Alright guys, here it is:
The size of the overall unit is roughly 120mm x 210mm
there are:
rectangular LED matrices for digits, each of those matrices looks to be 5 x 10 LEDs (3 of them) and is 6.5mm x 3.2mm, the larger one is 5 x 20 LEDs. And there's x 8 of these arrangements for the whole unit. I'm estimating that each LED needs to be 0.5mm x 0.5mm in size and positioned as I mentioned very closely together.
These digit matrices are surrounded by a ring of LEDs. For the top two indicators, there's 2 rings of 2 different coloured LEDs (green and orange), for the bottom 6, there's just 1 ring.
The ring of green LED's is composed of most likely 3 LEDs which are connected in series, because all three on each radial are lit at the same time. The outer ring has 4 orange LEDs lit at the same time which straddle the inner ring. As the digits change, the radial that is lit up changes also, CW for increasing values, CCW for decreasing values.
I'm estimating that these LEDs can be 0.6mm x 0.3mm.
The segment displays have 2 LEDs per segment and I'm estimating that these are the same size LEDs as those on the rings.
These segment displays are different to the ones I'm trying to make in this thread:
https://www.eevblog.com/forum/projects/make-my-own-7-segment-display/msg1423366/#msg1423366That thread is for another project.
So to summarise, there are 3 types of LEDs necessary for this project:
0.5mm x 0.5mm green LEDs, 0.6mm x 0.3mm green and 0.6mm x 0.3mm orange LEDs.
Here are the problems:
1.) Down the bottom, there are buttons and knobs. If I use a TFT or OLED display, I'm not sure how I'll be able to mount buttons and a pot in a slim enough fashion over the the screen.
2.) If I use a TFT/OLED display (I already have a TFT display that I can use to display all these things and in fact after doing the search, I even found a better one), HOWEVER, the problem is that although it's possible to find a screen with an appropriate active area, the problem then becomes - the instruments that straddle my gadget. The metal casing will protrude out and overlap with the adjacent instruments, which is not ideal. Workable, but not ideal.
So ideally, it would be nice to actually make my highly complex LED matrix and have the unit totally fit within it's footprint. This is the main reason why I'm trying to do it the hard way because having a TFT display stuff up all the adjacent unit positioning.
EDIT & P.S.: I looked over the available OLED/TFT displays on digikey and none of them were of the right size. I need square ones, but they are all rectangular. So if you put them side by side, then they overlap in inappropriate places.