How to split 12V power suply to arduino and led matrix panel
No,you cannot split the voltage and expect the devices (Arduino and LED strip) to work correctly together (would lead to different ground levels beside other problems). For getting a different voltage you would need a voltage regulator. A switching &quot;buck&quot; regulator is the better choice here than a linear regulator (lile the one on the Arduino), since it is way more efficient (To get from 12V to 5V a linear voltage regulator would burn up the excessive 7V as heat).
But since both Arduino and LED strip use 5V, why not just buying a 5V power supply, which can provide enough current. Then you can connect it to the Arduino and the LED strip in parallel. No need for voltage regulation in that case.