Hello, I would like to know if it’s possible to run 2 separate dot matrix displays with one Arduino uno, haven’t seen much in the way of videos about it, most people only use the one (daisy chained together) but I would like to have 2 separate arrays of daisy chained modules with separate information, to be more specific and to add context they’re replacing 2 analog gages that go to separate pumps that read pressure. Thank you 
That ought to be possible. Either use 2 instances of code, or a chip select and alternate between the 2 units.
Im just unaware of what pins to use to send the data to the 2 screens, the guides I see online give me the pins for one screen, and I assume I can just jump the CLK wire, and I don’t have to worry about power because that’s gonna be coming from a separate buck converter. I’m very new to this (my first project to be exact) and I don’t know if the Uno has 2 pairs of CS and DIN pins
Edit: from what I’ve seen after looking at a couple other posts the pins; 13, 12, 11, 10, are all connected to the hardware SPI and are all digital outs, so in theory if I use 13 and 12 for one display then 11 and 10 for the second display that should work, then just jump the CLK wire?
Edit pt.2 I saw that the pins would have to be 13, 11 for display 1 and 12, 10 for the second display because polarity
As I know SPI for several units is possible. Just use 2 selecting pins for the 2 units.
That makes no sense at all.
First off how big is this dot matrix display in terms of the number of LEDs? This is because you need to store two of these bit patterns and if it is too big for the Arduino memory you have then it is not going to work.
Second, the SPI bus is just that a bus. That means you can connect all the pins to all the devices except for a chip enable pin. Each device needs its own chip enable pin. This is driven low if you want the SPI bus to talk to that device and high when you don't want to talk to it. So no two devices are active at the same time.
Third, what does the multiplexing of the two displays? If it is external hardware then that is fine. If it is software then you might have an issue with flickering.
Any free pin can be used as a chip select pin. There is only one set of pins for all the rest of the SPI pins.
Not just videos, Google;
dot matrix display arduino
Tom... 
I successfully built a LoRa project based on Some tutorial, with a transmitter on my balcony and a receiver displaying the temperature readings in the Serial Monitor. However, I'm facing a challenge in connecting a dot matrix LED display to show the readings with time and date. The original project used pins 3, 11, and 13, but these are occupied by my LoRa project. I tried redefining the pins, but it didn't work. Before troubleshooting further, I want to clarify if it’s possible to use different pins for the LED display, or if I need to use the original pins specified in the tutorial. Any insight on this would be appreciated!
I am using Arduino Nano 33 IoT and 1088AS LED display
#define CLK_PIN 9
#define DATA_PIN 8
#define CS_PIN 10
I figured it, thanks, guys.
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