Rocket controller board review - Page 1
Forum section: electronics / beginners

author: maxall4
author_rank: Newbie
timestamp: May 20, 2021, 10:20:53 pm
content: I was wondering how bad my board design is. Does anybody have any tips?

author: ataradov
author_rank: Super Contributor
timestamp: May 20, 2021, 10:42:42 pm
content: It depends. It would probably work, but it is a very typical beginner board. There is no reason to have traces this thin on a board this large. There are too many unnecessary layer changes.Aesthetically it looks pretty bad. Electrically - it is fine.

author: deskpro256
author_rank: Contributor
timestamp: May 24, 2021, 01:45:16 pm
content: Hello, I'll also give my 2 cents on the matter.First of all, welcome!We all start somewhere and I still have some of my first PCB's home to see improvement over the years.Dave recently did a PCB layout review for another forum user:Watch it and try to see what you can do to your board.Without seeing the schematic, it's actually harder to know if it will be OK or not. Electrically it may be connected alright, but there might be a problem with the circuit itself we can't know what are all the components without a schematic.This board layout screams EasyEDA autorouter, which the developers themselves have said to not use, especially as a beginner. The autorouter doesn't know the circuit, it just connects the dots.I see posts on EasyEDA forum about autorouted board problems every day, people just think it will fox all their problems, but usually they just create more problems.Please unroute the board and do the routing yourself. It's not that complicated, you are just connecting modules. If you'd just solder them on a perf board with wires, that would be better than what the autorouter didThink about the PCB itself, are there specific size constraints to it? Does it have to fit some enclosure, shape? How will you mount the PCB to your enclosure? Screws? Press fit? Duct tape?Before doing the layout again, please take a look at your component placement. Are there components that need to be close to other components/modules/connectors? If yes, then move them, rotate them so the ratlines are as straight and crossing the least amount of other ratlines as possible.What is the voltage for the input DC jack?Is U2 a linear voltqage regulator like a 7805?Decoupling capacitors for the input and output?Are U2 and U3 going to be mounted like that on the PCB, do they need to be screwed to the PCB(watch out for the GND trace under it) or will they be vertically mounted? Are they going to heat up? Heatsinks?Shouldn't the fuse go before U2 or at least also before U2_Pin_1 if what is connected to J1 could cause a problem?Also, the huge traces from DC1 to U2_Pin1 & Pin2 are almost touching. Looks like they are ~70mil tracks, does the project really need them?Why did you put the flash memory chip on the bottom while everything else is on the top? You have plenty of space already and even more if you move things around.What is J1?What is the 2 pin connector with the "+" next to it?Through hole resistors? You have an SMD fuse and U5 is also an SMD device, an 0805 resistor is plenty small and large to easily solder, think about those too!Can the servo motor traces handle the current required?You can look up some trace width calculators. (20 mil could be OK for 1A)Don't let the autorouted do the GND and PWR traces because it will screw up the whole board. Get the signals first, then the power and then a GND plane on top and bottom, then connecting the possibly unconnected GND connections with vias.Also how will the Teensy get programmed? Is there a USB connector on the board? Is it accessible as it is right now? Are there programming pins necessary?If you are serious about PCB designing, do some more research about good practices. The skill will come with time and practice!You can also watch a few videos like this:Hopefully this doesn't discourage you from continuing the project!Keep doing it and you'll see improvements in no time!