What does LD3 and LD1 do on a STM32 Nucleo?

Oct 21, 2025 · 4 min read · LD1 and LD3 are user LEDs on the Nucleo board, but they serve two very different primary purposes. Here’s a detailed breakdown: LD1: The System Status / Communication LED Color: Green This is the more complex of the two LEDs. Its behavior is control...