On Wed, 30 Apr 2025 Pavel Machek wrote: > > > > > Is it intended to be used as a 4x3 matrix, or is this just an internal > > > > > wiring detail, and should it be exposed as 12 individual LEDs instead? > > > > > > > > The 4×3 matrix is a real and fundamental aspect of the LP5812’s operation. > > > > It is not just an internal wiring detail. > > > > The device adopts a Time-Cross-Multiplexing (TCM) structure, where 4 output > > > > pins control 12 LED dots individually through scanning. Each pin includes > > > > both high-side and low-side drive circuits, meaning matrix multiplexing is > > > > required for proper operation — it cannot be treated as 12 completely > > > > independent LEDs. > > > > > > Scanning is really a detail. > > > > > > If this is used as rectangular 4x3 display, then it goes to auxdisplay. > > > > > > If this is used as a power LED, SD activity LED, capslock and numlock > > > ... placed randomly all around the device, then it goes LED subsystem. > > > > The LP5812 is used for LED status indication in devices like smart speakers, > > wearables, and routers, not as a structured rectangular display. > > Well, IIRC it also supports automated animations, and that does not > make sense on LED indicators. So... what device do _you_ have and how > exactly is it used there? We’re using the LP5812 in a battery-powered smart speaker as a status indicator with visually enhanced lighting — for example, breathing effects during standby and fading effects during voice processing. While the LP5812 supports autonomous animations, they’re used here to offload real-time brightness control from the main controller. Each LED’s animation engine enables smooth transitions like fade-in/fade-out and breathing effects. These patterns are configured once and run autonomously, saving MCU load and power, while still serving traditional indicator roles. Best regards, Nam Tran
