@Michael-Hebert if you mean panel like this https://www.adafruit.com/product/420 then I think you can not. This is not SPI device but "12 16-bit latches that allow you to drive the display with a 1:8 scan rate." as described by Adafruit. Also, "Keep in mind that these displays are designed to be driven by FPGAs or other high speed processors: they do not have built in PWM control of any kind." "you'll need 12 digital pins, and about 800 bytes of RAM to buffer the 12-bit color image." Without own driver/controller this panel is silly device.
As an idea only - try to use Arduino based board and Adafruit library as panel controller, and Omega2 as main unit and communicate them using SPI, I2C or UART.
I try this for hours. I don't know. I tried to use crosstool ng to compile evert native npm module for the onion but it is not working. We really need a getting started guid for this or someone who explain this to us how we can compile node native addons for the onion.
But they aren't microcontrollers. They are large embedded systems, or in the case of the Arduino, development boards with a lot of power-wasting components on them compared to using the microcontroller in a way that would be sensible for a battery design.
Also note that MT7688 does not have a crypto accelerator module inside to help the encryption/decryption process thus the poor CPU will have to do the hard labor.
I'd suggest: give that CPU/SoC a break and let it do what it is designed to do; no more and no less.
So, the parts-- I didn't populate any of the internal parts, I am just using the traces from the 2mm holes to the 2.54mm holes. So far so good.
The parts I did solder in were 2mm headers sourced from Amazon which just came in handy. And stacking 2.54mm headers also from Amazon. I used smaller ones and had to sand the ends to get them end to end (I used a 10 & a 4 on one side and two 6 hole headers on the other. You have to sand between or else there is too much plastic between them). Buy the longer ones from Adafruit and trim one side(no sanding).
When checking your conductivity and verifying 0 ohms between the Omega Pins and the stacking header pins-- realize that the power pins are at a 45 degree angle and you'll have to look at the diagram. After that all the pins are nicely labeled by the silk screening on the PCB depending on how good your eye sight is.
Go light on the solder so you don't have it bleed into the stacking header socket side.
Lastly it is a tight fit all around. The Omega 2 barely fits in between the stacking headers. Then when you get it assembled, the whole thing doesn't fit as well as one might hope into the breadboard-- the headers on top come in awful handy.
It made it so easy to hook up, I fried it with 5V before I knew it! But seriously, the boards from PCBs.io are pretty good and this is what I did with a couple of mine...
@Luciano-S @WereCatf told here that the devs of the Omega2 forgot to enable CONFIG_DEVMEM in the newer firmware. The last working one is 0.1.6 b137
So my guess is that it is fixed in the next release if it is indeed just a forgotten flag.