Very beginner LED control question.



  • Apologies in advance, as I realize this is probably a very basic question. But to the point.

    I have a 5v 5w single channel LED light that I would like to control (dim on/off). But if I understand it correctly that would be a power draw of 1 amp which is more than the Atom can handle?

    Is there an i2c module (or something simple) that I could supply external power to and would work with atom to do this?

    Thank you.



  • No, you need a driver circuit to control the LED. also the pins are 3.3v not 5 volt and can only supply something like 20 to 30 milliamps.



  • you could do on/off via relay module but no dim option with it then



  • Thank you! And a follow up beginning question. This is for a micro aquarium controller (think big beer can size) so I was already using relays to control most of the equipment (it’s all 5v dc, pumps heaters etc). Could I use a logical Mosfet connected to one of the relays to dim the lights? Or would using the atoms3 to control the both relay and the Mosfet cause some sort of feedback loop? (Never used a Mosfet so just assuming needing a relay to perform off/on).



  • @daniejd no you can’t use a relay to dim. From your posts you should learn the basics of electronics and PWM control. A relay is only an on or off device it doesn’t do variable.



  • Sorry I wasn’t clear. I was asking about this.

    Relay > Mosfet > LED

    The relay to control the on/off
    The Mosfet to control the dimming



  • @daniejd you don’t need the relay if you have the proper mosfet control.