I am attempting to whip up some minor PCB's to be fab'd, and would appreciate some reviews before sending them out.
It been roughly a year since I even worked in Eagle..(so definitely some ring rust)..
There are also some 'firsts' for me here.. as I have never worked with screw terminals before.. nor through holes parts before (everything I have ever done in the past has been all SMT stuff)
Summary of project.
This is really just a 'motherboard' type of PCB.. meaning that it (more or less) have some power regulation, a few passives, and some female headers for a NANO and a DFPlayer audio board to 'plug into'.
There will be screw terminals around the board to easily connect:
Main power (latching) switch
Neopixel Ring #1
Neopixel Ring #2
Similar to this Nano Screw terminal board: (but with voltage regulation and room for another audio board)
I have never used screw terminal components before..
Is the 'double' line the 'front'? (where the user would insert the wires?)
I read that the square pad is normally to the 'left' side when facing you.. and is mostly used for the V+ (but that can be used as whatever in your design)
I believe I chose the SCREWTERMINAL-3.5MM part.. instead of the 5MM variant.... what is normally used when people add these to their projects? Is there a preferred size? (and why?)
ROHM Semiconductor: BA50DD0T (Fixed, +5v/2A)
This is the chosen part for regulation... however reviewing the datasheet, I'm not sure how its supposed to be wired up? I 'think' the diagram I am supposed to follow only has a 22uF cap on the output? (thats it)..
I added another 22uF cap on the INPUT as well...... bad move? Overkill? Not needed? (Remove it?)
MAIN POWER TERMINAL:
One of the terminals is intended for a latching switch to be connected to it.. so it can toggle the main power the project.
I'm not sure if in the schematic that is the correct way to do this? I was really struggling on how to join the nets/lines in the schematic.. but not sure if that maters as long as its routed correctly in the board design??
You'll see in the board file I added some poly fills for ground planes.. but moved/chopped it away form the BATTERY TERMINAL... so the MAIN POWER TERMINAL will break/connect GROUND. Is that the proper way to add in a 'main power' switch? On the GND line? Or should it go on the VIN line? (or doesnt that matter?)
THROUGH HOLE PARTS:
I have never really used through hole parts.,. so when picking a capacitor... how do I know I have the right 'size' (footprint?) I mean the schematic symbol is fine/universal... but the board footprint/symbol is what I'm concerned about.
I used a NANO component for its footprint... but it also seems to have the ISP header broken out in the middle of the board.
Not great.. but that wont really be connected to anything in the end.. since the nano will be plugged into 2 female header rows..
Is this fine? Or should I replace with 2 female header rows?
I also added some extra pads to be able to tap some power sources (+3.3v, +5v, VIN..etc)
As well as another set of pads for battery connection. (noted on the schematic)
In order to NOT have an GOUND connection when the switch is off.. I made some odd shaped poly fill ground planes.. (I have only ever made full size ground planes before.. so not sure if this logic is sound.. of if this practice/approach is no good?)
I'm hoping there isnt too much wrong.. as I'd like to get these sent out today.. and start the process.
Schematic: (right click and view image to see it at full size)
And EAGLE file(s): (.sch & .brd) for review in real-time:
Thanks for the eyes & the time guys!