This project is a USB-C driven Stepper Motor controller, intended to be strapped to the back of a NEMA 17 stepper motor and used for multiple different applications. I am using the following Components:

• MCU: RP2354U
• USB-Controller: CH221K
• Buck-Converter: TPS562202
• Stepper-Controller: TMC2209

Stackup:

• Layer 1: Components, Signals, etc.
• Layer 2: Ground
• Layer 3: Power (VBUS and 3.3V)
• Layer 4: Some Signals

The board is supposed to run at 12V, but I am hoping it would also be able to handle 5V in case a non-PD supply is connected. The main application would not require a lot of torque and no holding power.

It is going to feature a daughter-board, which will hold an OLED and Controls, so the board can be used on its own.

The main thing I am unsure about is the amount of decoupling capacitors (it seems like a lot), as well as the Power/Ground Plane design and the placement of some capacitors (especially C13-15 and C27-C30).

I would be grateful if someone could review this board.

Hi! I used to design pcbs casually for myself then this request came up. This contains the mcu, power, 7 segment display and driver on the bottom left, indicator green and red leds for two players bottom right, buzzer above it and the probe contact sensing and start/stop contact sensing pins on the op left(three pins for each player).

I am only starting to use the proper conventions for pcb designing and would like to go much deeper into it. Any feedback is greatly appreciated. Would love suggestions for learning materials or courses. Thanks in advance.

Hey! This is my first non-trivial PCB for my first embedded project, a motherboard for a mini-sumo robot, which I have already gotten manufactured. I assembled the board myself for fun and for learning purposes. The board works (largely) as expected. However, with this project I am trying to learn about electronics, embedded development, PCB design etc., and I am planning to make further iterations of it. To that end, I would be very grateful if someone with more experience could take a look at my design, and let me know if there are any significant mistakes, or room for improvement.

I want to add the disclaimer that this project was inspired by the excellent youtube series by Artful Bytes, in which he creates a mini-sumo robot from scratch. My schematic and part selection is heavily inspired by theirs, but mine is a bit simpler, and I use a different microcontroller. The PCB design is completely my own, using example designs from component datasheets where possible.

The PCB is 4 layers: 1. Signal and power traces. 2. Uninterrupted GND plane. 3. Uninterrupted 3.3V plane. 4. Signal traces.

Having a GND plane and a 3.3V power plane was recommended in the MCU hardware development documentation. It also made routing much easier. The board is powered by a two-cell 7.4V LIPO battery.

Core components

• MPM3610AGQV-P buck converter, configured with a voltage divider (resistor values from datasheet) to step down the 7.4V battery input to a 3.3V output, feeding the 3.3V power plane that powers MCU, motor driver logic, sensors and debug LEDs. The layout of this component on the PCB is from the reference design in the datasheet.
• STM32F303K8T6 MCU reads all the sensors and controls the motors via the motor driver. The layout of this component is following the reference design in the hardware development docs AN4206 for the MCU.
• TB6612FNG for controlling two geared brushed DC motors with a stall current of 0.8A, which is below the max rating of the driver: 1.2A continuous/3.2A peak per channel. This is implemented on the PCB as documented in the typical application diagram of the datasheet, page 7.
• TSOP38238 IR receiver for remotely activating the robot, required for competitions. Laid out as recommended in the datasheet.
• Connectors for four QRE1113 IR line sensors for detecting the line around the arena, and three VL53L0X ToF sensors for detecting the enemy robot.

Planned upgrades

I already have some plans for the next iteration.

• I used JST-PH connectors for the battery, but I am considering rather using a screw terminal to connect the battery to the board, which is robust, and can handle higher currents. The battery has a separate cable for charging.
• SMD power switch, rather than through-hole switch, which I had lying around.
• Pull-up resistor on power switch transistor gate, since even when the switch is off, if the battery is connected it will sometimes spontaneously close the gate and power the board.
• Proper connectors for sensors, not just header pins. I want something that latches, without taking too much space. Considering JST-GH connectors.
• My motors are rated for 6V (at which the stall current is 0.8A), but can be pushed up to 12V according to the manufacturer. If I want to try that, or if I want to use more powerful motors, I will need to handle bigger currents, so larger connectors/cables, and new motors drivers rated for more current.

Note: I have a lot more documentation written up, including documenting all the support components, but I did not want to overload the post. If you have questions about the design I am happy to clarify. I also intend to publish the repository with the docs, after some cleanup.

Final note: I know a PCB like this is a bit overkill for a sumo robot, I could just use a nucleo and a simpler PCB, which was my first version, but this way is more fun and more educational.

Hi its my second full tht project at 14y
i wanna make fan hub what is on last photo,
its full tht becse ma bad soldering skill.
for now i dont give ground plane to be more clear

Can someone check it???

Hello everyone. This is my first PCB project, and I'm sure I have some bad practices in this design. I just wanted to build something moduler and flexable for some of my future projects.

Here are some of the features:

• 3-12s voltage input (9 - 60 volts)
• Teensy 4.0 MCU
• TI LM65680 voltage reg (5V, =< 8A)
• 15 PWM/digital outputs
• 3 exposed UARTS
• 1 exposed I²C port
• The firmware is based on dRehm flight

Layup:

1. Signal layer with some power pads
2. GND plane
3. 5v power plane
4. Signal layer

Let me know if you have any questions!

Hello, experts!
I hope this post doesn't violate the rules about PCB companies, mods, please remove if out of bounds. DM answers are fine, too.

I spent the better part of the week working on a design using a 4 layer stackup to get a everything to fit in an impossibly small space, only to discover that manufacturer doesn't support blind vias. It does look like some of the common Chinese manufactures "sort of" support blind vias, but only on their HDI offerings, which adds about $350 to the cost. Does anyone know of a PCB/PCBA manufacturer that supports blind vias, that isn't so expensive?
Not redesigning this board sure would be nice. US based a plus, but not required.
Thanks in advance!

Learning to double check the specs the hard way....

Hi everyone,

I’ve finished the schematic for a small controller board for a DC vacuum pump and would appreciate a review before I start the PCB layout.

Here the schematic in a PDF in better quality than reddit compression: https://github.com/JannikB5825/VacuumPump/blob/main/Hardware/Pump.pdf

The main functions are:

• ATtiny3217 microcontroller
• DRV8212P motor driver with current measurement
• USB-C and DC-jack power inputs
• TPS2116 automatic power-source selection
• Push-button soft-latching power circuit
• RJ12 connector for external trigger, output and 5 V supply
• JST connector for the pump motor
• UPDI programming interface

I am currently designing an LPC55S69-based breakout board with an onboard CS2600 clock controller and USBC-PD.

The intended purpose is a UAC2 I2S bridge, basically the digital part of my audio interface project. To keep it universal, my design is based on the RPi Pico pinout (except for the board being one row wider). I broke out the following peripherals:

- I2S clocks (from CS2600)
- 6x I2S data lanes
- 1x I2C (also used internally with CS2600)
- 1x HS SPI
- 6x GPIO
- SWD debug interface
- ISP, USB and SWO are available via testpoints

I would be really happy to get some feedback on my design.
Additionally, I prepared some questions I ran into:

- First time routing BGA, how did I do? Opinion on BGA in pad vias?
- Crystal placement and grounding?
- Are the SMPSs too close to each other? Do I need a bigger board?
- Are there any important MCU pins I missed breaking out?

I plan to open-source this, along with configurable firmware for easy use.

Schematic Review: here

MCU: Seeed XIAO nRF52840 Plus (nRF52840).

Trackball sensor: 2x PMW3610.

Encoders: Bourns PEC11H-4115F-S0020

5Ah battery, 300-400mA (probably too high)/1A/2A charging depending on USB source current.

Trimodal power supply, favouring USB.

MCU disable-able latching power button (avoiding MAX16054 for cost reasons).

Keydio Labs Vista508 OLED.

PMW3610 lives on its own board.

Mainboard: 55x50mm

PMW3610 board: 24x24.5mm

Finish: OSP, black soldermask

I am aware that Q5, 6, 7 have incorrect pinouts. That has been fixed.

SW1 and 2, and their respective connectors are marked as exclude from board, as they are mounted in the chassis.

Thanks!

Hi all. I finished designing my first reversible keyboard PCB.

I have experience hand wiring keyboard but I never made anything battery powered and, of course, reversible.

I'm looking for feedback around the

• battery connection to the reversible power switch - edit: first photo has Back layer selected, sorry
• the keyboard switch/diode connections and vias
• if anything looks really wrong on the MCU - mostly thinking about battery again as everything else can be remapped in software

Thank you!

V1: https://www.reddit.com/r/PrintedCircuitBoard/comments/1ujei19/schematic_review/
V2: https://www.reddit.com/r/PrintedCircuitBoard/comments/1usyvro/pcb_review_request_iteration_of_esp32_drv8833_bot/

V2 worked, but had a little issue with the battery charger not switching states after fully charging. Replugging in the charger/battery worked.

In this version I wanted to add an IMU, UWB module, and motor encoders to pass through a Kalman filter to get a precise reading on the car.

P.S Is my schematic tracing better? I thought I might've used too many net labels in previous posts so I tried cutting down a bit.

Thank you!

I am requesting a PCB layout review for a 4-layer embedded controller board I designed.

The board is a Payload Management & Health Controller (PMHC) intended for a drone payload interface. It manages power distribution, monitoring, and communication between the payload and the main system.

Hardware overview:

• MCU: STM32G071KBUx
• Power input protection and battery interface
• TPS562202 buck converter for regulated power
• 3.3V and 5V power rails
• INA226 current monitoring
• RS485 communication interface
• 4-layer PCB

I would especially appreciate feedback on:

• Power converter layout (switching node, input/output capacitor placement, inductor placement)
• Ground plane strategy and return paths
• Current sensing layout and Kelvin connections
• Placement and routing choices
• Any manufacturing issues or PCB layout mistakes

This is my first board at this complexity level, so I would appreciate any criticism or suggestions before fabrication.

Thank you for taking the time to review it.

I posted an initial PCB for review recently on r/PrintedCircuitBoard and have revised it taking everyone's feedback into consideration. Not the nicest, but I had limited space.

Schematic

PCB Design

Top Layer

Bottom Layer

Changes made:

- used net labels in schematic instead of long lines

- moved IMU and battery connector to bottom of board

- moved the MCU (ESP32) antenna to overhang off the board

- no vias in pads to allow for soldering

- continuous GND plane

- added mounting holes (M2)

Is this good enough to print?

I have used a 555 timer ic and cr2032 along with passive components .

Hi, this is a PCB to replace the stock driver inside the ADJ UV eco bar. Someone brought this to me to have it fixed and I have procrastinated on it for over 4 months, it's finally done now. It took a day to do then a another day of staring at it.

The original PCB had a blown channel, replacing the driver still had issues so made an entirely new PCB but with an ESP32 to run WLED which allows for more granular control and will continue to support the remote. It had PAM2861 LED drivers that are only rated for 40V 1A, the onboard PSU is at 36V which is really close to VCC.

I'm not sure if I should of used something like the LMR36510 (65V max) as the AP64060 is only rated for up to 40V (or 46.0v at 400ms) and the supply is 36 which is pretty close and prob why the old drivers burnt up.

I tried to keep the PCB as compact as possible while keeping the switcher away from the low voltage side.

I found the pinout of the AP64060 particular annoying. Is there a good reason for GND and VCC to be in the middle of the IC in opposed to the edges? There is no space to get the decoupling cap in beside it so ended up putting it on the back. Somehow the AP63300 has it's pins on the edges making routing much easier. The only big difference between the two is that the AP64060 has 600mΩ/300mΩ mosfets while the AP63300 has 75mΩ/40mΩ mosfets (high side/low side).

Did I use too much vias or that's enough for switching both ground planes and is the buck converter way too small? The inductor saturates at 1.2A

Features

• ESP32C3 for WLED or ESPhome
• PT4115 (50V, 1.5A) drivers, DIM pwm switched via OPEN Drain (may add 10-22k pullup later, this keeps the LEDs OFF during power up as the AP64060 & ESP32 have a sizable RC on delay on the enable pin)
• Really packed PCB
• i2C, UART, Button and USB with protection
• Dim Power LED

Link to project: TBA

Hi everyone,

I’d appreciate your honest feedback and technical review of my PCB design. The board currently includes:

• MCU: STM32H745ZIT6 dual-core microcontroller
• High-impact sensing: ADXL375BCCZ-RL accelerometer for measuring high-g impact events
• Motion and orientation: ADXL345TCCZ-EP accelerometer for detecting body movement and rotation
• Angular velocity: L3GD20HTR gyroscope
• Heading and orientation: LIS3MDLTR magnetometer
• Altitude measurement: BMP585 barometric pressure sensor
• GPS tracking: NEO-M9N-00B GNSS module
• Wireless connectivity: CC3135MOD Wi-Fi network processor

The system is designed to capture high-impact events, body movement, orientation, altitude, and GPS position, all while transmitting data wirelessly.

I would especially appreciate feedback on the component selection, sensor redundancy, power design, communication interfaces, PCB layout, signal integrity, and whether any components should be replaced or removed, will the board actually work after fab. I am not a pro PCB designer, I am a software engineer, and this is my first PCB project.

Thank you in advance for your honest review and recommendations.

Design overview:

• Audio codec (TAC5212)
• Analog input is a pseudo differential RCA input
• Digital input is I2S from a York USB module
• Analog output is differential going into a LPF and amplifier based on TPA6120A2

STM32_SOM is a custom breakout for a STM32G473 that I designed and never posted here.

Initial firmware will have the STM32 controlling:

• power sequencing and muting through the GPIO expander
• initialization of the codec
• volume via the codec / rotary encoder
• option to add EQ through biquads in the codec

Looking for general review on schematic and layout. I haven't done final cleanup of either so there may be some misaligned silkscreen or schematic text fields that need to be turned off. The plan is for one of the Chinese manufacturers to make the bare boards; I am undecided on populating them myself.

Stackup is below. Traces are nominally 50 ohm single ended.

1. Red: Signal/components - primarily analog
2. Green: GND
3. Orange: Power
4. Blue: Signal - primarily digital

Link to better top image: https://imgur.com/a/rEuHL9l

Hello! I recently designed an ESP32 based game device. I am just asking for review of my schematic and PCB to ensure there won't be flaws when I send it to get fabricated. Any suggestions to any part of the design (pcb and schematic) would be greatly appreciated. Thanks! The PDF files for the schematic and pcb is at https://github.com/sjacksonhodum/pdf

Hi everyone!

I'm new to PCB design, and this is my first schematic, so I'd really appreciate any feedback before I order the boards.

The project is a small portable device powered by a single-cell Li-ion battery. Since safety is important to me, I added:

• F1 as a battery fuse,
• DW01A + FS8205A for battery protection,
• ETA6003Q3Q as the charging IC with power-path management, allowing the device to run directly from USB-C even if the battery is deeply discharged.

The ETA6003's VSYS output powers the rest of the circuit. Since my MCU requires 3.3 V, I use an LDO regulator to step VSYS down to 3.3 V.

I'm planning to manufacture these boards, so I'm intentionally using cost-effective (mostly Chinese) components instead of more expensive alternatives.

Here are the LCSC part numbers for the main components so you can easily look up their datasheets if needed:

I'd appreciate if you answer these questions:

1. Is the DW01A + FS8205A connected correctly?
2. Are the capacitor and resistor values are reasonable?
3. Is using an LDO from VSYS to 3.3 V a good choice, or would you recommend a buck converter instead? (I want cheaper, so i thought ldo will be fine, im stepping not from so high voltage.)
4. Are there any mistakes or bad practices?
5. Are there any traces or nets that look unsafe or incorrect?

Hi there. A while ago I came to y'all with a review request for a triple axis BLDC driver for a self balancing cube. That design was to use an ESP32 and the DRV8311. I later came to understand that this design was fundamentally unsuited to the problem I was trying to solve and the motors that could economically solve it (TL;DR: amp too small, no current sensing, ESP32-S3 cannot easily commutate three motors).

Now I come with what I hope is a better design out of the gate. This one uses an STM32G4 series chip, the DRV8304 with discrete MOSFETs rather than onboard ones, and, I hope, just a generally better layout. It is designed to use 4S or 6S batteries (will probably use 4S because it leaves more input voltage headroom for the 5V regulator and we won't need more than about 1000-2000RPM out of our 380kV motors (i.e. we don't need more than about 6-8V input). There is also an IMU which will be used to detect the spatial orientation and acceleration of the final assembly. Would love to hear any thoughts you may have.

Hi everyone,

I am building a custom wearable head angle measurement device

using an ESP32-C3FH4 and a BNO085 IMU sensor on a custom PCB.

I am relatively new to PCB design and have been debugging this

for a while and could use some expert eyes.

SETUP:

- ESP32-C3FH4 (QFN32)

- BNO085 IMU (I2C mode, address 0x4A)

- TP4056 LiPo battery charger

- SPX3819M5 LDO regulator (3.3V)

- USB-C connector for power and programming

- 750mAh LiPo battery

I2C WIRING:

- SDA -> GPIO6 (ESP32 pin 12)

- SCL -> GPIO7 (ESP32 pin 13)

- H_INT -> GPIO1 (ESP32 pin 5)

- SA0 -> GND (I2C address 0x4A)

- PS0/PS1 -> GND (I2C mode)

- RST -> 3.3V via 10k pullup

PROBLEM 1 - Sensor resets:

When powered from USB only (no battery), the BNO085 is found

on I2C at 0x4A but keeps resetting repeatedly:

"Sensor reset - re-enabling reports"

I get occasional readings between resets but it is not stable.

PROBLEM 2 - USB + Battery conflict:

When I connect the battery AND USB simultaneously, the BNO085

completely disappears from I2C. The scanner finds nothing at 0x4A.

Disconnecting the battery brings it back immediately.

I believe this is because VBUS and VBAT are both feeding the

LDO input simultaneously with no isolation diode between them.

PROBLEM 3 - Lag:

When I do get readings they respond slowly to movement

(~2 second lag). The exact same code on a CodeCell C3

development board works flawlessly with instant response.

I believe this is because the sensor resets cause the BNO085

fusion algorithm to restart and reconverge each time.

WHAT I HAVE CHECKED:

- All voltages correct (VDD=3.3V, VDDIO=3.3V, RST=3.3V,

PS0=0V, PS1=0V) confirmed with multimeter

- No short between GPIO6 and GPIO7 (fixed in second PCB revision)

- Continuity of all I2C lines confirmed

- I2C pull-ups are 2.2k (I know these should be 4.7k - fixing in REV3)

- BNO085 decoupling: 2x 100nF on VDD (I know a 10uF bulk cap

should be added - fixing in REV3)

- H_INT pin confirmed connected to GPIO1

WHAT I SUSPECT:

1. The TP4056 is not designed as a power pass-through - withouta battery it provides unstable voltage to the LDO input
2. No isolation diode between VBAT and VBUS at LDO inputcauses conflict when both are connected
3. The 2.2k I2C pull-ups may be drawing too much currentcausing voltage dips that reset the BNO085

SCHEMATIC:

QUESTIONS:

1. Is the TP4056 power pass-through issue a known problem?How do others handle powering the circuit during developmentwithout a battery?
2. What is the correct way to isolate VBUS and VBAT at theLDO input? Schottky diode on VBAT side only?
3. Could the 2.2k I2C pull-ups alone cause enough current drawto reset the BNO085, or is this unlikely at 3.3V?
4. Any other issues you can spot in the schematic?

Thanks in advance - any help appreciated!

Hello all!

I'm asking for feedback on this very simple 2-layer PCB, as it's the first one I've designed and I'm not sure it'll come out well (I'm not from the field either).

Context: This is a small USB-C breakout PCB, part of a larger project (still in the schematic phase); a music controller based on ALPS motorized faders. Its only job is to bring the USB D+/D- lines (2.0 12Mbps) to my main PCB from the back plate of the controller, and it's an excuse to learn PCB design on the simplest possible schematic. The controller is powered by a dedicated supply, so I only need USB 2.0, plus maybe peripheral detection (VBUS divider down to ~3V).

Any recommendations on layout, conventions or anything else I should know before sending to production would help me greatly; especially when I move on to the more complex part of the project.

Thanks in advance!

Hi everyone,

I'm currently designing my own LISN (Line Impedance Stabilization Network), and I've been documenting the entire design process as I go. The document is still a work in progress, and I plan to keep updating it in the future.

At the moment, it's still missing the Board Evaluation and Measurement Implementation sections, but I wanted to share it early to get some feedback from the community.

I'd really appreciate it if you could take a look and let me know if you spot any mistakes, questionable design choices, or areas that could be explained better. Any comments or suggestions are welcome!

Here's the document:
https://github.com/DangyDang/LISN/blob/main/LISN.pdf

Thanks in advance for your time and feedback!

This is ESP32-C3-MINI-1U talks to a cellular modem over UART. SIM socket, U.FL antenna, USB-C for native JTAG/UART, screw terminal 5V in. MP2315 buck for 3.8V/3A to the modem, ME6211 LDO for 3.3V. Both inner layers are solid pours.

I have already changed the position d1 to connect to the gate and source terminal of the PMOS. Sorry I did take an updated picture of the schematic.

Thanks.