2 RPi Zero W to 1 SPI 2.8" monitor

[antolanca]

Hello everyone. I'm wanting to build a visor using 4 Raspberry Pi Zero W, 4 cameras (2 IR, 2 Thermal) and 2 monitors smaller than 3" each. However, all monitors I can find below that size are all connected in SPI instead of HDMI  . Now the Pi has only one camera input hence why using one per camera (I can use usb but then would lose FPS which is important on a visor. At least it's what I've read online) and I am happy to use the SPI connections.
However, so far no one has been able to explain to me as to how can you connect a switch in order to switch from displaying Pi 1 to displaying Pi 2.
And even Youtube videos explaining how SPI works don't actually give me any ideas as to how can I switch from one to the other.

If anyone could explain to me how it actually works and how can I switch from one to the other (in very lay man terms please) I would very much appreciate it.

Thanks in advance.

[ogden]

Forget about SPI display it is slow. Search resulted in <3" RPi display, so they exist. You just have to search them:

https://thepihut.com/collections/raspberry-pi-screens/products/adafruit-pitft-2-8-touchscreen-for-the-raspberry-pi

[antolanca]

That display uses SPI.

"The plate uses the high speed SPI interface on the Pi and can use the mini display as a console, X window port, displaying images or video etc. Best of all it plugs right in on top!
The plate uses the high speed SPI interface on the Pi and can use the mini display as a console, X window port, displaying images or video etc. Best of all it plugs right in on top!"

But what I actually need is a switch.

[tsman]

You say "2 IR, 2 Thermal" but there isn't a thermal camera module that is compatible with the CSI interface on a RPi so you're down to only two cameras across two RPi Zero boards. If you're using the NoIR RPi camera then be aware that the colours for some things are all messed up since it is lacking the IR cut filter.

[ogden]

That display uses SPI.

Ouch, how did I miss that. Sorry. I thought that all their displays have DPI interface

[Kasper]

You say "2 IR, 2 Thermal" but there isn't a thermal camera module that is compatible with the CSI interface on a RPi so you're down to only two cameras across two RPi Zero boards. If you're using the NoIR RPi camera then be aware that the colours for some things are all messed up since it is lacking the IR cut filter.

Its easy to add a switchable IR cut filter.
Google 'ir cut filter switch'
And should probably get an illumination sensor too so you know when to switch the switch.
And maybe some IR LEDs too but be careful with those, they can be high enough power to damage eyes while not being visible.