On/Off LED help request

  • Hi,

    I have one of these buttons http://www.maplin.co.uk/p/230vac-3a-ip67-blackblue-illuminated-push-switch-n27ka and wondered if it was possible to get the LED to work with the Pi.

    It's listed as "230VAC 3A IP67 Black/Blue Illuminated Push Switch" with a rating of "3A AC 250V" and 12v dc. I'm guessing this is too much for a Pi to power from the 3.3v GPIO pins but if anyone knows if it can be done, and what resistor I'd need I'd love to know - I don't understand any of this stuff!


  • Hi,

    What you're trying to do is a little more complex than what you think. My electronics memories are a little far, but you'd need something like that, with a NPN transistor instead of a PNP i think, with the gpio being at the base of the transistor, the upper voltage being 12V (that you need from a power supply), and calculate intensities so that you can set the resistors values

  • @subs Thanks for the info. I don't want to add a 12v power supply just for an LED so I think Ill just use the button without the LED, and look for a 3v power button/LED to replace it with in the future.

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