4 years, 3 months ago.

how to shut down LD1 & LD3 on stm32 nucleo F401RE board ? to lower current consumption in sleep mode

I tried to insert these lines in the code:

DigitalOut myled2(LED2); DigitalOut myled3(LED3); myled2 = 0; myled3 = 0;

but this doesn't seem to work...

1 Answer

4 years, 3 months ago.

LD1 & LD3 are part of the STLink interface on the nucleo. This part is used to program (flash) the target F401 device and provide the USB Serial interface to the host. LD1 indicates communication to the host PC. LD3 is a power LED for 5V supply.

You can shutdown the LEDs by powering down the whole STLink part and providing an external 3V3 supply for the target F401. Check the nucleo manual for details.

Accepted Answer