Most compact solution for 48 RGB LEDs on round pcb

[bozzaglia]

Hi,
I would like to design a PCB with 48 smd LEDs (preferably RGB but bi-color could be an option) soldered on the outer rim.
I am thinking about using a QtPy board to control it, soldering it in the center of the pcb.
I need to keep this as compact as possible so I was studying my options. As I understood so far I could:
1) use addressable LEDs (I believe the 1515 neopixels are the absolute smallest) and a very simple circuit. I think this solution is much simpler but also more expensive.

2) use regular RGB LEDs and a multiplexing circuit. A little more complicated but cheaper.

I haven’t studied the circuit details for the two options but I am assuming that option 1 would allow me to place the LEDs almost touching one another (so definitely less than 100mm (10cm) circumference of the board) while option 2 could require a little more space for the traces (but I found rgb LEDs as small as 0.5 x 0.5 mm), and definitely more space on the board for mosfets and possibly other components needed for the multiplexing (I ruled out charlieplexing because I need to light more than one led simultaneously). If I knew I could stay below 100mm board circumference with option 2, I would definitely go for that one because it’s cheaper.

Did I understand correctly so far? Is there any other factor that I should consider to decide which way to go? I am a little confused by the fact that pre-soldered rgb led circles are all bigger than the size I am thinking about…

Thanks in advance.
Angelo

[mikeysklar]

Angelo,

There is an Adaruit triple ring 44 RGB LED board that would be easy to drive with a QtPy and appropriate power supply.