Basically, I want to control 4 motors with propellers on a single Arduino, control each motor’s speed independantly (making some basic quad copter project).
You can build it, and you can make the motors spin, but I guarantee you can’t ‘fly’ it in any controlled manner. You will have built a Flying Blender which will zoom off in any random direction.
First, all multicopters have flight controllers with solid state gyro type sensors that keep track of which way the vehicle is pointed, which way the pilot asks the vehicle to move, and then adjusts the motor RPMs to make the vehicle go in that direction. No -human- can control 3 or 4 motors fast and precisely enough to manage vehicle motion in 3 dimensions.
Best, openpilot.org Revolution
Low budget but works (and often out of stock and hard to find -because- it’s cheap): hobbyking.com KK2
Next, even with a flight controller, without a LOT more advice you’ll never be able to pick out the right -match- of weight, power, RPM, battery voltage and mAh, and most importantly prop diameter and pitch. Typical results might be…
Motors spin but it never lifts off. Wrong prop, or purely too heavy for the motors.
Motors spin and it lifts off but lasts only 20 seconds, because the batteries ran down. Which results in loss of power to the flight controller, crash and destruction.
Motors spin and it flies nice for 30 seconds, a motor overheats and burns out in flight. Again the result is crash and destruction.
It flies, and 2 minutes later the battery overheats and catches fire. Crash, destruction, plus fire.
An electric powered flight system is a -designed- -package- not just random parts put together.
Yes you can plug in the gyros, but you’ll spend months of not years writing the code, which is why I mentioned Arducopter. (Arducopter isn’t an Arduino with plugged in gyros, it has them already built into the main board.)
See rcgroups.com and start reading… Find out how to design a copter and you’ll have a much better chance of success. Oh BTW -you- can’t do the first flights yourself either. You’ll need to find an experienced pilot to try it and find out if it’s even -potentially- flyable.
There are standard parts kits that have everything already designed as a package. If you really need to do a lot more DIY, which is of course half the fun, you’re much better off finding a known proven standard design that already tells you all the parts you need that work right together. Experimental design is only for the very experienced.