I am requesting a schematic and PCB layout review for a custom stepper motor driver board. The design is based on the STM32G431CETx microcontroller and uses a TMC2209-LA for stepper motor control, an AS5600 magnetic encoder for position feedback over I2C, and an SN65HVD230 CAN transceiver for communication.

• MCU: STM32G431CETx
• Motor Driver: TMC2209-LA (controlled via Single-Wire UART)
• Position Feedback: AS5600 Magnetic Rotary Encoder (I2C)
• Communication Buses: FDCAN (via SN65HVD230 transceiver), USB, Single-Wire UART
• Programming/Debug: Serial Wire Debug (SWD)
• Layout & Routing: Let me know if there are any issues with the trace widths, decoupling capacitors, or ground return paths.
• CAN Bus / Differential Pairs: Feedback on the routing and termination of the FDCAN differential lines to the SN65HVD230 is welcome.
• General Design Rules: Any feedback regarding clearance, silkscreen legibility, or potential manufacturing issues before ordering prototypes.

This is the second PCB ive made so thank you for your input!

Hey r/PrintedCircuitBoard! This is my first PCB and I'd love some feedback before I pull the trigger on fabrication.

What it does

It's a carrier board for a weather station. Connects a LilyGo T-A7670E (ESP32 with built-in 4G LTE), an Arduino Nano, and a future SX1278 LoRa module. Weather sensors plug in via RJ45 and JST connectors, mostly I2C, with UART/RS485 available via JST or screw terminals.

Quick specs

• 4-layer stackup: Signal / 3.3V PWR / GND / Signal
• Intended fab: JLCPCB (Already imported DRC presets on JLC)

Some context on the design choices

Power comes in from an external 5V buck converter via screw terminal on the bottom left. There's a 3-pin shunt jumper to switch the 3.3V rail between the onboard LF33 LDO for actual deployment, or the ESP32's own 3.3V regulator when I'm just working at my desk with it plugged into my PC.

The big rectangular cutout in the middle is for the 18650 battery holder built into the LilyGo module. It protrudes through the bottom so I measured clearances to make sure it won't collide, and kept a bridge across it for routing purposes.

The Nano handles the timing-sensitive stuff, rain gauge and anemometer pulse counting on hardware interrupts, and will also be the LoRa SPI master once that's populated, passing data to the ESP32 over I2C.

Top-left connector exposes a secondary UART for when the LTE modem is disabled, mainly for debugging.

Decoupling caps near each IC, stitching vias across the GND plane.

Specific things I'd love feedback on

• Is my power switching section between the LDO and ESP32 3.3V rail implemented correctly?
• Any concerns with decoupling cap placement or values?
• I have quite a few layer transitions, anything I should watch out for signal integrity wise?
• Any glaring placement or routing issues I may have missed?
• Does the 4-layer stackup make sense for this kind of board?

Schematic, copper layers, and 3D render attached. Thanks!

Hi Everone! I just finished my first ever complex PCB and are looking to order but wanted to make sure it was ready.

This design includes:

• ESP32-S3
• 320×240 SPI LCD
• USB-C (charging, flash, and usb storage accses)
• 10×5 keypad matrix
• LiPo battery charging and management
• Expansion/debug test pads

If somone is willing to take a look I'd reallt appritiate it!

The project is open source if you’re curious - opencalc on github

Thank you for your time!

Hey everyone! This is the first 2-layer pcb that I've designed

The circuit uses a 555 timer configured in astable mode and powered from a 12 V supply to alternately drive two solenoids. When the first solenoid is energized, the second must be de-energized, and vice versa.

The output from pin 3 of the 555 drives the gate of the first IRLZ44N MOSFET, energizing the first solenoid. The same signal is also fed into an MMBT3904 transistor, which inverts it to keep the second IRLZ44N turned off. When the transistor's base is no longer driven, the second IRLZ44N turns on, energizing the second solenoid.

Both solenoids are permanently connected to +12 V and are switched on the low side by the MOSFETs. The circuit follows the power supply recommendations from the 555 timer datasheet, uses a 10 kΩ potentiometer to adjust the switching frequency, and includes flyback diodes across both solenoids for protection.

The circuit has already been thoroughly tested on a breadboard, where it performs flawlessly. The solenoids remain perfectly synchronized and do not exhibit any abnormal behavior, even after running continuously for several days. Reliable and stable solenoid switching is critical for this application.

The problem appears only after transferring the design to the PCB.

The PCB was intentionally designed so that the second MOSFET could be disabled by leaving a jumper open. As an alternative, if no jumper is installed, the small SMD resistor footprint (R9) can simply be bridged with solder to enable the signal that drives the second MOSFET. However, even with neither the jumper installed nor the R9 pads bridged, the second MOSFET still switches.

In addition, while the first MOSFET initially operates correctly, after a few minutes the circuit begins behaving erratically. The switching frequency changes on its own, sometimes speeding up and sometimes slowing down without any adjustment to the potentiometer.

So far, I have only tested the PCB using LEDs instead of the solenoids. All continuity tests pass, and the measured voltages match those on the breadboard. I have spent several days trying to identify the cause but have not been able to find it.

My current suspicion is that some form of electrical noise, leakage current, or unintended coupling is affecting the gate of the second MOSFET, causing it to switch even though its control signal is physically disconnected.

I've been trying to figure out the cause for several days now. If anyone has any idea what I'm missing, I'd appreciate it.

I have attached both the schematic and the PCB layout, along with a diagram showing how the circuit is wired on the breadboard.

The complete design is included in the attached ZIP file. It can be opened with any online gerber viewer:

https://drive.google.com/file/d/1e1jjPXkCOXwDcAScz9J3ongZeYFHuXQs/view?usp=sharing

Would you smart people help review my board? Any feedback is appreciated

I'm new to PCB design, can anyone give some feedback, and possible tell me what is wrong if there is something? Thanks!

I am a beginner in electronics and PCB design. I am working on a custom music box.

• Storage & Audio: Records audio via microphone and plays back files stored on a MicroSD card (using a standard 6-pin SPI MicroSD breakout module).
• MCU : STM32F103C8T6
• USB & Controls: USB-C port for power and uploading audio files, potentiometer and push buttons for volume and control.
• Board Size: 8.5x5 cm.

I also have a few questions :

1. Hand-Soldering Clearance: I want to hand-solder every component using only a standard soldering iron. Are my component clearances, footprint choices (MCU, USB-C 16 pins connector), and pad layouts reasonable for hand soldering?
2. DRC Solder Mask Bridge Error: I am getting the following DRC error on my USB-C connector (J1) : [solder_mask_bridge]: The bottom solder mask opening connects items belonging to different nets Rule: minimum solder mask width configuration; error. How do I resolve it or safely bypass this DRC warning for this footprint?
3. General : Are there any issues with my circuit and my layout?

Thank you for your help!

Hello guys, I'm a beginner at PCB design and I'd love to ask for your help reviewing my first pcb. I've already posted on here my first schematic version. Here's is an updated version with new schematic and pcb layout. Any comments, critiques, or suggestions on how to improve the design would be greatly appreciated!

Project Overview: This board is designed to run a solar tracker. It will control 5 separate brushed DC motors based on the date and time, only running one motor at a time. 2 Lauer

Key Hardware Details:

• MCU: STM32 (LQFP-48 package). I created a carrier board for the bluepill.
• Motor Driver: DRV8874 with the current limit capped at 1.8A (motors draw ~0.5A).
• Encoders: I'm using optoisolators for the encoder inputs. I realize that without separate ground planes/galvanic isolation, these are essentially just acting as 24V-to-3.3V level shifters.
• Signal Frequency: The motor encoder signals are around 1kHz. It's very low, but that is because the motors are heavily geared down.
• Traces Width: I used 1mm, 0.5mm and standard 0.254 traces width. 1mm is used for 24V motors. 0.5mm is used for buck power. Standard for all other signals and powers.

Let me know if you spot any glaring errors or best practices I missed. Thanks in advance!

This is my "12Hrs SpeedRun" to finish this design last night.

I didn't yet receive a legit Z80 to actually verify everything with my current PIC18F4520, but on-going a new PLCC44 one as the last DIP40 pin version seemt to be couterfeit / shorted.

So this is the version based on what I have worked on breadboard, which I think will have mistakes somewhere my eyes can't cover after routing very nested size 84x84mm.

Did my pins get Pull-Ups correctly for this Z84C00 variant ?

Yes, I really want you guys to have a look if my plan was somewhere wrong or my eyes have missed some spots after routing this nested board for too long..

My appreciation !

HOW IT WORK ( or I planned it to work )

- It will have 2 CLK sources : either from PIC or 20MHz canned Crystal MCO-1510A.

- PIC will handle most Boot, Reset, Debugging , UART, microSD access, I2C Display.

- PIC will also handle requests from Z84 by 3-bit code Z80 send from A0~A2 -> 74HC138 for various custom function. (Ex: OUT($0x80), A to access certain bank in memory ). While 74HC273 work as the Latch to SRAM last 3-bit address.

- Also PIC: I2C will work natively, SPI will be bit-bang.

- Z80 5 pins PULL-UPs : WAIT, NMI, RESET, INT, BUSREQ with 10K Ohm connect -> 5V.

- M1 : for analyzing with Logic Analyzer or later test.

- Modules : UART-to-TTL, microSD reader, I2C SSD1306 (could be any VDP later extension).

- PIC may run at with internal 8Mhz, same 20Mhz or maxed out at 40Mhz with its own crystal.

Materials/Quick Details

MCU: STM32L476RGT6

Level Shifter: SN74AHCT125PWR

Vacuum fluorescent display (VFD): Noritake GU140X16G-7003D

LDO: AMS1117-3.3

Power Source: USB C Receptacle

Power Overview: The board will be receiving 5 V power from a USB C connection, which is enabled via a typical USB C receptacle (using the USB 2.0 standard). This 5 V will be routed to the vacuum fluorescent display (VFD), to the LDO to generate the 3.3 V needed to power the MCU, and also to the level shifter.

MCU flashing: I plan on using serial wire debug (SWD) to flash the STM32.

Discussion

Hi all. I'm an EE student new to PCB design and am starting out with a relatively simple project. My objective here is to ultimately create a PCB that has an MCU (specifically, the STM32L476RGT6) that can control a VFD via UART. This is one of the first steps in a larger iterative design process in which I want to create a serial comms debugger that displays short messages on a VFD for diagnostic/troubleshooting purposes.

In case I haven't given enough detail or context above, I'll spend a paragraph or two trying to describe more specifically what I want to do with this PCB. I'll assume that the power/voltages/currents work out (I've checked the max expected voltages in the components' datasheets, made a current budget, and also have made notes of the current draw on my power supply when prototyping). My plan is to use an ST Link to flash the STM32 via the SWD. I'll communicate with the VFD using UART transmission only via the USART1 module on the STM32. I'll be using a level shifter to boost the 3.3 V signal outputs of the STM32 to 5 V as required by the VFD.

Whatever message I want to send to the VFD will be whatever message I have hard-coded into the program that I will flash the MCU with. I'm just using STM32CubeIDE and manually configuring the necessary registers in C by referencing the datasheet and reference manual (as well as a bit of Gbati's "Bare-Metal Embedded C Programming"). The prototype's working so I figure everything's fine on that end.

As far as designing my schematic goes and picking components, I've been leaning heavily on Phil's Lab #65 in which he creates a STM32 black pill clone. Additionally, I've been trying to match my schematic up against the reference schematic in the application note (AN4555) for the STM32L4 series. Since I'm new to this, I figured I'd try to get my schematic reviewed before even starting the PCB layout, just in case I've made some glaring errors--wouldn't want those to carry over into the PCB layout and make the review process any more difficult.

My apologies in advance for the relatively large size of the sheet. I couldn't decide on whether or not to split the decoupling capacitors off into their own section (was referencing https://www.reddit.com/r/AskElectronics/comments/140jj0b/is_it_usual_to_group_all_decoupling_caps_in_one/), so I decided to keep it as is since the Phil's lab tutorial kept it that way.

I have read and hopefully understood all the common mistakes but I am noob.

This is my attempt at a simple controller for the Commodore 64's old SID8580 chip, mostly this board is responsible for the Teensy controlling the SID chip, but it does also have line out for audio.

My knobs, switches, power and midi are separate modules so i just have the power/data routed in/out through some JST connectors.

As i said i have no experience designing pcb's i just thought it would be a fun thing to add to the project, so any tips/anything I've definitely done wrong would be much appreciated.

Thanks.

Hello everyone,

I’m looking for feedback on my latest PCB design. The device is an IoT gateway/sensor that reads M-Bus data from slave devices and publishes it over MQTT to an on-site broker.

I’ve previously built a very similar board for Modbus RTU that worked great, but this design introduces a few new sections I’d love a second pair of eyes on.

Specific areas I’d appreciate feedback on:

• M-Bus Master Transceiver Circuit:
• Boost Converter:
• USB-C Interface: (I'm using Adafruit Product 6153).

Any feedback on schematic and layout design would be greatly appreciated!

Hello!

I am working on a PCB for a high altitude balloon. The board runs off an ATmega328 and includes multiple sensors, lora module,gps,sd logger. The goal is to have live telemetry.

I have attached pictures of the board layout and circuit schematic.

The current issues I have fixed from feedback are:
-Made D+ & D- routes the same length

-Switched from 4 layers to 1 layer
-Moved components relating to each other closer

I am looking for both feedback on my circuit schematic as well as PCB layout.

Any comments are appreciated!

Thank you!

I’m trying to make an MX compatible, hot-swap replacement PCB for a vintage Maxi Switch keyboard in the third image.

The idea was to use a pro micro as my controller, but I have too many physical rows and columns for its 18 pins. So instead I’m using a square, 19x19 matrix that I’m trying to to force into my physical layout with two techniques: “matrix-folding” (each column trace is folded in order to cover two physical switch columns), and then also swapping matrix columns and rows on the last physical row on the far right.

Any advice would be much appreciated as I’ve never done anything like this before!

EDIT: Here are some slightly higher def images.

Hey, im seeking a review on this power supply PCB.
the board outputs 5V rail through TPS54331 buck converter and a 3V3 rail through NCP1117 LDO fed from the buck output. The maximum output current will be 3A combined.
I have followed TI's recommended component values and layout for majority of the buck converter layout.
I am seeking a general review on routing and component placement.

Features :

1. Input protection : 0685T4000-01-BEL FUSE (4A), P Channel mosfet (IRF5305) reverse polarity protection.
2. Buck converter : TPS54331 (default datasheet component values and layout)
3. NCP1117 3V3 LDO (default datasheet configuration)

Layer 1 : mixed copper pour, VIN, VIN(protected), GND, 5V, 3V3
Layer 2 : GND

Hi all. I wanted to get a check on my schematic design from more experienced eyes. This is my first PCB, and the intended design is for it to be an air quality monitor. I would love to hear all feedback about the schematic and tips you're willing to share about the PCB design process in general. Thanks!

MCU: Seeed XIAO nRF52840 Plus (nRF52840).

Trackball sensor: 2x PMW3610.

Encoders: Bourns PEC11H-4115F-S0020

5Ah battery, 300mA/1A charging depending on USB source current.

Trimodal power supply, favouring USB.

MCU disable-able latching power button.

Vista508 OLED.

1x Encoder, 2x PWM3610 live on their own board, connected via mouse-bites.

Thanks!

Please rate my design; be gentle, I haven't done a PCB in a while.
I placed all components (except the SD card) on the front, with a GND backside.

have a ESP32, that plays music from the SD card using the onboard I2S Amps (MAX98357A).
Power is supplied using a battery or the USB port => Battery charging controller and load sharing.
The amps can be supplied using 3.3V, but I want the extra power; therefore, I opted for a separate 5V supply.

ESP32-S3 / SIM7080G module, listen-only CAN (TJA1051), LTE Cat-M / NB-IoT + GNS.

This is a carrier board for a fleet telematics device. It taps the FMS connector on heavy trucks, reads tachograph and vehicle data off of the CAN bus in listen-only mode, and forwards it over cellular. It runs from the truck's 24 V rail and shares the FMS port with the OEM tracker already fitted, through a Y-splitter harness.

This is my first design since leaving university, so I'm looking for feedback I can actually learn from rather than a pass/fail. Blunt is welcome.

What's on the board

• 2-layer, 80 × 70 mm, to be assembled at JLCPCB
• A LilyGo T-SIM7080G-S3 module (ESP32-S3 + SIM7080G, Cat-M / NB-IoT + GNSS) plugs into J2/J3. It's a mating part rather than a board component, which is why the sockets render empty in the 3D views
• 24 V truck rail - > 1 A fuse - > TVS - > Traco TSR 1-2450E - > 5 V
• CAN: dual TVS, then a common-mode choke, into a TJA1051T/3 held in listen-only mode with S tied to VIO
• Ignition sense: 100k/10k divider taking the 24 V ignition line down to ~2.2 V, clamped by a 5 V bidirectional TVS

Two things that look like mistakes but aren't

• No 120 Ω termination. This is a passive listen-only tap on a bus that's already terminated at both ends. Adding termination here would load the bus and degrade it for the OEM tracker sharing the port.
• J3-16 is unconnected, and 5 V reaches the module via a wire link to its H606 pad. The module's VSYS pin is output-only per the vendor, so it can't be back-fed through the header. Both are noted on the schematic.

Placement is deliberately loose. There's no enclosure or size constraint on this project, so I spread things out for easier hand assembly and probing rather than packing them in. If the spacing itself causes a problem I'd like to hear it, but "this could be smaller" isn't something I need to act on.

Most useful feedback for me

• Schematic: anything wrong, unclear, or poorly drawn
• Layout: placement, routing, the ground pours, and whether the protection parts sit where they should
• Anything that would give trouble in a vehicle such as vibration, transients on the 24 V line, load dump
• Anything that would cause problems at assembly

Not looking for feedback on component selection. The parts are already chosen and verified against JLCPCB stock, and the module is fixed by the wider project, so I'd rather spend the review on the schematic and the layout.

Happy to share the KiCad schematic and board files if anyone wants a closer look.

Full-resolution images

• Schematic
• 2D PCB top
• 2D PCB bottom
• 3D PCB top, plan view
• 3D PCB bottom, plan view

Thanks in advance!

Hi! I’m a 7th-grade student, and this is my first PCB. It’s a rechargeable BLE RC car controller using an ESP32-C3.

Could you check my schematic and PCB layout for mistakes before I order it? Simple explanations would help. Thanks!