILI9488, RA8875 SDO pin does not 3-state properly.
e.g. RA8875 I2C interface will be SLOW for some operations
e.g. parallel SSD1926 uses a lot of GPIO pins

Actually the Nextion displays might be suitable for you.
I have never used Nextion. Perry Bebbington can offer good advice.

All TFT, OLED electronics expect 3.3V logic. This gets complicated with 5V Uno, Nano, Leo, ...
As far as I know, Nextion is happy with 5V logic.

Larger Arduinos have multiple UARTs. So you have can have a dedicated hardware Serial for your Nextion.


I have a bad habit of making stuff way more complicated as soon as I attach a nextion lol.

I was hoping to use one that's not touch to force me to keep this simple. But seeing how my spi will be used with two devices already I'm not left with much options. I2c displays are way to small. So serial i guess would be my only real option.

I'm making a thermometer/hydrometer with 6 slaves (as sensors) each sensor will be a nano, a dht22, a nrf24l01, a spi oled and a photocell resistor (no light detected screen stays off).
The master will be a uno, dht22, data logging shield (rtc, sd logger), a nrf24l01 and I suppose a nextion display.

Thanks guys