Hi I am building a project with very limited space where the board and the LEDs have to fit into a space not much larger than the board itself. I am keen to be able to connect the LEDs directly to the pin outputs of the Xiao board (with resistors of course) to make a random set of 3 LEDs to fade on and off. I won’t have room for transistors etc. What I need to know is can the board take the direct connection of the LEDs? I estimate that each LED will be approx. 20mA.
Regards
Cavan
If you connect one, it might work.
Thanks for that. What I need to know it what the maximum current draw per pin is though so I know whether I am over driving the pins.
Regards
Hi @FatherCool, In the ATSAMD21G18 datasheet I/O Pin Characteristics mentioned, I think it will help you.
Thanks, I saw before that but it gives a max of 10mA or 7mA which isn’t enough to drive a single LED. Can the Seeeduino only be used for low current signal generation?
You might need to use a MOSFET or something to drive these many led’s.
Yes I understand however I cannot fit 3x MOSFETS into the space available. I was hoping that the board could drive 1No LED per pin but it appears not. Oh well. So can I assume a max of 10mA per pin moving forward?
I think yes and what about the led specification! how much current it draws!
Yes indeed. They are 20mA specification LED’s. The LEDs however will draw what I tell it to with resistor values based on the 3.3v supply, I need more than 10mA so I think I will try to use very small transistors driven by the Xiao to switch/fade the LEDs.
