Sorry if this is a dumb question guys, but this is my first time with any Arduino/electrical work.
But I have a mkr gsm 1400 and I was wondering if there's any cons to supplying my 5v solenoid with 3.3v instead since there's no digital 5v pin outs on my board.
If you have a 5v supply you can use a transistor ( either BJT or logic-level MOSFET, depending on the current your solenoid takes) to drive it.
Solenoids tend to take quite a lot of current - is your power supply big enough? And don't forget a flywheel diode across it to protect the drive device.
Ashishgada:
since there's no digital 5v pin outs on my board.
You cannot power any solenoid directly from the digital pins on any Arduino. Usually your Arduino pin will control a transistor which actually controls the solenoid.
What solenoid? Model number, web link or current rating please.
What power supply?
How many solenoids will be turned on at the same time?
The key thing is you must always have protection from inductive spikes when switching an
inductive load - here, using DC, a simple free-wheel diode across the solenoid is usually used.
Inductive loads kick back hard and can easily fry chips / boards if you don't take this
precaution.
If you give a 5V solenoid 3.3V it will activate 2/3rds as hard, this may or may not be
acceptible to you.
The 3.3V supply you use must be able to source enough current of course...
Ashishgada:
if there's any cons to supplying my 5v solenoid with 3.3v instead since there's no digital 5v pin outs on my board.
#1 - if you have never seen any tutorials online that teaches people to drive a solenoid with a digital output pin of an arduino..... then it should be an obvious indicator that it is not meant to be done.
#2 - if a solenoid is meant to have 5V applied to it for reliable operation.... then it's probably a good idea to use 5V. The assumption is that the voltage source is able to also supply the required amount of current...........so... power supplies have power ratings.