If you need to drive a LED or a relay from a microcontroller, you need a driver circuit.
One of such circuits use a "logic MOSFET" which s controlled by uC logic output, and can switch a larger current (10A) under a higher voltage (up to 60V). I use IRF 540 in such circuits.
Google IRF540 for a data sheet and application circuits. It is simple and you need only a small heat sink for currents >2 A.
I'm not sure why you need a relay to glow an led.
There are very easy methods to glow the led.
1. You can connect the led to uC pin through a resistor.
2. else, Using the transistor or mosfet.
I'm not sure why you need a relay to glow an led.
There are very easy methods to glow the led.
1. You can connect the led to uC pin through a resistor.
2. else, Using the transistor or mosfet.
it is not evident that he can connect the LED to the pin of the microcontroller, it can be that the microcontroller cannot sink the current required by the LED