35mA led with 25mA pic output?

[xnihilo]

It may be that the 35mA rating for the LED you describe is a maximum, do-not-exceed rating. If you can find the data sheet for the LED, see if it also gives a typical operating current.

People sometimes forget that most LEDs will produce full brightness long before maximum rated current is reached.

A couple of replies have suggested a 220 ohm resistor; that or even a 180 ohm resistor would be a good starting point. Depending on the Vf of the LED, that will give you something between 14 and 19 mA. You may be surprised to find that the LED is quite bright.



Piezo tone/buzzer devices are basically voltage-driven; the greater the voltage, the louder the sound. The 9 mA rating is probably for the 12 VDC maximum; at 5 volts, it will likely draw only 4 or 5 mA.

They say "max dc forward current" and "Typical" FC is 35 mA
See: http://www.futurlec.com/LEDR3R.shtml

About the buzzer, thanks for the info, I'm surprised it needs only 9mA (7mA in fact) at 12V. That's cool.

I lear so many things here.