hi all I am hoping someone has a moment to look at the pcb design for me I just want a second set of eyes to look at it before I start make it as this is the jurst board I have made so not sure if the design will work or not it is for an arduion nano if that matters I am attaching the schematic and the pcb with labels all the vias are for wires as I ended up in a few places I couldn't get back to the arduino pins with traces


Thanks,
Yonu

 

Your traces are a bit haphazard and you have a 90 degree bend which is generally discouraged unless absolutely unavoidable (it causes current crowding on the inside corner). If there's a possibility that you'll be reworking the board, enlarging the pads will make that easier. If you didn't mount the resistors vertically, you could avoid the jumpers; you appear to have plenty of space. I find it more aesthetically pleasing to layout components in some sort of grid.

 

Yeah I know they are a little haphazard.

I originally started with the resistors laying flat but I could not seam to get everything on the board. Which is why I switched to vertical resistors and diodes. what is the trick to working with a PCB this size and getting everything in?

 

what is the trick to working with a PCB this size and getting everything in?

Thoughtful component placement, well drawn schematics, experience, practice, ...

 

makes since I am used to working from scratch on perf board I just figured for something this small a printed board would be easier back the the drawing board I suppose.

Thanks,
Yonu

 

Here's a 1.5"x2.0" board I did about 10 years ago

 

all I can say is wow that looks good

 

all I can say is wow that looks good

Thanks. Note that I violated the rule about 90 degree bends at the bottom of the board. It was a conscious decision because using 45's would have removed clearance to the nearby pin. Since I etch my own boards, I try to reduce the "hard" areas. The trace in question only carries a couple mA, so current crowding isn't an issue.

 

I noticed that but I wasn't sure if that had been on purpose or not


if you would have a look at this I decided to start over and was shocked how quick it came out compared to the last one the only problem I have is R4 which one side should be going to ground but I have got it land locked


Thanks,
Yonu

 

You need a better PCB software.It could really change the tables.

 

I will play with some other programs but let me ask you from the jpg I just uploaded can you see any way with a single layer board to get R4 to ground without using a single wire?

Thanks,
Yonu

 

from the jpg I just uploaded can you see any way with a single layer board to get R4 to ground without using a single wire?

Move R4 next to R10, straddle the trace from R10 going east, and pick up ground from C4.

 

I decided to start over and was shocked how quick it came out compared to the last one the only problem I have is R4 which one side should be going to ground but I have got it land locked

If you label the pins on your board, I'll give the layout a try when I have some time.

In the meantime, you can make your board more aesthetically pleasing if you keep the components on a 0.1" grid and line them up. For example, R1, R3, R5, and D1 can be lined up.

 

Here is an example of what Dennis is talking about.

 

I will play with some other programs

What program are you using? Does it show you a ratsnest (fly wires) when you're placing components?

On your layout you have the two transistors about as far away from each other as possible; but, on the schematic, they're close. That's what I meant by topological (well drawn) schematics. A neat schematic should make it easier to create a compact PCB layout.

 

KiCad is free program for PCB design. Take a look at it.

 

I am using fritzing as it is what I have used for perfboard layouts in the past. yes it shows ratsnest wires but I don't have the schematic entered in the program as I am working from the one provided with the code. The only reason I have the trasnsisters far apart was to make it easier to get all the traces in place

 

oh and I just saw the post about moving R4 I don't know why I didn't think about placing the resistor over the trace.

Thanks,
Yonu

 

oh and I just saw the post about moving R4 I don't know why I didn't think about placing the resistor over the trace.

Two of the I/O's are missing (I labeled the 4 you connected):

What are the dimensions of the board? Are the pins along the left/right edges 0.1" spacing? Are you trying to do a single sided board?

 

ok the pins on the right and left are 0.1" yes I am trying for single sided. The board is going to be 0.73" x 1.70" the same size as an arduino nano.

I assume the 2 missing IOs you refer to are the cec_line and cec_gnd they ae the 2 marked vias as right not they are gonna be wires in the board that goto the 2 wires on the hdmi port.

Thanks,
Yonu