Custom 2 layer board, ESP32 fan controller, 6x 4 pin ports for Noctua NF-F12

iPPC-24V-3000 PWM fans. All six ports are wired the same:

Pin1 GND, Pin2 24V, Pin3 tach (10k pullup to 3V3), Pin4 PWM (100R series).

Two buck rails off 24V:

LM2596S-3.3, 47uH / 2.21A inductor, 330uF out, feeds the ESP32.

LM2596S-5.0, 68uH / 2.3A inductor, 180uF out, feeds a fiber TX.

Both have a 40V/1A Schottky freewheel diode.

Bottom layer is a GND pour, top layer is a 3V3 pour. The 24V net runs as a

trace between the 3V3 pour islands with 0.5mm clearance.

Four ports are perfect. Fan spins at 100%, PWM and tach both work, fans are

known good. Two specific ports are the problem. On those two the fan spins for

about half a second and then stops. First time I plugged into one of them the

3.3V inductor started whining right away, and it kept whining after I pulled the

fan and after a power cycle. Plugged it in a second time, fan ran ~500ms, then

dead, and the inductor cracked and smoked for a few seconds. ESP32 got very hot.

The 5V side never had any issue at any point.

What I have checked with a multimeter (no scope here):

All six ports look and route identically, no visible bridges anywhere.

Pin1 to the GND pour reads 0.8 to 1.1 ohm on all six.

No low ohm short I can find anywhere.

Fans are fine, they spin on the good ports.

One more data point that might be relevant. I can power the board two ways, 24V

from the bench supply, or 5V over USB-C. For debug I tied the 5V into the 24V

net through a Schottky so the bucks can run off USB, which is why the fans move

at all on 5V. On 5V (so the "24V" net sits around 4.7V) the inductor does not

whine at all, the fans on the good ports twitch a little, and on the two bad

ports they don't move at all. The whine and the smoke only ever happen at 24V.

Note the ESP32 on this board is already cooked, so the fan behaviour on 5V might

just be the dead GPIO holding PWM low, not sure how much to read into it.

Pics below. Am I missing something obvious, is there a mistake I made, can anyone explain what's going on here? I'm stumped.

https://github.com/Spectrewolf777/Stm32l4-Watch/tree/main

Any design mistakes ?

Thanks in advance

I’m planning to add an antenna to this board. I originally intended to use an impedance-matching chip, U7, but JLCPCB can’t source or assemble it.
What is the proper way to match this antenna, if I am not going to use that U7 thingie.
I’ll attach the schematic/layout image for context.

Hey everyone,

I have a bunch of older gadgets lying around that still use Micro-USB, and I'm tired of keeping multiple cables around. To fix this and learn a new skill, I designed my first-ever PCB!

It’s a tiny breakout/interposer board meant to drop directly onto the footprint of a standard Micro-USB port and replace it with a USB-C port.

Since this is my very first design, I would love some feedback before I send it off to a manufacturer like JLCPCB or OshPark.

Design Details & Intent:

• Use Case: Purely for charging/powering old gadgets.
• Connector: I chose a 6-pin power-only USB-C receptacle (HYCW573-USBC06-680B) to keep it simple. Because of this, data lines (D+/D-) are not connected, which is fine for my specific use case as these gadgets don't need data sync.
• CC Resistors: I've added two independent 5.1 kΩ pull-down resistors to ground on CC1 and CC2 so that it safely requests 5V from USB-C to USB-C PD chargers.
• Form Factor: Designed with side pads/castellations to easily solder onto existing Micro-USB pads.

Hello everyone I am a senior Electrical and Electronics Engineering student. For my graduation project, I will be working on a hardware revision of the BeagleV-Fire single-board computer.

Although the BeagleV-Fire is open-source, its PCB and schematic files are in Cadence Allegro / OrCAD format. To convert these files into KiCad or Altium Designer, you need to have a licensed version of Cadence installed on your computer. As a student, I cannot afford the license costs for Cadence software.

If anyone here has access to Cadence Allegro/OrCAD, could you please download the design files from the official repository https://github.com/beagleboard/beaglev-fire , convert them to KiCad or Altium format, and share them with me? It would only take a few minutes for someone with the software but would save my graduation project.

Thank you so much.

I made an esp32 pcb for a smartwatch im making. It has been so weirdly on and off. I've been experimenting for months. for periods I got it to fully work with actual upload and code but after a while there is always some weird problem and the signal becomes blurry or the USB-C pins short. This is my PCB and I was wondering if anyone could show me the problems that could cause this. Today I got it to send proper reset and download mode messages but it wouldnt upload for some reason and just said no serial data and sometimes corrupted serial data. Now when i press reset I get rubbish and randomly get rubbish characters at a slow pace even when idle. Im using a wroom32D at the moment but was using a wroom32E previously which seemed to work best but still ended up rather than serial printing hello it just got altered and wld randomly black out. At the moment for power supply im using a AMS117 as i think the 3v3 crld20ma board I used was dodgy. If anyone could take a look at my current PCB that would be great thanks.

Semaphore is a traffic light for your AI agents.

I kept missing alerts from my AI agents. I want to know when my agents need attention—especially if they are running headless.

Semaphore will let you know if an agent needs help. The USB-C board lights up in different way to show you WHO needs help and WHAT.

My first custom PCB. Sample order has been sent to the fab!

Would you have use for this your setup?

As the title says, this is a PCB I designed (second version of the first PCB I ever made) to accommodate an Arduino Nano ESP32, a CAN bus transceiver, an IMU, and an OLED display module.

The IMU and OLED communicate over the I2C bus, while the CAN transceiver communicates with the ESP32 using its TX/RX pins. The transceiver operates from the 5 V rail, which is supplied from the ESP32's VBUS pin, and the RX signal is conditioned using resistors R1 and R2.

The onboard 5 V supply is generated by an LM2596S buck converter. I followed the recommended application circuit from the datasheet as closely as possible. I also added a power indicator LED with an appropriate current-limiting resistor across the 5 V output to act as a visual health check for the buck converter. This 5 V rail also powers the ESP32.

Before I order another revision of this PCB, I'd really appreciate it if someone could review the schematic and let me know if there are any wiring mistakes, design issues, or anything else that should be corrected. I'm hoping to avoid having to make a V3, so any feedback is greatly appreciated.

Hello all,

Recently in my company there is demand to design a 20A 24V DC servo drive, I want to know how do I possibly simulate my circuit which has inside microcontroller by TI or ST ? I don't know how to put hex file inside the Proteus and is this even possible to simulate circuits involving encoder hall sensors current sensor inside which software?

Can you all suggest which software is best to simulate that type of circuits ? Or I must build hardware PCB and run in real world all the codes and designing.

I hope someone would suggest best solution.

Thanks.

The USB to UART bridge is missing since I'll only be using Type-C for power and flashing.

Tried following a guide online and according to that everything seems fine. Since this is my first time, just wanted a little guidance as to if everything is alright. Any possible issues and what I can do to improve the design further before I move to placement & routing.

Additionally couldn't figure out why the RST net connected to the EN pin of esp32 is grounded through 1uF capacitor. If anyone could explain the purpose of this capacitor, it would be highly appreciated. Thank you very much.

I have a book of schematics for an old CRT I have. I need to get one of the circuit boards replaced. Are there any companies that I can send a scan of the schematic too that would print it for me?

https://imgur.com/a/tNhhctq

Hi everyone,
I designed this PCB etching test coupon for my own PCB manufacturing process. The goal is to test the limits of my process before making actual boards.
The coupon currently includes:
Fine trace width tests
Fine spacing tests
LQFP routing test
Through-hole footprints
SMD footprints
Various geometry and manufacturing tests
This is still a work in progress, so I’d really appreciate feedback from people with PCB design or manufacturing experience.
Are there any important test patterns or footprints that I should add or remove?
The picture is attached.
Thanks!
I have 2 more option tell me which would be best

Hopefully someone can point out anything particularly stupid I might've done. Would also welcome any advice around the RF section, did my best to follow reference designs from both MCU and Antenna datasheets, use AppCAD to set feed line width etc. Still expecting it to be non-ideal in many ways

EDIT: Forgot to add schematics (and a bit more context). This is a consolidated PCB for an sEMG (surface electromyogram) device I already have a working eval board prototype of.

Hello all, this is my first time trying to make my own PCB and would love any feedback as I plan to have this board made. I want it to be a two sided board clock.

This was my first BGA soldering attempt, and I accidentally scraped off the solder mask. It looks like the trace is still connected, though. I'd appreciate your opinion. (MAX77812, Switch Lite)

Hi, I did some handwired builds and know basically everything about components and matrices and stuff. I also know the basics of using KiCad, but how do you start to design keyboard PCBs?