If you configure an addressable LED to red (for example) and you switch off the power, will it light up again in red when power is switched on again? Or will all lights be out after a power interruption?
Is there a way to obtain such behavior?
I did not buy a addressable LED strip yet but I'm planning a project. I would like to use addressable LEDs as an important orientation lighting, but I also want to be able to do some fun stuff with the same LED's. It would be great if the LEDs stores their last configuration when switched off:
- when they are switched on, they would react faster. And I do not have to keep the microcontroller on standby all night.
- it seems a lot more reliable when I am able to work without a microcontroller in the loop.
Thank you for your help. I could not find the answer.
The colour of the LED is stored in you Arduino memory.
If you have a small number of pixels you could save these pixel colours in EEROM then retrieve them on power recovery.
Why do you need to recover the colours over a power fail?
I do not want to keep a specific color, I just want them to light up on power on without sending out the addresses and settings via the data pin.
Actually I want the best of both worlds: the simple on/off behavior of a normal RGB strip and sometimes the versatility of an addressable strip.
Thanks for your reply, I implicitly read that an addressable LED never lights up on power on.
You can power up and turn on WS2812B addressable LEDs very fast.
How many LEDs are you planning to have.
This is not possible - you can have the arduino remember the state (via eeprom) and load that up on startup, but the LEDs themselves do not remember state on power cycle, and sometimes when power is first applied, the first led assumes a random color.
, I implicitly read that an addressable LED never lights up on power on.
While the LEDs will never light up with what you programmed last, some times on power up all the LEDs come on at once with the same colour.
I am not sure why this happens but it could be when you turn the power off and back on again quickly. The LEDs might be kept in some sort of limbo state for a time by the small voltage on the large capacitor. But it also might be due to the rise time of the power supply.