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Topic: LED Brightness (Read 1 time) previous topic - next topic

skyjumper

I'm feeding my Duo with about 6.6VDC, and I find that the PWR and L LEDs are quite dim. Is this normal?

Leon Heller

The LEDs are driven from the 3.3V and are rather dim. Check the schematic to see how much current they are taking.
Leon Heller
G1HSM

Axela

The 6.6v you are feeding the Due goes through a voltage regulator and pared down to 3.3v before getting fed into the chip. The digital pins (I'm assuming you are doing PWM?) are at 3v3, as mentioned by Leon. It is also possible that your resistor (you are using one, right?) may be too large depending on the voltage rating on the LED. Not all leds are created equal.

skyjumper


The 6.6v you are feeding the Due goes through a voltage regulator and pared down to 3.3v before getting fed into the chip. The digital pins (I'm assuming you are doing PWM?) are at 3v3, as mentioned by Leon. It is also possible that your resistor (you are using one, right?) may be too large depending on the voltage rating on the LED. Not all leds are created equal.


Thanks for the reply. I was referring to the PWR and L LEDs, which are built on to the board.

Axela

Ah, so yes, there is a resistor on those. The documentation for the board says that you should feed between 7v-12v through the barrel jack, since the voltage regulator loses a bit when it steps the voltage down. Does it look brighter when you power the board through the USB? (5v, bypassing the regulator, iirc). If not, then, that's how bright they go. ;)

-r

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