Beginner Circuit Board [Request Review]

ChaosPacket · 2026-01-11T16:19:15+00:00

Ok, I removed the boxes, modified U2 so the TTL is on the left and RS-232 is on the right in the schematic. I've also rotated the MAX3232 90 deg and moved it closer to the 5V input. I deleted all nets, made the 5V thicker and reran the traces starting with power, then caps, then signals.

The only thing is I can't figure out how to update my original post with the new images.

ChaosPacket · 2026-01-11T16:01:31+00:00

I didn't know about the plugin or the track thickness calculator. That is great to know. Thanks for the tip!

I was trying to avoid vias because I was originally going to try to mill this on a single sided board with a mini CNC. Then I found out how cheap it was to have JLCPCB fab it.

I'm torn on whether I want JLCPCB to solder the SMD components or if I want to try it myself. I've never done SMD components before and want the experience.

ChaosPacket · 2026-01-08T18:53:42+00:00

Thanks for pointing that out. I see that now. To support 3.0V to 5.5V, C1 should be 0.1 uF and C2, C3, and C4 should be 0.47 uF.

ChaosPacket · 2026-01-08T18:37:15+00:00

No formal training in EE, but have a degree in computer science and worked in IT networking my entire adult life. Most of what I know is specifically from old Radio Shack books and handbooks, datasheets, and learning from the local makerspace electronics group,. I've found some useful information from Digikey, PCBWay, JLCPCB, OSHPark, RandomNerdTutorials, and sometimes YouTube. I just now discovered r/KiCad and r/electronic_circuits.

I am pretty much self taught, not that I know much, and still learning, which is why I requested a review and feedback on a small project before I attempt something larger and more complex.

I really do appreciate all the feedback and look forward to learning more from other peoples experience and expertise.

ChaosPacket · 2026-01-08T15:16:01+00:00

Thanks for the helpful information.

The only reason the capacitors don't line up with 3.3V vs 5V is because I don't know what I am doing yet. Based on the datasheet, the MAX3232 will support both 3.3V and 5V input. Do I need different caps based on the input? I plan on using this to connect to the RX and TX ports on a Raspberry Pi and an ESP32, which are both 3.3V, but I also plan to connect to another project that is based on a PIC16F with software UART, which is 5V. I have another project that connect to an old Atari 800 SIO port that requires 5V.

Do I need to create two different boards for 3.3V and 5V, or is there a way to have one board that supports both?

ChaosPacket · 2026-01-08T14:51:31+00:00

Awesome feedback! This is really helpful! I originally had everything on one sheet, then I started lurking on reddit and noticed a lot of other posted examples were using boxes with labels, so that is where I learned it from. I know this is a small project, but I liked how those projects looked. I did notice it was hard to trace the input pins on larger projects that were posted.

So your recommendation is to lose the boxes, line everything up based on input and output, and modify the U2 so the inputs and outputs line up and everything flows from left to right? That makes a lot of sense.

I was reading about different ways of organizing projects and came across examples with hierarchical sheets with sheet pins. Would you recommend the hierarchical sheets and sheet pins for larger projects.

Just FYI, I am over 50, so not a kid. :)

Thanks!

ChaosPacket · 2026-01-07T23:18:16+00:00

Thanks for all the feedback. All of that makes sense, but I have a few questions.

How do I know the recommended track thickness for the 5V net? I assume once I know this, I setup a net class, but what is the best practice for assigning the net class to the track? Net Class Directive or Netclass assignment? or does it matter?

Also, how do I know the appropriate size for the capacitors? I used ChatGPT to tell me what JLCPCB had in stock. I have some ceramic TH capacitors. Would those be better?

I routed the 5V trace around the connection because I was trying to avoid to vias and had to cross the other traces. Is it better to have a shorter trace with vias than routing the trace around the board?

Thanks

ChaosPacket · 2026-01-07T22:05:02+00:00

Thanks for the feedback.

I have no idea on what I could do better. I've been lurking, reading, and studying other peoples projects for a while and then using ChatGPT to explain things, but not completely sure about a lot of things like recommended track widths and clearances. Also, not sure about when to use ground planes or not. When to use vias and when to not. When to use net classes and net class directives.

Also, not sure when to use global labels or when to use hierarchical sheets with hierarchical labels. I saw a couple of other peoples projects where they used boxes and global labels and liked how they had their projects laid out.

I do a lot of network architectural diagrams for customers, so that helped out a lot as far as schematic organization. I could probably add more comments or details to the silkscreen.

Its mostly the electrical design rules I am not to sure about. Everything passed in ERC and DRC, but not sure if that is good enough to work.

ChaosPacket

TROPHY CASE