https://preview.redd.it/iba16expg4he1.png?width=2240&format=png&auto=webp&s=50b078de85581b6b1948317d4d64c8905602d178

https://preview.redd.it/kdxvgnaqg4he1.png?width=1452&format=png&auto=webp&s=39c9784878fcbaac18df4d642efd7b8230cc3578

https://preview.redd.it/ebmjbvmqg4he1.png?width=606&format=png&auto=webp&s=b928af90821778c39c282f963a906c50ec9aef15

Hey guys, newbie here!

I'm trying to build my first PCB and I'd like to hear your opinions on my schematic. The goal of this board is to implement a basic roulette. I'll flash the µC via SWD interface (using a pi pico with picoprobe firmware).

What I'm not sure about is:

- Boost DC-DC converter: did I do it right? What values should I choose for the resistors for the Low Battery Detection? I'll use two AA batteries to power up the system...should I use 3?
- SWD interface: is it okay as it is?
- Buzzer: I'm having trouble finding a suitable buzzer (from j-l-c as seller), do you have any suggestion?

I'm using tri-state buffers to drive the LEDs so that just one at a time is turned on, to implement the "spinning".

Thanks a lot in advance

https://preview.redd.it/i943mj4ac0he1.png?width=1368&format=png&auto=webp&s=c5a787b366761ac8cb67c7b19433ac9953eb29fa

https://preview.redd.it/efumv7yac0he1.png?width=864&format=png&auto=webp&s=8b8db27fda5d9d766bd57bd618f09981eea89167

https://preview.redd.it/zt2fp5yac0he1.png?width=1201&format=png&auto=webp&s=21098a7014e9762a13c4c753c66bfa72db021092

https://preview.redd.it/h4b4w5yac0he1.png?width=1380&format=png&auto=webp&s=5d58ba07f5fa2f4f26d6fa09702e50f92596f330

Hello all!

I am designing a device that can either act as an encoder reader or load cell amplifier. It then communicates this data via half duplex RS485 through a DB9 connector to a master device somewhere. I was hoping the hive mind of Reddit could review my work as this is the first implementation of a STM32 MCU I have ever designed!

As you can see it uses a STM32L432K MCU that will be programmed through a JTAG connector with a ST-LINK V2. Am I missing any peripherals to accomplish that?

The device is then either configured to listen to the encoder using the built in TIM2; or occasionally read the hx711 ADC/amp to obtain the load. The data is then sent from the STM MCU using USART1 through the DB9 connector using RS485 and put at the correct voltage via the MAX485 chip.

Please let me know if you think I am missing something before I start laying out the PCB!

Many thanks!

Felix

I'm an university student based in Bulgaria studying Computer systems and technology. I had an class where we were making a PCBs in Altium, and I came up with an idea, to monitor one design on diffrent layers to make PCBs. So I need a design that have an high temperature around 50 - 60 degrees. I searched online but didn't find anything good for this experiment.

https://preview.redd.it/1f7blex00wge1.png?width=1373&format=png&auto=webp&s=2384262c1c38dfa474fbbd6dccd417beec803e10

https://preview.redd.it/68yjpbq60wge1.png?width=1461&format=png&auto=webp&s=b220414aeab73e536b661c70be5bb8fc6a9f87dc

https://preview.redd.it/3ajgiyca0wge1.png?width=1134&format=png&auto=webp&s=6fcd5d4c6175b1038bc9a9991f13cadca89a529b

The following link has the schematic for the project: Schematic.pdf

This design utilizes a power ground, analog, ground and digital ground.

The buck-boost converter TPS552872RYQR, and 3.3V buck converter TPS62172DSG both use analog and power grounds.  Both datasheets say they should be isolated and meet at one point:

·        The VCC capacitor for the buck-boost converter

·        The PAD for the 3V3 buck converter

In the data sheet of the buck-boost converter, they use different layers for the analog and power grounds.

I also added a star point connection for all three grounds near the input voltage connections.

This is the main concern of my project, I am not completely confident in my design choices regarding the grounds.

Thank you all for your help and guidance!

Top Signal Layer

Inner Layer 1: GNDPWR

Inner Layer 2: VCC (Vin, Vout, 3V3, 3V0)

Inner Layer 3: GNDA

Inner Layer 4: GNDD

Bottom Signal Layer

Hi everyone,

I'm looking for a schematic review - this is an over-engineered power and battery supervisor/logger.

Thanks much for your time!

https://preview.redd.it/gawq38fh6sge1.png?width=2500&format=png&auto=webp&s=80b50270aadd28a9013c59118083b10262ba3dbf

Schematics

Top layer

Bottom layer

Top 3D

Bottom 3D

Top components

Bottom components

Hi, I've been wondering if its ok to make this kinds of trace intersections? Are there any negative effects, if any?

https://preview.redd.it/8z0480g47rge1.png?width=983&format=png&auto=webp&s=756a558741e4fc3a1d2f07736d5b9414567af741

Hello,

Sorry if my question seems to simple or on the contrary it doesn't exists for hobby / affordable for individual use but I'm quite a beginner in electronics and PCB design (not my field) 😅

Do you know if there are some tools that would allow me to simulate a PCB at an electronic level (so not just digital signals)? A bit like a SPICE simulator I suppose from what I saw but adding in the circuit the added equivalent resistance, capacitance and inductance of traces, components, connectors, ...etc of a routed board?

I've only done a very few PCBs so far and naively, so now after starting to read books / posts / reddit threads I'm quite curious to see actually (even if a simulation will still be different than reality) what are the effects of decoupling capacitors (by their presence or not, distance of ICs, value compared to the frequency of the signals used in the circuit, ...etc), ground planes (same thing, presence or not, layer where its placed, ...etc), impedence matching, ...etc

Being able to simulate this from a PCB editor that offers these functions would be nice because I could tweak easily one thing at a time and observe the result but if it's not really possible I suppose I suppose it could also be a good occasion for me to train making PCBs and investing in a good oscilloscope (as well as learning how to use one properly).

I suppose also I could try to recreate myself small circuits parts in a simple simulator that corresponds to the characteristics of a small PCB by adding discrete resistors, capacitors and inductors but as I'm learning this I think there's a high error magin that I would be off in my calculations or forgets something so it would still be far away to reality 🤔

Hello everyone! I've designed and built two revisions of a PCB and the USB 3 is not working. Is there a simulation SW I can use to debug where the issue is and optimize my PCB Design? I suspect that it is a trace length mismatch and not an issue with the diff impedance, but a simulation SW would be sublime. Any help is appreciated!

Posts in other subreddits:

• https://old.reddit.com/r/CustomsBroker/comments/1ifhyhe/tariffs_officially_announced_starting_tuesday_25/

• https://old.reddit.com/r/Flipping/comments/1ig8o67/usa_eliminates_800_dutyfree_de_minimis_exemption/

Various related articles:

• https://www.reuters.com/business/trump-readies-order-steep-tariffs-goods-mexico-canada-china-2025-02-01/

• https://www.hklaw.com/en/insights/publications/2025/01/cbp-proposes-to-modify-the-de-minimis-exemption

• https://www.cbp.gov/newsroom/national-media-release/cbp-proposes-new-rule-strengthen-enforcement-and-limit-duty

• https://www.whitehouse.gov/presidential-actions/2025/01/america-first-trade-policy/

Various business tariff webpages. Some of this information might be out of date per recent events.

• https://jlcpcb.com/help/article/Customs,-Duties-and-Taxes

• https://www.digikey.com/en/resources/tariff-resources

• https://www.mouser.com/section-301-tariff-updates/

• https://my.arrow.com/more/tariff-information-on-myarrow/

• https://www.jameco.com/Jameco/PressRoom/tariff-fee-reduction.html

• https://www.amazon.com/gp/help/customer/display.html?nodeId=G26L6NHEDGERVR8W

This is my first schematic/PCB. It's a keyboard with 3 Hall effect sensor keys, read via a multiplexer by a Teensy 4.1. Initial schematic review at PJRC was here. I think I've incorporated their suggestions, but they haven't reviewed the PCB.

• Schematic
• 2D PCB front
• 2D PCB back
• KiCad project

Notes:

• The huge 3 amp linear regulator (AMS1085CM-3.3) is overkill for a 3 key board. However, I plan to expand from 3 to 192 keys later, and each GH39FKSW Hall sensor draws up to 9mA, so 1.7A might be drawn from the sensors alone.
• The Teensy is powered by the external 5V instead of USB. See the PJRC forum link for why.
• U1/U2 are female sockets that the Teensy (U0) pins plug into. What's the best way to express this? On the schematic, I linked the Teensy symbol to the sockets using wires, but it's hard to read. Whereas on the PCB, I omitted the Teensy and only include the sockets, since the PCB maker will only provide the sockets.

EDIT: Revised images based on feedback from u/janoc.

• Schematic
• 2D PCB front
• 2D PCB front, zoomed in to switching regulator section
• 2D PCB back
• 3D PCB front
• 3D PCB back

Well, Im trying to make a PCB using dry film and a copper/fenol plate, It all goes well except in the development, as some tracks get dissolved easily and some other take way longer to, I suspect its related to the UV leds, as they tend to focus light in front of them, is there any way to improve the light dispersion on the box? My arrangment is a foiled cardboard box with 6 5mm UV leds soldered in a 4×3 board.

I keep my Pioneer A50 audio digital amplifier in a cabinet. I have to leave the cabinet doors open whenever I want to use its remote control. So I considered building an IR extender board connecting to the CONTROL-IN port on the back panel.

I breadboarded and tested it and it works as intended. Now, I have laid out the artwork and I would be happy if you could review it. Especially I am not sure I got the grounding right. This is the first time I have done the artwork properly by myself.

You can check the full schematics of the A50 Amplifier here, but I have included a capture of the most relevant section for ease of reference. Moreover, the USB power filter was shamelessly copied from online (I cannot paste the link because of subreddit rules), but I tried to understand its behavior as much as I could and documented it as notes to the schematics.

I posted a question about the purpose of the capacitors on the ground side to stack-exchange that was answered here.

Finally, here you can find a blog post of somebody explaining more about the CONTROL-IN/OUT functions of Pioneer devices.

EDIT 1:

• I have already noticed that the D2 diode is reversed in the PCB

EDIT 2:

• Increased size of pad cross pattern
• Added date to silkscreen
• R1 and R2 to 5.1kOhm

Schematics

3D view top

2D view bottom

2D view both

3D view top

3D view bottom

BOM

Pioneer A50 Amplifier - CONTROL-IN/OUT section

Hello!

This is the first PCB I've ever made and it is designed as an EV ECU. Would also love some feedback on the general layout of the schematics/usage of Altium features.

Thanks!

https://preview.redd.it/c2u83vc0udge1.png?width=1146&format=png&auto=webp&s=65d896c2cde0b024c114c63a5f55574ce72505f6

Schematic: IOs

Schematic: MCU Power

Schematic: Connectors

Schematic: Power

Schematic: ICs

2D: Layer 1

2D: Layer 4

2D: Layer 2

3D: Top

3D: Bottom

I am working on a project that uses a LED panel with HUB75 as a screen controlled by an ESP32 and I wanted to take the opportunity to learn how to desing PCBs. Its a simple design just to learn the basics and to avoid using a perfboard.

Any tips and advice is appreciated.

Traces are 0.6 mm except the 5V one that is 1 mm.

https://preview.redd.it/pg9zukie5dge1.png?width=541&format=png&auto=webp&s=0b78683820e08f7510f294c2ac655168dd2a9e7d