Tuning the drive strength doesn't change the LED current by a whole lot. I collected some data a few months ago to compare against WS2812 current draw. This is for a green LED from the junk pile:
The degree of control is limited to a range of 2X current, so for dimming, PWM is still the way to go. To compare, a WS2812 on a RP2040-Zero draws about 16.6 mA with 0xFFFFFF (white) at 5V (15.5 mA for 3V3), and each colour draws about 5.3-5.6 mA.
While Charlieplexing works for an indoor setting, it may well wash out when outdoors in sunlight.
Code:
Green LED (3mm clear)- both pins connected to GPIOGPIO drive LED+ LED- V(LED) I(LED)-mA---------------------------------------------- 12 mA 3.10 0.14 2.96 8.28 8 mA 3.08 0.14 2.94 7.32 4 mA 3.05 0.16 2.89 4.99 2 mA 3.03 0.18 2.85 3.59----------------------------------------------While Charlieplexing works for an indoor setting, it may well wash out when outdoors in sunlight.
Statistics: Posted by katak255 — Thu Feb 26, 2026 2:14 am