First time designing a PCB

Hello all! I’m designing a PCB for my senior design course for our project but I don’t have all that much experiences on it. As i’m still learning i will love if i can get some opinion on if my pcb design looks good or if there’s things i can improve on or change. my project has many components such as a arduino Uno R3, AHT20, SGP40, PMS5003. Arctic P12 120mm fan, a L298N and a HC-06. Thank you!
Danny’s & Valentina-SmartAirPurifierFritzing PCB.fzz (149.2 KB)

You have some problems. The first thing to do is run DRC (Routing->Design Rules Check (DRC)) which will flag problems.

If you click on the first line, it will highlight in red the things it thinks are in error (either to close or in this case overlapping.) In this case (circled in red) the two bottom layer traces are overlapping and need to be moved. In general they should come out straight from the pin then route with 45 degree bends to the destination. In this case the two traces overlap each other and will short the pins together. I corrected this by moving the trace circled in green from the bottom layer to the top layer to avoid the other trace.

and set the grid size to 0.02in to allow the traces to be aligned straight in to the pin and have 45 degree bends.


Breadboard (and the part!) are wrong as well. You need to connect to the pads like this:


the red needs to move to the green like this

same for the other part. Despite what pcb view shows you can’t connect to the SMD pads in pcd (the part is not formatted correctly, the SMD pads should not be present in pcb!)


A couple more errors. You need a ground connection in breadboard between the Arduino and the motor driver

and to remove the connections between out1 and out2 and In4 and ENB on the motor driver (these may be shorts from the overlaps in pcb which will reflect back in to schematic and breadboard.)



Thank you peter and everyone for your advice and guidances! There was a lot of issues with the current design, i didn’t even know about the DRC! I’m going to continue working on it and show case the updates here if there’s anymore feedback i’m all ears.