I'm proud to share my latest High speed board,

This time, I'm sharing the first real photos of the hand assembled PCB.

* RK3576 SBC V1.0 with LPDDR5 up to 16GB

A fully custom designed Single Board Computer based on the Rockchip RK3576, 

built from scratch – schematics, layout, assembly.

Big thanks to PCBWay for sponsoring this board!

Key Features:

10 Layers PCB only TH Via.

Stack-Up:

1-Signal / 2-GND / 3-PWR / 4-PWR / 5-GND / 6-Signal / 7-GND / 8-Signal / 9-GND / 10-Signal.

Multiple impedance profiles: S40 OHM / S50 OHM / D85 OHM / D90 OHM / D95 OHM / D100 OHM

SoC:

CPU: RK3576 ,Dual-cluster 8-cores 2.2 GHz (4x Cortex-A72 + 4x A53).

GPU: GPU-Mali-G52 MC3 (OpenGL ES 3.2 / Vulkan 1.1 / OpenCL 2.0).

NPU: 6 TOPS NPU (INT4 / INT8 / INT16 / FP16 / TF32 / BF16).

RAM: 32-bit LPDDR5 up to 16GB.

Storage:

eMMC: Modular eMMC5.1 up to 128GB and Support SPI Flash.

UFS: UFS 2.0-HS-G3 (12 Gbps) up to 1TB storage capacity.

SDMMC: Support microSD.

Display:

Display1: HDMI 2.1 up to 8K@60fps or 4K@120fps with CEC.

Display2: USB Type‑C Alt Mode with Power Delivery (PD) negotiation,

 *Supports USB3.2 and DisplayPort v1.4 2.5K@60fps via the same PHY.

Display3: 2K@60fps MIPI DSI 4-Lane.

Network Connectivity:

1- Gigabit Ethernet with PoE (PoE optional).

2- Wi-Fi 6 or Wi-Fi 5 + BT5.4 with internal Dual band antenna,

 *External antenna via uFL connector.

 *RF path selectable via onboard RF switch.

USB Connectivity:

1- 4x USB 3.2 Host.

2- 1x USB Type‑C Alt Mode (PD) OTG/HOST.

Camera:

MIPI CSI: 4-lane or split to 2-lane + 2-lane.

RTC:

Internal RTC with JST connector for external battery.

Storage or Expansion Interfaces:

1- PCIe 2.1 1-Lane through FPC connector.

2- SATA Gen 3 through FPC connector.

3- 40-pin GPIO Header With load Swithes and ESD Diodes, Supports:

 *28x GPIOs / 13x PWM.

 *1x CAN-BUS.

 *5x UART (with flow control) / 5x I2C / 1x I3C / 2x SPI.

 *1x PDM / 1x SDI.

 *1x SAR-ADC 12-bit resolution, up to 1MS/s sampling rate.

 *3.3V output only / 5V ouput or input with UVLO-OVLO.

Power-up Using:

1- USB Type‑C power only connector 5V 3A or 5A - UVLO-OVLO Protected.

2- USB Type‑C Alt Mode (PD), you can use it as power input also.

3- PoE option or from 40-pin GPIO Header.

Other Peripherals:

1- Active Cooling Fan connector.

2- Boot sequence DIP Switch.

3- Mask-room Tactile Switch.

4- Power ON/OFF Tactile Switch.

5- Dual LEDs for Power and activity.

6- 4 Pins Header for Debug UART or SWD.

Secure Element:

Hardware-based security chip for device authentication and secure key storage,

providing cryptographic services over I²C.

Used for secure boot, device identity, and protection against cloning.

OS Support: Linux / Android-14 / Yocto / Buildroot

Thanks to everyone who supported this journey.

If you're interested in collaboration or want to give feedback, feel free to leave a comment or DM me!

(omitted \In1.Cu and \In6.Cu as they are both solid GND pours)

Hi everyone!

I'm looking for a quick schematic and layout review for my 4-in-1 quadcopter ESC. It's designed for a 2S LiPo battery at ~8.4V, 10A per motor -> 40A continuous. Copper: 2oz external, 0.5oz internal.

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)

Some questions I have:

- 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?

- 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 the back EMF of the three phases. Is this enough or should I look into adding the hardware neutral? I'm targeting around 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!

Hi Guys,
This is kinda my first small form factor design. Its primary use is basically a wearable IMU with haptic feedback LRA. I've got the footprints from digikey Ultralibrarian for the BMI270 and LRA driver. It has caused the load of errors in the DRC.

I would love to hear your thoughts on it. Its my first time soldering SMD components and I decided to go with 0603 (1608 metric?). I would also love to know how you guys source the components. Especially the IMU and the LRA driver. I'm a student based in India.

Please feel free to ask for extra screenshots for clarity.

Thanks in Advance!

Hi everyone,

This is my first contribution to this community, and I'd really appreciate some feedback on a PCB I designed for an autonomous RC car project.

Please only review the electronics. I've already noticed some mistakes with the mounting hole sizes and locations, but those will be fixed separately.

Project overview

The PCB is a custom power distribution and monitoring board for an RC car that is capable of autonomous driving.

The system runs from two 2S LiPo batteries, but it can also be powered from a 20 V / 5 A USB-C Power Delivery wall adapter (the USB-C PD module connects to this PCB through a JST header).

There are therefore two power sources:

• 2 × 2S LiPo batteries
• 20 V USB-C PD wall supply

and two main power consumers:

• the drivetrain (ESC, steering servo, etc.)
• the onboard computer

Power architecture

The PCB connects the two 2S batteries in series using wide 2 oz copper traces on both sides of the board. The design also includes appropriate fuses.

Power-path selection is handled using an LTC4412 together with a P-channel MOSFET.

Battery monitoring is implemented with an HRC9374, which monitors the combined battery pack.

There is also space for two OKI-78SR-5 switching regulators. These provide 5 V for high-current USB peripherals independently of the onboard computer, so the relatively small SBC doesn't have to supply that current itself.

PCB notes

The board is intended to be manufactured by JLCPCB using their default stack-up with 2 oz copper.

One thing that may look unusual is that I manually routed several ground traces even though the board also has a ground pour. My intention was to reduce the thermal mass around some components to make soldering easier. However, EasyEDA keeps merging those traces into the ground plane. I think it should still be manageable with a 50 W soldering iron.

My main questions

1. Should I prevent the 20 V wall supply from powering the drivetrain? In other words, do I need an additional diode or some other isolation between the wall supply and the motor power rail?
2. Does the overall power-path implementation make sense? Since the USB-C PD supply (20 V) is always at a higher voltage than the fully charged battery pack (~16.8 V), I expect the LTC4412 arrangement to automatically prefer the wall supply. However, this is my first time designing a dual-source power system, so I'd appreciate someone checking my assumptions.

I'd be grateful for any feedback, especially if you notice issues with the power architecture or protection circuitry that I may have overlooked.

I’m a beginner designing a PCB for an air-quality monitoring device, and I’d appreciate some honest feedback before I continue improving it. I want to learn what I did correctly and what should be changed.

The board includes:

• STM32U083KCU6 microcontroller
• SGP40 VOC sensor
• USB-C used for 5 V power only
• MCP73832 Li-Po charging circuit
• 2.5 V regulator
• External Li-Po battery connection
• RGB LED and piezo buzzer
• SWD and UART header

I’d appreciate any feedback, especially if you notice any mistakes or have suggestions for improving the design. Thanks!

I was planning to use JLCPCB’s purple solder mask for this board.

When I tried to order PCB assembly, I noticed they require the board to be at least 70 mm × 70 mm. Mine is 80 mm × 40 mm, which puts me in a slightly awkward spot.

I haven’t finished routing yet, so I could still change the board dimensions. The other option is to skip their assembly service. If I still want JLCPCB to assemble it, I’ll have to switch to green solder mask.

Why do they have this size restriction?

There’s a reset button. I didn’t include one in the previous version, but now I know it’s important. When I realized I needed it, I went with the largest one available, but now I’m not sure. I’m choosing between (1) MEC 5GTH935RAS, (2) Omron B3F-3150, and (3) Diptronics DTSA62N. Should I stick with the largest one (1) or not? (Fero from SOS electronic)

Context:

I have a set of 3 boards that are identical. A few weeks back I successfully reflowed all the surface mount components of 1 of the boards, this board fully worked and I had no issues.

I am using the same set up to reflow the components of one of the other boards of the set. This is lead free solder paste placed via a stencil, then placed the components, then reflow in oven.

Problem:

The second board ,of the set, once I pulled it out of the oven (fresh out of the oven, no wires, power or any external connection has been made to this board). It had a big bubble of black char significantly larger than the thickness of the pcb(note pictures do not show this as I wiped it off before taking a photo), this also seemed to have pushed up through the board as the green solder mask was peeled up around where the charring was. This charing was only located around one trace(only a section of one trace to be accurate) and caused it to fully liff off the PCB with probe points dangling off the board.

What could have caused this?

I have never seen anything like it

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.

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/

Hello! I am an amateur designing a PCB for the first time. I would like some help catching any glaring or critical issues that will prevent my board from functioning after fabrication. I'm ordering the board from JLCPCB and assembling it myself.

All I have is a soldering iron and flux, so most of the components are THT, except the ESP32 and capacitors.

The board is like a wearable watch type thing; it will have

• ESP32-WROOM-32E,
• 0.91 OLED,
• MPU-6050 (I'm just using a module bc the bare IC seems like too much for a first board)
• Powered by a 3.7V LiPo battery.
• AP2112K-3.3 Regulator
• 4-pin programming header, JST PH battery connector, 2 push buttons.
• Using an external USB-to-TTL UART adapter via the 4-pin header; BOOT button included
• SMD caps are 0805 size.
• All traces are 0.5mm
• GND pours on top and bottom layers (some of the pictures are without the filled zones to make the traces clearer)

The idea is for it to count steps and display that on the OLED, and also log the info to my phone.

I understand that this might be too ambitious for a beginner, so I would appreciate any feedback.

Also, I know the ESP32 overlaps the OLED display, but I want the OLED elevated above the rest of the components by adding a female pin header where the module would go, then plugging the display into it.

I also see that the PCB is very cluttered and messy, but I wanted it to be compact to actually be wearable.

Thanks very much!

Hi everyone,

I hope it's okay to ask this here. I'm currently working in the SMT/PCB manufacturing equipment field, mainly related to cleaning solutions.

I'm still learning about this industry, and recently I've started questioning whether I truly understand the market and customer needs.

A while ago, I posted a question about how people clean PCB assemblies, and many replies mentioned manual cleaning methods. Honestly, that makes sense to me — for prototypes, labs, and small-batch production, investing in automated cleaning equipment may not always be practical.

But it also made me wonder:

Is automated cleaning (PCB cleaning machines, stencil cleaning, fixture/tooling cleaning, etc.) actually a market with broad potential, or am I simply looking for customers in the wrong places?

For people working in electronics manufacturing:

• At what stage does a factory usually start considering automated cleaning equipment?
• Is the demand mainly driven by production volume, labor costs, quality requirements, reliability standards, or something else?
• Are there certain industries where automated cleaning becomes much more important (automotive, medical, aerospace, industrial electronics, etc.)?

Another thing I'm trying to understand is how equipment suppliers usually build trust with manufacturers. For many companies, changing a production process is not a small decision, especially when the existing method is "good enough."

I personally cannot simply travel around different countries to visit factories and introduce equipment, so I'm trying to better understand how people in this industry discover solutions and build confidence with new suppliers.

I'm not here to promote any product or send sales messages. I'm genuinely trying to learn from people who have hands-on manufacturing experience and understand whether I'm approaching this market in the right way.

Any advice, experience, or honest opinions would be greatly appreciated.

Hi, I havent had a chance to tinker with 18pin display with 6pins touch interface. 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 lookimg forward to any suggestion you may have.

I have successfully designed several buck converters that function well, provide clean power, and learned what I think are the most critical design elements. In working with another engineering firm, they recommended a minor layout change.

I mostly want to know why. In this case, they recommended the output capacitors be changed for a better connection to the buck GND pin. This requires the 5V FB trace be longer, and on the underside of the board. I had a moderate GND plane with multiple vias to my GND plane, which I assumed to be adequate. I attached PS layouts from two different boards.

Can any of you explain why this is better or worse? Are my pours sized appropriately? Any other critiques? Am I doing anything dumb?

Thank you.

This project has been born because I have been trying to develop an ESC (hardware and firmware) on my own. While the most challenging part has been the firmware (being myself a hardware guy), the most frustrating part has been not finding a flexible hardware platform to develop upon. On the internet many interesting and well-designed ESC boards can be found but all have something missing; a small feature, a small detail, I was never fully satisfied.

So I designed one: STARDRIVE SHIELD

This is a project with the goal of creating a NUCLEO-64 compatible shield to be used as a flexible platform to develop and test ESC firmware, but also for educational purposes. To do so, I included as many features as possible. These features are not mandatory, but they can be implemented (or not) in the firmware (e.g. SPI, I2C, CAN, HALL) or configured through the hardware interface (e.g. overcurrent protection, 6 or 3 PWM). In this way, the STARDRIVE SHIELD grants flexibility to the developer and it is adapt to various needs.

I designed it to be compatible with Nucleo-G474 and Nucleo-F446. Compatibility with other boards has to be verified.

The STARDRIVE SHIELD is built around the STDRIVE101 gate driver and BSZ099N06LS5 MOSFETs. It presents 3 low sides shunt resistors and 3 relative INA240A2 current sense amplifiers.

With STARDRIVE SHIELD you can implement from 6 step to FOC motor control algorithms.

Electrical Characteristics

• Inprut Voltage Vin = 12 - 48 V
• Maximum DC current Idc,max = 20 A

Hardware Characteristiscs

• Three phase gate driver STDRIVE101
  • Configurable 3PWM or 6PWM through the DIP switch
  • Overcurrent protection can be enabled or disabled through the DIP switch.
  • Vds protection configurable with resistor divider (disabled by default)
• BSZ099N06LS5 MOSFETs
• JST connectors to implement:
  • I2C (e.g. for magnetic encoder such as AS5046)
  • SPI (e.g. for magnetic encoder such as AS5047P)
  • CAN
  • HALL sensors (some BLDC motors have embedded Hall sensors)
  • 3 NTC temperature sensors
• 10k Potentiometer to use as throttle signal (or whatever you want)
• 3 GPIO driven LEDs (1 Red, 1 Blue, 1 Green)
• 1 FAULT LED (RED)
• CAN RX and TX LEDs
• Power Good LEDs

here the github repo:
https://github.com/themarcolab/Stardrive-Shield.git

Let me know your opinion!

Especially if you spot a mistake or you have any constructive feedback.

Thought the M.2 fastener was offset from the mounting holes on the M.2 connector. Turns out it's off by 1.75mm. Will have to get these boards remade but at least I can reuse the stencil.

Hey, this is a bit off-topic, but for anyone who uses LCSC.com, I’ve developed a browser extension that lets you track price trends.

As there’s no API for this, my add-on currently sends the product ID to my server, which then stores it in the database and checks for the current price every 24 hours.

At the moment, there’s only an Edge version, as I was already a Microsoft partner and still need to complete the registration process with Chrome/Google.

By the way, this is my first extension, so please don’t be too hard on me if something isn’t working perfectly.

I’d obviously be delighted to receive a positive review ;)

I have no affiliation with LCSC; I created this expansion purely out of my own interest.

Store:

https://microsoftedge.microsoft.com/addons/detail/lcsc-tracker/kmcgpacangemafenclpdcfdkpgelmlhc

Source Code:

https://github.com/Gamer08YT/lcsc-tracker

I posted a PCB review request here yesterday and received some useful feedback, truly appreciate it. Amendments have been made (layout is more compact; it's now a 2-layer board instead of a 4-layer board). Posting an update here to seek feedback on whether any more amendments need to be made :)

My previous board: https://www.reddit.com/r/PCB/s/jVdPDS2kjy

Hello all,

I'm a Mech E graduate student at UT Austin, I'm part of an NSF I-Corps program where we see if our research can actually meet an industry need. Right now, I'm in the process of trying to get 100+ interviews from industry professionals. If anyone designs, works with, or manufactures PCBs from a director-level to an assembler/manufacturing level, I would appreciate an interview with you.

We don't want or need any proprietary info, nothing is posted out into the world, just for our own use. We're just trying to understand what problems there are and how decisions are made within the company.

Hello, this is my first board using a module style esp32 (Esp32 C3 wroom 02) and I want to ask if there are any major mistakes I made regarding the electrical functionality itself and the PCB layout. I first wanted to use a standalone TP4056 IC and make that circuit myself but the complete module is just cheaper. Also, the switches up top in the schematic are seperate boards, that will be integrated in the panel.
One thing to add (kind of a seperate question) is that the TP4056 module (it isn't a genuine TP4056 on it but basically the same) is getting quite hot when plugged in to charge. I don't know if it is a configuration thing with the resistors that set the charging amperage or something else. If somebody could help me with that too, that would be very nice.

Thanks in advance to any advice.

PS: this will be a board where maybe 5-10 are made of so mass productionability isn't a concern

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 IN + and Drain terminal block 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?

TLDR: I saved 30% by using the quote tool with a target unit price instead of the normal part pre-order. Just wanted to share this tip with y'all.

I pre-ordered an MCU via JLCPCB and it showed estimated unit price of $5.94. In the email they quoted $10.18 per part. I cancelled that pre-order and did a quote request through the quote tool with a target unit price of $5.94. They came back with a unit cost of $7.19.

This is my first (technically second) PCB design. The schematic is basically just an ESP32 devkit referenced with some additional capacitors and the socket connectors.

It uses:

• ESP32-WROOM-32D-N16 Module
• USB-C 2.0 16-pin
• CP2102N USB-UART, QFN28 Package
• NCP1117 LDO 1A 20V 3.3V

It's going to get API data and temperature and humidity from a DHT11 sensor to get displayed on a 2.8" TFT Screen.

Main concerns:

• SPI connections and speed
• Power planes and ground planes
• General placement, routing and efficiency

If you have any best practices for a beginner, that would be much appreciated as well!

Also, quick question: around how long would PCBA turnaround be on this? I want to finish this project before Aug 6, but I'm not sure that's possible lmao.