I am planning to install series of APA102 addressable RGB LED strips along the perimeter of my garage (just below the ceiling, not visible directly but illuminating the area where the ceiling and wall meets). The total length of the run (interrupted by some doors and other objects) is about 36 meters.

I am looking how to power it. It comes in reels of 5m, it appears that at full brightness it is still not enough to be powered just at both ends, as the white brightness starts turning amber after about 2 meters, returning back to white at the 4th meter. So, I plan to supply power at every 2.5 meters.

Regarding the APA102 clock and data lines, there should be no problem, as the signal is fresh at every output. But I am afraid if just running a 5V power line along the strip, supplying it at 2.5 meter periods, will be enough, as the voltage would drop along the power line that goes up to 20 meters (assuming I have the power adapter somewhere in the middle). How I can ensure stable 5V supply along the whole route? Just throw more adapters at it, connecting, say, 3 of them them in parallel, at 6th, 12th, and 30th meter?

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    \$\begingroup\$ The way I would go about this is to determine your current draw of the LEDs, the acceptable Voltage drop you are happy to allow, and then determine the thickness of cable you would require to transport this current to have an acceptable voltage drop. Then if the cable expense is above placing more power supplies, then place more power supplies \$\endgroup\$ – Makoto Jan 29 '18 at 7:33
  • \$\begingroup\$ Do you really need 36 meters of addressable leds? Also keep in mind that most libraries have a maximum number of leds that it can keep track of. And yes you simply parallel adapters. \$\endgroup\$ – Passerby Jan 29 '18 at 7:36
  • \$\begingroup\$ @Passerby the APA102s can be used with Raspberry Pi's (because SPI). if you do use a Pi there isn't the same memory limitations which is pretty rad. But ya, 36 meters is a proper installation \$\endgroup\$ – Makoto Jan 29 '18 at 7:42
  • \$\begingroup\$ @Passerby APA102 standard is much more friendly than the popular WS2812 one. APA102 can is driven by simple SPI, so a cheap microcontroller can do all the driving. The protocol is quite simple, so it's not hard to write my own library. Your question whether I really need 36 meters of addressable leds, is rhetoric one. Perhaps I don't. But it's cool to have total control over light in different ends of the room. And did I mention animation? \$\endgroup\$ – Passiday Jan 29 '18 at 14:51
  • \$\begingroup\$ It's not the spi part, it's the memory tracking for n number of leds while keeping it up at x framerate. \$\endgroup\$ – Passerby Jan 29 '18 at 15:06

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