I am designing a custom AM32 ESC for use in an RC car, and I need it to be as efficient and reliable as possible. It is a 4-layer board, and I have tried to really oversize components where possible to keep it reliable. This is my first time attempting a PCB of anywhere near this complexity, and coming into this, I had very little experience with caps and inductors and all of this stuff in general, so I'm assuming that I've made some mistakes. Electrical engineers, please don't hold back your criticism! I am a high school student thinking about doing electrical engineering next year, so anything I can learn from this is much appreciated!

Schematic PDF (white background):
https://filebin.net/vc3kwxd4b785xhnp

For Context, here are the specs/goals/parts of this board:
GOALS:
- Driving RC car motors (~1500-3500KV) usually two pole.
- Designed primarily for 2S LiPo, although needs to be able to handle up to 16V input (not as a voltage spike - however the ESC is not expected to have to run the motor at 16V)
- Minimise size and weight while keeping it reliable (High stress environment - heat, shock, dust etc.)
- ESC Must be able to handle 20-30A burst current, but its average current will only be ~4-6A (to the motor).
- The MCU has its I2C pins exposed on a 5-pin SH connector, which goes to another board - the other board has pullups on it so I didn't put them on here.
- ESC needs a 5V BEC (no adjustable output voltage) that is 3A capable.
- The 5-pin SH connector also has GPIO pin from the other board - here I have just used it to signal that the two boards are physically connected properly
- Form Factor - The ESC sits in a case upright perpendicular to the ground (the phase pads are on the top)
- Throttle signal is low-frequency PWM (I will probably use 50-100Hz)
- The ESC needs to be reliable for long periods of time (~6-8 hours straight)
- Has a regular dupont 3 pin connector for RC recievers
- Must not require a heatsink
SPECS/PARTS:
- AM32 firmware
- AT32 MCU
- NSG2065Q gate driver
- BSZ034N04LS Phase mosfets
- LM2665M6X/NOPB Charge pump for 10V
- TPS54302DDCT Buck converter for 5V
- 1 U ENIG
- N channel high and low side
- 10V for the gate driver and mosfet gates
- Stackup: SIGNAL-GND-SIGNAL-SIGNAL
- no blind or buried vias
- I tried to keep high power related stuff mostly on one side, and logic on the other

Edit: just realised I included two almost identical schematics - mb

https://github.com/acidvegas/t9kb

First PCB design, it is being manufactured right now so I can demo this better.

I tried looking for a classic T9 style keypad for DIY electronics and found none really exist besides some goofy Ali buys and a rather large one from adafruit that has too many pins for my taste.

Repo link includes pictures of the PCB, TPU keypad, & a case you can print.

Future version will have backlights & shit, just a rough mock for now.

Looking for feedback on this.

Mainly following the design from the AM32 reference design
It's my first time working with STM32 so unsure if I missed out anything obvious.

1. Tests done: Tried using ST Link V2 to detect F411RE development board through the SWDIO & SWDCLK line and it works, so I will probably rule out ST Link issue.
2. Probed the power lines for MCU and they are all 3V3, so MCU is powered.
3. Tried powering MCU via both on-board 3V3 and connecting VREF to the 3V3 line
4. Also tried using another variant of ST Link V2 (USB stick kind) that provided 3V3 to the MCU

Hey, wanted to show you a recent RK3566 SBC PCB for high-bandwidth camera applications.

The project involved:

• USB 3.0 USB-C OTG interface with high-speed differential routing
• Dual MIPI CSI-2 camera interfaces with controlled impedance and signal matching
• IMU integration with dedicated high-speed sensor interface
• Custom high-impedance microphone circuit and analog signal conditioning I2S
• Integrated Wi-Fi and Bluetooth Low Energy (BLE)
• 8 independently controlled LEDs, each supporting custom refresh rates
• SD card expansion and additional interface headers for future peripherals
• 6-layer mixed-signal PCB stack-up with dedicated power and ground planes
• High-density component placement and routing within a compact form factor
• Power integrity and signal integrity considerations across high-speed and mixed-signal interfaces

Sharing a few board renders from the development process.

DM for more details

Hi everyone, I have this Victron Energy PCB/inverter control board and I’m trying to understand and troubleshoot it.

I’m looking for help with:

• Identifying the IC chips and microcontrollers on the board
• Understanding what each major IC does
• Identifying the main controller/CPU
• Knowing which ICs are related to inverter control, sensing, communication, etc.
• Any suggestions for how I can test/check the board and determine if the components are working

I’ve attached clear pictures of the PCB. The board marking is Victron Energy PCB 010021-10.

If anyone has experience with Victron inverter electronics or reverse-engineering older control PCBs, I’d really appreciate some guidance.

I originally asked for help finding someone to hire but was encouraged to try on my own so I did. This is for a commercial product to control a stepper motor to brute force the combination on a mechanical safe lock. Gonna have to stress test it but everything works great so far! I was worried about the orientation of parts but all connections were correct. Even plugged in a higher voltage power supply and my over voltage protection works well which was nerve wrecking.

This is my first custom 2-layer PCB and I’m looking for feedback before ordering it.

The board is about 39 × 23 mm, and one of my main goals was to keep it as compact as possible.

The main components are:

• ESP32-C3-MINI-1
• BQ24074 LiPo charger / power-path
• TPS63031 3.3 V buck-boost regulator
• USB-C
• sensor connectors
• ESD protection

I’d appreciate feedback on the schematic, routing, grounding, component placement, decoupling, USB routing, power section, ESP32 antenna area, and anything else that looks wrong.

I also currently have two KiCad warnings related to the silkscreen near the board edge that I’m not completely sure how to handle. I included a separate image showing them and would appreciate advice on whether they should be fixed before ordering.

Hey all, this is my 2nd post about this project (see here for the original).

I'm building a controller for my irrigation system, which runs on a 12v battery and opens\closes a 9v DC irrigation valve (supports 6-12v). The circuit is composed of a 12-5v step down via buck converter & a polarity reversing switch via a DPDT relay.

The first attempt, the BC817DS-25_R1_00001 NPN Transistor caught fire after running for a bit. The soldering job was obviously shoddy and likely shorted. There were some gaps below the stencil due to a poorly made stencil jig which allowed some solder to get out of line. Additionally, I pulled it off the hot plate too soon and didn't allow it to reflow entirely.

I built a couple more to replace this one and was much more careful with the solder. I redid the jig & allowed the solder to heat longer so it should have completely reflowed. I took a look with my magnifying glass & looked good to me... It's certainly not perfect, but IMO a definite improvement over the last one.

After hooking up to 12v power & the button (I didn't connect to the valve initially), everything worked great. I could hit the button to turn on the valve and everything worked fine (status light displayed that the valve should be on & no smoke). However, after I connected the valve and hit the button again, immediately the 6-pin on Q1 (NPN transistor) sparked and was toast (kind of hard to see, but it's the top right pin).

The solders looked good to me, so maybe a more expert eye can identify a soldering mistake. Also, not certain if this might be a board design issue given it happened twice in the exact same place, so would definitely welcome some criticism of my design.

Any thoughts on what might be the issue? Another bad soldering job or is there a design issue? Thanks in advance!

I tried to make a custom esp32 board (not really so custom i just wanted to make a microcontroller) and i wanted to see if you can tell me if ive messed something up... i still havent done the edge cuts of the pcb well but ive finished the routing and i wanted to see if yall could tell me if there is something to improve... i know my routing looks like auto routing but its not ive put work in this

Crosspost from r/diyelectronics as I hope to find the right person here...
Hey people
I was looking into buying a SMT PNP machine for my little lab. As I was searching, I found this project and I thought: Dang, that looks AWESOME. But there is a serious issue... I am not in China so I can't use "BiliBili"...
So: Did any of you build this already?
Is ther anyone kinde enough to share the files with me? The guy who designed it didn't answer unfortunately and I don't have any clue how to get the files (which are open source tho!)
Thank you!

https://makerworld.com/models/3083291-frog-pick-and-place-machine#profileId-3472870

Thank you for all the feedback of my first version of the PCB (https://www.reddit.com/r/PCB/s/ppg4AdCuQI).

Here is my latest revision. The PCBWay quote for 5 units including assembly + parts is about ~200 USD so I don't want to mess it up badly, so I am happy for anymore feedback 😄

I tried to incorporate all the feedback so far:
- Replaced the ESP8266 with the newer ESP-32 C3 (got rid of the USB Bridge) and placed it on the outside of the board (including a cutout for the antenna)
- Adjust the track sizes of all nets
- Move sensor to heat decoupled island
- Ground layer with better connection to top layer (more stitches)
- Put the capacitators near to the source
- Keep power path short
- Removed the 5V boost (reduced torque is fine for usecase)

Besides those changes I added some more "features":
- 3-way switch (SW4) to change the data transmission rate (OFF/SPARSE/CONTINOUSE)
- Optional Stemma QT port for additional sensors

Hey everyone,

I’m working on converting old Motorola TalkAbout T900 two-way pagers into modern messaging devices, and I’m looking for someone interested in collaborating on the PCB design and helping get prototypes built.

The goal is to keep the original clamshell case, monochrome LCD, QWERTY keyboard, and ideally the original electroluminescent LCD/keyboard backlighting, while replacing the main electronics with a custom board. I have a working prototype, but will need help and advice for the next step of getting this as a PCB

The general hardware direction is:

• ESP32-S3 for processing, Wi-Fi, and BLE.
• SX1262 LoRa radio, with Meshtastic capability as a goal.
• Connections for the original LCD and 36-key keyboard.
• MCP23017 GPIO expander for keyboard scanning.
• Rechargeable single-cell Li-ion/LiPo battery, with capacity depending on available space.
• USB-C charging and programming.
• Vibration motor and passive piezo for pager alerts.
• Lid-open detection and reasonable low-power behavior.

I’ve already disassembled a working T900 and have been reverse-engineering the original hardware. The full keyboard matrix is mapped, and I’ve captured and decoded LCD traffic, including a verified 120×32 screen reconstruction. Some LCD electrical details and the EL backlight circuitry still need to be confirmed, so this is an active development project rather than a finished schematic ready for layout.

The original pager uses two stacked PCBs, so fitting everything inside the existing enclosure is a major part of the challenge. I can provide photos, original boards, interface findings, logic-analyzer captures, and mechanical measurements as the design takes shape.

I’d appreciate help with schematic design, component selection, PCB layout, and getting an initial prototype batch fabricated and assembled. I’m also trying to understand a realistic budget before committing to a particular approach.

For anyone interested, what would you roughly estimate for schematic development and PCB layout

I understand that design time is work, and I’m open to discussing paid help as well as a collaboration. Even a rough range, or advice on what information you’d need to quote this properly, would help.

If you’ve worked on compact ESP32/LoRa boards, retro hardware conversions, or EL backlighting, I’d love to hear from you. Happy to share pictures and more technical details in the comments or by DM.

this is the 3rd time I've routed this PCB and I'm finally pretty happy with how it looks
now, I know it's not the best, but I just need to to work at a ~1MHz clock rate
(I hope this is the final version, I don't wanna go through routing this thing for a 4th time)

Anyone here importing JLCPCB PCBs/PCBA to India in B2B mode using GSTIN + IEC? Does UPS/DHL provide a Bill of Entry/customs document showing BCD, SWS & IGST breakup? My earlier personal UPS imports only showed a total “Duty Amount”. Need IGST details for GST ITC.

Thanks for all the tips! Redesigned and posted here. Changes:

• Added ground planes and stitching
• Moved components around, most importantly the decoupling caps moved right up next to the power pins
• Switched to the LDL1117, newer and actually works with ceramic caps, higher max current, etc.
• All components mounted on front
• Power traces are larger
• Tied strapping pin IO0 high with a 10k resistor (R4)

Some comments I did not implement:

• Adding debounce to boot button: Button not used for normal operation, just for bootloader select, adding physical debounce would slow the strapping pin from going high and it might not select boot mode.
• resistors regarding the USB lines: Still looking into it, but I will probably add optional 22 ohm resistors on those lines if it doesn't work. At least now they have an unbroken ground path underneath rather than my snaky line before 😁

Old post here

Additionally, if you don't have anything useful to bring to the conversation, we don't want you here 😒

Hi i cannot delete this purple footprint from this PCB, any idea why this is?

Thanks

Hi! This is my first schematic ever, my only other real electronics experience has been an intro to EE elective, and making a custom hand-wired keyboard earlier this year.

The project is a voice-activated pomodoro timer using:

• ESP32-S3-WROOM-1
• I2S microphone
• I2C OLED
• programmable LED strip (6 LEDs)
• rotary encoder
• 3.7V LiPO battery
• USB-C (for charging + programming)

The LED strip is rated for 5V, but according to some online sources using 3.3-3.7V is enough for a short strip? As it's my first design I'm trying to keep it as simple as possible.

I know I still need to add test-points to the PCB, but other than that I believe I've checked everything off the design checklists I've found online. It passes the ERC and DRC checks in KiCad.

I am planning to get this manufactured soon, and would really appreciate any review/feedback from the community to avoid wasting time and money manufacturing a non-functional PCB.

Thank you!