### First Please read: https://easyeda.com/andyfierman/Welcome_to_EasyEDA-31e1288f882e49e582699b8eb7fe9b1f ### Schematic 1. Your ground (negative supply) connections are all separate. Should they not all be the same GND net? 2. How are the three MOSFETs supposed to work? Is the MCU supposed to turn them on and off and so turn the colours in the LEDSTRIP on and off (presumably using a Pulse Width Modulation (PWM) signal to control the brightness)? If yes then you have connected them wrongly. The gates should go to the MCU and the drains should go to the LEDSTRIP 3. Have you checked all the unconnected pins? What are the 3.3V pins for? 4. Place not connected `X` symbols on all unused/unconnected pins to clarify the schematic and help in Design checking (the Design button in the left hand panel). ### PCB 5. Increase trace widths especialy power. Why not place a top layer +5V copper area? 6. Add 100nF decoupling cap across Vin and GND pins on MCU. See: https://easyeda.com/andyfierman/Power_supply_decoupling_and_why_it_matters_-451e18a0d36b4f208394b2a2ff7642c9 7. Put symbols for your mounting holes in the schematic (the reason for this is explained in the link at the top of this post).

Thanks! I edited it, if you check again please. I changed up the MOSFET connection, yes. 3v3 is not needed for this project, 12V is supplied via DC jack, which is needed for the LED Strip, then it is converted to 5V and then this 5V is supplied to the MCU via the Vin pin. What trace width is considered good-enough for this kind of application? on the 5V there wouldn't be more than 500ma i think, but on the 12V side the LEDstrip could consume up to 3A. Should i use a wire instead of the tracks? Decoupling caps are a little bit new for me, i read that it'll only work if it's connected directly right before the Vin pin of the MCU so power has to go through the cap before reacing Vin. Is this correct, or it doesn't matter, and the cap just needs to be connected to the Vin and Gnd? Thanks for the help and clear-up! :)

You do not appear to have specified what the MOSFETs are. You therefore do not know if you have them in the right package and have the right pinout for the package you have placed on the PCB. You also do not know if they are suitable for being driven fully on by only a 5V gate drive from the MCU. Your 470uF cap will explode because it is rated at 10V but is run from a 12V rail. Electrolytics should be specified for at least 1.5 times their operating voltage. Please re-read and understand the importance of the checklists in: https://easyeda.com/andyfierman/Welcome_to_EasyEDA-31e1288f882e49e582699b8eb7fe9b1f For advice on trace widths for current carrying capacity and temperature rise, please search the web for: **trace width calculator online** `it'll only work if it's connected directly right before the Vin pin of the MCU so power has to go through the cap before reacing Vin` Route from the power source to the cap then to the pin on the MCU. Do the same on the ground side. If you use a copper area as a power plane for both ground and 5V then you just have to put the cap as close as possible to the pins on the chip. Find and read the chip manufacturer's datasheet and apps notes for advice on how to route the device and to apply the decoupling.

These IRFZ44N mosfets are working okay on a breadboard, so that's not a problem, but i will use a different one which is more suited for the MCU's 3v3 logic level. (don't remember the exact type right now, but will test them ofcourse) Yeah, voltage rating is also a mis-selection, i'm using 35V one. So anyway my question was about the layout of the PCB and you wrote really good points about what could be the issues, thank you very much! :)

The design flow in EasyEDA is to stay with a schematic, get the connectivity, the devices and the packages and pinouts and the BoM information correct. If you do that and clear all the Design Manager errors and warnings then your schematic will pass start into PCB without having to worry about choices and voltage rating errors. Get it right first, then it will be right first time. :)

Yeah, i'm getting the hang of it. However i have no problem with the components itself, i'm only new to pcb designing, hence i learned about copper planes and decoupling caps the other day :) Thanks again!

You also need to check what input current your 12V to 5V converter draws. If it a linear regulator then it will draw the same input current as the load (plus a small quiescent current). If it's a switch mode supply then it will draw `Iload*Vout/(Vin*efficiency)`. Check also the input and output decoupling requirements for the regulator. All this stuff is why we recommend that people read our tutorials etc. before starting a design. :)

Will check for sure! Well, if i didn't start to design something, i would never learn anything in the first place :) Of course i will only order it if i'm 100% sure it's okay :)

If you can pass all the Essential schematic and PCB checks linked to in the **Welcome to EasyEDA** project then you should be ok.