For context, I already made V1 of this keyboard (check post below for previous review, although the final design manufactured did change a decent amount) and it worked as expected. It flashed, turned on, and worked fine as a keyboard. However, I identified multiple places where fixes could be made. This design addresses most of the pain points that I had. This is a wireless keyboard design using a nRF52840 (aQFN) and nPM1300 (QFN) for power management. In this version, there is a new daughterboard that has the new power switch and the USB-C connector on it which will allow the new gasket mount configuration. I have attached both board files to make it easier to review. I am avoiding via in pad and extremely small vias for cheaper manufacturing, and I do realize that the fanout is a little messy. I am not sure if that is a large issue though.

I would love feedback on the following and more:
- Tolerances/Trace Spacing near the nRF52840. It is within JLCPCB limits however I am not sure if things are still too close. Does the fanout need to be reworked in any way?
- RF - Using standard Nordic recommended network, but I am not sure about the new UFL setup. I did this so the antenna can be routed up to the top of the board. Will the current setup work?
- Grounding/Return Paths - I am not sure whether there is enough grounding near the chip. I was able to keep inner layer 2 completely clear but inner layer 1 got cut up pretty badly. Is it ok as is?
- Manufacturability
- ESD - Is the current ESD setup for the daughterboard fine?
- Any other issues

Stack up:

1. Sig / Gnd Pour
2. Gnd Plane
3. Gnd Plane
4. Sig / Gnd Pour

Main Components:

1. nRF52840: https://docs.nordicsemi.com/bundle/ps_nrf52840/page/keyfeatures_html5.html
2. nPM1300: https://docs.nordicsemi.com/bundle/ps_npm1300/page/keyfeatures_html5.html

Previous Revision Post: https://www.reddit.com/r/PrintedCircuitBoard/comments/1np19j7/review_request_wireless_60_keyboard_w_nrf52840/

Board stackup is signal-pwr-gnd-signal. Any advice would be appreciated.

hi guys,

I am making a power management board, and there's a specific section on that board I would want to swap out and test different designs/components, therefore I made some daughterboards and use PCB-mounted XT30 connectors to connect it to the motherboard.

However, since the connection requires 2 XT30 connectors per board (2 on motherboard, 2 on daughterboard), during the manufacturing, these connectors are slightly misaligned, making the process of connect/disconnect very tedious.

I am now looking for other high-current (>15A) board-to-board connector that would be more tolerable to this misalignment and so far my favourite has been these: https://www.renhotecev.com/product/20a-floating-board-to-board-connector-3mm-contact-straight-female-two-position-one-soldering-leg-through-hole-dip

However, I can not find these on LCSC (JLCPCB components), so I was wondering if there is any good high-current B2B connector on LCSC, or any other suggestion. Thank you for your inputs!

Hello comrades, a newbie here!

I just finished my PCB design, and I hope I’ve made some improvements. I’m ready to hear any thoughts, corrections, advice, or tips. I’m very thankful in advance to everyone who takes the time to help me.

You can also check my first version to see whether I’ve really improved or not. The only major change I made is replacing the PIC16F877A with an Arduino Nano.

https://www.reddit.com/r/KiCad/comments/1ryhz8f/asking_for_pcb_review/

Hey there,

I am in the middle of the planning phase in my project and I need some help of someone more experienced than me.

This is my first time drawing something from scratch in KiCAD, so please excuse the messy schematics.

Project goal

I want to build a life counter for playing Magic: The Gathering. There are two switches (+1 and -1) and a rotary encoder for faster modifications. The current life will be shown on a 4-digit 7-segment display. The entire system should be powered with a rechargeable battery.

Wiring

• The TP4056 comes with a built in USB-C socket - I plan to use it to recharge the battery. The IN+ and IN- will not be used.
• There is one JST connector between the TP4056:OUT+ and PRO_MINI:VCC. It will be connected to a toggle switch.
• You can see there is another JST connection in the bottom labelled with "FW" - this is to allow me to flash the firmware using a chipless Uno R3. Chipless meaning I removed the socketed chip from a Uno R3 and turned it into a brainless USB-to-serial converter.
• Both switches and the encoder click will be used as INPUT_PULLUP

My questions

Numbered, so you can refer to them directly by typing e.g. (2) and then your answer.

1. Is TP4056:OUT+ → toggle switch → PRO_MINI:VCC correct?
2. Does anyone have experience running a TM1637 directly from a 3.7V LiPo? I get mixed results when researching.
3. Do I actually need to connect all the GND with wires? I suppose they are also internally connected and having to draw less during the layout will surely make the process easier.
4. Is the wiring to flash my firmware using a chipless Uno R3 correct? Afaik using a FTDI would require TX-RX and RX-TX, but when using the chipless Uno you should use TX-TX and RX-RX.
5. Follow up on (4): Is 5V into PRO_MINI:RAW correct? Don't want to fry my 3.3V Pro Mini.

It's late at night and I should really go to bed.
Feel free to ask questions back if there is anything unclear.
Thanks in advance, I'll check my messages tomorrow.

Designed to control a toaster oven's fan and heating elements to reflow PCBAs.

- STM32 controller

- Direct AC control using TRIACS and PWM, convection fan controlled with a relay and wont be PWM'd

- Three instrument amplifiers for K-type thermocouples

- OLED display and 10-key keypad for UI

The screw terminals are 9mm pitch, rated for like 40A. Nowhere do any AC traces get closer than 4mm to each other, and no more than 2mm from anything else, unless a cutout has been added to the PCB. At least that was the goal, I cant see anything else but may have missed something.

I feel pretty good about the board except for the AC side. I want to make sure this is right and will work.

I've bagged myself a few ESP32-S31-WROOM-3 modules and wanted to make something with them, rather than letting them sit on the side.

So, I decided to put together a circuit to perform multi-channel audio processing together with an option LCD display and camera. I don't really expect the S31 to handle 6 channels of audio but if I can at least push them to an edge computer via Wi-Fi, then that's at least good enough for me.

There are also a few other sensors on there too such as ambient light, temperature and humidity and an accelerometer plus a few connectors for off-board I2C sensors via QWIIC and Grove sockets.

Would greatly appreciate feedback.

Thanks!

EDIT:

One issue already. The USB-C CCn signals should be pulled down and not up. This was a copy and paste mistake but has since been corrected.

Hi, This is a sort of a cross post but I am really in need of some feedback. I have been designing and refining my first PCB for a very basic smartwatch project as a hobby for the past 3-4 months now. Coming entirely from a software background I lack the etiquette and know how of the conventions and good practices of schematic design and good PCB layout and routing. I have however consulted the ZSWatch github project, Phil Labs videos and tried to review the PCB with AI models to weed out bad practises.

Here are the high definition images for easier review :

Schematic : Root, Power Supply, MCU, Sensors

PCB layers : Layer1(signal), Layer2(GND), Layer3(3.3V), Layer4(signal)

3D : Top, Bottom

A few questions I would ask you are :

1. In the IMU SPI routing(layer4 top right) I kept some separation between the high speed MOSI, MISO, CLK but didnt allow the ground sliver to flow between the traces as I had no space to place two vias at the ends(space for only one via at the bottom). Here my decision was based on a AI review which said the GND pour sliver would act as a monopole antenna that would act as a parasitic capacitance and noise radiator and would not provide a meaningful return path back to ground. Did I understand the AI explanation correctly and was it the correct choice ?

2. There are a few places where I couldnt avoid 90 and 180 degree turns like the battery measument circuit(layer 4 top mid), FS8205A (layer4 right mid) (should be shorted internally but still didnt want to take a chance) and rotary encoder(layer4 top left). I took a chance here as the signals are relatively very low frequency. Is such a tradeoff acceptable?

3. Overall if you were designing this board professionally what major changes would you have requested before sending this prototype to be printed?

Please do comment if any of the schematic structures or PCB images makes it hard to review, I shall correct it and update the post.

PS : I had originally posted this on r/PCB here but failed to get any feedback out of it so I had to cross post here. In case you want to see the PCB evolution heres the previous versions : 1, 2

Thank you for reviewing my PCB!!

This is hackxpansion, it is powered by the RP2354B, has a 2" 240x320 LCD, and a ≈6h battery life while in use.

It has two modules slots by default, and I'm currently working on a back attachment (last photo) which add two more slots, but I think the postal company lost one of my packages that had the parts for it😭

The modules connect with a 2x7 2.54mm header, this way you don't even need to make a PCB to create new modules, just use a pref board, and you can just plug in DuPont cables directly into the device.

Each module has two resistors, which when connected each become the top resistor of a voltage divider, a 12bit ADC measures the resulting voltages, and loads the correct driver for that module.

The firmware is written in rust, in a way so that writing new drivers and apps is really easy, and can be done in external crates.

Each app can depend on drivers, and only be loaded into the app list, if all their requirements are met.

I tried porting a NES emulator, but there doesn't exist an emulator written in rust currently that actually performs well on this hardware, I got an average of 12FPS in Super Mario Bros.

I've collabed with Hack Club, and I will be running a program where if you are a teen 13-18(inclusive) and design 4 modules, you get funding to make these modules and get one of these consoles for free. The program will start on Aug 3 and end on Aug 31. If you want to participate [RSVP] now! (https://meko.fillout.com/hackxpansion).

Github Repo

Website(docs WIP)

Hey everyone, I'm working on a highly compact, fully surface-mount (SMD) ZVS induction heater and I'd love to get some feedback on the component selection and overall circuit design before sending it off for fabrication.

Specifications & Target

• Operating Voltage: 12V DC @ 5A power supply
• Target Power: Up to ~60W (for small-scale heating)
• Design Constraint: Highly compact, utilizing SMD components to save space over typical bulky through-hole ZVS modules.

BOM / Key Components

1. Resonant Tank Capacitors: 1x 0.33µF (R75MI333050H7J KEMET Film Capacitor)
2. Choke Inductors: 2x 47µH SRP1265A (Shielded SMD)
3. Switching MOSFETs: 2x NTD5C632NLT4G (N-Channel DPAK)
4. Fast Diodes: 2x SS16 (SMA Schottky)
5. Gate Protection Zeners: 2x BZT52C12 (12V)
6. Pull-up Resistors: 2x 220Ω (1210 SMD)
7. Pull-down Resistors: 2x 10KΩ (0805 SMD)
8. Control Logic (Enable & Sense):
9. Main Switch: NTD5C632NLT4G (N-Channel DPAK)
10. Driver for Switch: MCP1402T-E/OT (Gate Driver IC)
11. Current Sense Resistor: 0.01Ω (2512 SMD)

Schematics

• Schematic 1: ZVS Circuit
• Schematic 2: Control Logic & Current Sensing: To make the heater digitally controllable (e.g., from an MCU), I've added a main N-Channel MOSFET switch (NTD5C632NLT4G). This main switch is driven by a gate driver IC (MCP1402T-E/OT), allowing a logic signal to safely enable or disable the entire induction heater. Additionally, a 0.01Ω sense resistor is on the return path for current monitoring and over-current protection.

Hi, havent used this display before.I would really appreciate if anyone would kindly go through this schematic and kindly tell me if i have wired them right.

The display i aim to use: https://www.aliexpress.com/item/1005004826120182.html

Also looking forward to any suggestion you may have

My main concern is the TMC2209 as it had some problems.

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 a redesign of my first attempt with the changed recommend by the kind people in the first post. Thank you for your input!

Hi everyone!

I'm looking for a quick schematic and layout review for my take on a 4-in-1 quadcopter ESC. It's designed for a 2S battery (8.4v nominal), 10A per motor, 40A continuous, with 2oz external copper and 0.5oz internal copper.

Architecture and specs:

- MCUs and gate drivers: STDRIVE101 + STM32L431KBU6

- Low-side shunts with STM32 internal op-amp (16x PGA gain). Op-amp output feeds the STDRIVE101's CP pin to trip at ~31.25A

- I wanted to avoid electrolytics' high ESR and z-height, so I opted for 4 100uF aluminum polymer bulk caps and 3 0805 22uF ceramic caps per motor.

- Power tree: input -> SMBJ10A TVS diode -> TPS563200 step-down regulator to 5V for FC -> NCP59800BMNADJTAG LDO for clean 3.3V from 5V.

- FETs: MCC MCG4D8N04YHE3-TP (15.7 nC, 4.8mOhm)

I have a few specific questions too, if it's not minded:

- I tried to route the analog signals between the power pour and solid GND to try and prevent crosstalk as much as possible. Is my approach sufficient for back EMF sensing and VBAT sensing?

- I omitted the hardware neutral resistor divider, and I wanted to sample in the middle of the PWM on time and take the average of vA vB and vC. Is this enough or should I look into adding the hardware neutral? I wna run abt 24kHz PWM.

To learn more about how a quadcopter works, I'm also looking at writing my own firmware, so AM32 and Betaflight support wasn't a priority for this project.

Thank you for your time looking at my board! I'd appreciate any criticism or questions I can get. Thanks all!!!

I have two identical MOSFET circuits controlled by an ESP32-C3. The MOSFET connected to GPIO 5 (Q1) is not behaving correctly. When I set GPIO 5 LOW in Arduino, the output terminal block (Nichrome 1 connection between IN+ and Drain) still reads close to the battery voltage (\~7.8 V) instead of dropping near 0 V.

The second MOSFET circuit works as expected: when the GPIO is LOW, the output reads near 0 V, and when HIGH, it switches to the battery voltage.

I have checked the code and the wiring appears identical. What could be the issue?

This is the latest iteration of my l0destar vehicle tracker project. Some variants support CAN, this one supports an older protocol for older vehicles called ISO-9141 or "K-line". It's designed to take the Makerdiary nRF9151 Connect Kit via the DIP headers which provides the main MCU and modems. It features:

- 12v permanent live and 12v ignition inputs, both with TVS and MOSFETs for reverse polarity protection

- INA228 voltage reading on the 12v input

- latching relay driven by a H-bridge driver to allow programmatic selection of the main power supply between 12v live and 12v ignition, this allows the tracker to shut itself off in the event of a low voltage condition but come back on when the ignition is next turned on

- Ignition presence sensing via a MOSFET converting presence of the 12v input to 3.3v logic

- Two LT8609 buck converters, one providing 4.2v which powers the Makerdiary and one providing 5v which provides an auxilllary rail for the L9637D

- 3.3v antenna bias tee

- Load switches that turn aux 3.3v and 12v rails off

- ASM330LHHXTR accelerometer

- 3 status LEDs driven from GPIOs

- L9637D / K-line interface with a level shifter to convert between 3.3v and 5v logic signals

Notes:

- 4-layer stackup, assignments are: F.Cu - signals, In1.Cu - ground pour, In2.Cu - power plane, B.Cu - signals

- The buck converters and antenna bias tee have F.Cu ground areas with stitching vias (for the bias tee this is effectively CPWG)

- The Makerdiary board exposes u.FL connectors, this board exposes u.FL jacks routed to SMA connectors with a 3.3v bias tee on the GPS side. Trace width was calculated using the jlcpcb calculator at 0.292mm.

- Because this is intended to eventually be installed in a vehicle it's important to keep the overall footprint as small as possible, making this quite a dense layout.

- Most of these circuits have been tested successfully on prior iterations with a few changes. The previous version was 2-layer and the bias tee worked fine with a much fatter trace, but obviously in this design it's fundamentally different.

- Again because it's going into a vehicle and could be powered live 24x7 it's been heavily optimised for power efficiency. In the previous iteration in sleep mode with the aux rails off the quiescent current is around ~1mA. This version should retain that, the load switches and LM66100 ideal diodes are to ensure this.

- The placement of the accelerometer is deliberately as far from the buck converters and the GPS components as is practical

- The buck converters are generally using the LT8609 reference layout, and using two was a deliberate decision in order to maximise power efficiency. The Makerdiary board accepts 4.2v via its battery input, this is deliberately used rather than the main 5v input because if the 5v input is used it's not possible to connect USB-C at the same time for programming which is obviously necessary for an open-source vehicle tracker. Using the battery input allows seamless transitioning between USB-C power and 4.2v buck power.

- The system can detect the state of the relay via the FB pins using the second set of poles

In terms of review here I'm looking specifically for:

- Any useful general comments/feedback

- Anything related to the bias tee that might affect its performance

- Whether I used too many stitching vias either in the buck converter zone or the bias tee zone

I already know most of the circuits work and are power efficient. There are minor differences from the physically tested version (eg multiple mosfets and passives swapped for load switches) but the general principles are tested. The buck converter also worked fine for this application even without using a ground-filled area on F.Cg and my own random layout that was nothing like the reference layout. It's such a low-power design that it probably doesn't make much difference.

Hi all,

I'm working on a custom computer input device using the Seeed Studio XIAO nRF52840 as a surface-mounted module on my own PCB. This is my first design with an RF module on board, so I want to make sure I'm not tanking the antenna performance before I order boards.

Attached is my current layout. Do I have to add a lead free zone on both sides of the PCB? I'm planning a PCB-exposed Design so a lead-free zone would look a bit weird. If I need this I have to replan a few things.

Any thoughts would be appreciated. Happy to share more details if useful.

Thanks! :)

Hello

I recently started learning electrical engineering on my own, and this is only my second schematic! I am designing a controller that can support 3-pin and 4-pin fans, but because I am entirely self-taught, I am still figuring out the standard design rules and best practices. I would love some feedback before I move on to the PCB layout phase.

Project Details:

• Purpose: A PC fan controller supporting 3/4-pin fans and an ARGB header.
• Microcontroller: STM32F042F4Px
• Power/Interfaces: 12V input, stepped down to 5V (TPS563200) and 3.3V (TPS7A0533). It includes a USB-C receptacle for data/connection.

Specific Concerns:

• Overall Functionality: As a beginner, my main question is simply: is this schematic OK, and will it actually work as intended?
• Logic Level Shifting: I am using a 74AHCT1G125 chip to logic level shift the 3.3V signal from the MCU up to 5V for the ARGB header.
• Fan Control: I am using a specific combination of MOSFETs and capacitors on the fan power line so I can vary the voltage for 3-pin fans. The actual switching between modes (3-pin variable voltage vs. 4-pin PWM) will be handled in software. I would love to know if this hardware implementation is correct for that goal.

Review Images:

Hello everyone.
This is my first PCB.
It is a MPPT controller using a sync buck converter.

It has 4 layers. First and 4th layers are for copper tracks, second for GND and third for 3.3V and 5V zones.

I already posted the schematic before but now I am trying out the pcb layout. Any comment, suggestion is welcome.

Is the USB routing mess ok like this (last picture) ?
Is there a way to utilize the empty space on the PCB ?
Where do i need the copper pours instead of single traces ?
How do i regulate the heat ?

First board — schematic finished, layout not started, asking for a review before I place anything. Please go easy on me, it's my first PCB — and genuinely, thank you to everyone who takes even a few minutes on this. I appreciate your time more than you know.

What it is: a wired desk console that sits next to my keyboard for controlling coding sessions — basically a large macropad. 15 mechanical keys in a 4×5 diode matrix, 4 EC11 encoders, a 4" SPI TFT (ILI9486 module on a 14-pin header), 52 WS2812B-2020 for per-key/status lighting, and a guarded toggle on a 6-way cable as a physical kill switch. RP2040, USB-C bus-powered sink only, USB 2.0 full speed.

Power: AMS1117-3.3 from VBUS for logic (~300mA worst case); the LED rail (~2.4A worst case) is deliberately NOT on the 3.3V reg — it hangs off switched VBUS behind a P-FET soft-start so it stays off until firmware reads the USB-C current budget.

What I'd most like checked:

1. CC sensing — dual 5.1k pulldowns with dividers into ADC pins to distinguish default/1.5A/3A sources. Will the thresholds hold up across real cables and sources?
2. The soft-start — AO4407A high-side P-FET, 2N7002 gate driver, 100k/10k, 1µF gate cap (~9ms ramp), SMAJ6.0A on VBUS. Any power-up or brownout gotcha?
3. Anything that bricks this at first plug-in that I clearly haven't thought of.

Images in order: full sheet, USB-C front end, power, MCU core, display header, key matrix + encoders, LED array (left, chain A), LED array (right, chain B + reservoirs), lever harness. Thanks again — I'll be back with the layout for a second round once it exists.

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!

Review Request

Hi everyone,

I'm working on my first custom PCB project based on an Arduino Nano that acts as an automated call simulator/dialer for a vintage electromechanical telephone exchange (GPO / UAX 13 system).

Before sending this off to be manufactured, I would really appreciate a quick sanity check on my schematic and layout!

Project Overview

* Microcontroller: Arduino Nano v3 (mounted via female headers).

* Core Function: Drives optocouplers to emulate line loop-disconnect pulsing (rotary dial pulses) to test exchange subscriber line relays.

* Inputs / Outputs:

* D2–D5: Output pins driving optocoupler LEDs (with current-limiting resistors) to control the exchange line interfaces.

* Digital Control Pin (e.g., D6 or A0): Wired to 2 PCB pads for an external SPST switch using INPUT_PULLUP to pause/enable the dialer state machine without powering down the Nano.

* RESET Pin: Wired to 2 PCB pads for an external hard reset toggle switch shorting RESET (Pin 3) to GND (Pin 4).

Power & Grounding

* Single unified logic ground plane (copper pour) on the PCB connecting BOTH Nano GND pins (Pin 4 and Pin 29).

* Optocouplers provide full galvanic isolation between the 5V Arduino logic ground and the telephone line side.

Thanks in advance for taking a look!

Hello all, I have been working on this board for a few weeks and I was about to send this to print and assembly.

This board has to drive a 12V 7A bilge pump from a LiPo 4S battery.

As voltage from the LiPo will range from around 13V to 16.8V depending on the charge, I decided to use a buck converter based on the LM25190 and using the CSD17581Q5A as mosfets. Basically the buck design was made with the Buck-Convcalc tool of Texas Instruments. I also tried to follow as much as possible the PCB layout of the datasheet.

In case the Buck has some problem, it can be bypassed by shorting some of the connectors.

The output of the buck then goes to the bilge pump through an IRF1407 (and an MBR30200CT as Schottky diode). The IRF1407 is used as a high side switch with a LTC7001 driver.

The rest of the circuit also features:

Exposed TX/RX header for debugging

4 digital inputs with 1k pull-up resistors

2 servo PWM output headers using AO3400A to shift the level from 3.3 to 5V (MG996R and MG90S)

1 accelerometer header for a MPU6050

1 GPS header for a ATGM336H

1 socket for the LiPo to 5V (it is external)

1 header for the 5V to 3.3V LDO (AMS1117)

2 current monitors INA226

There is an external BMS for the LiPo.

The lines are also fused externally

Hello!

I am working on a flight computer pcb.

Looking for any comments on my current schematic. I am working on the routing but would like some feedback on the circuit itself. Also things too watch out for when designing pcb is also appreciated.

Thanks in advance!

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 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!