Help with PCB design review - esp32-c3 with IMU ( first pcb project ) - Page 1
Forum section: electronics / general

author: concode
author_rank: Newbie
timestamp: June 14, 2025, 02:33:40 pm
content: Hello, I have designed a small PCB using EasyEDA that integrates an IMU with the ESP32-C3. For my design, I referenced the ESP32-C3-DevKit-Rust-1 (https://github.com/esp-rs/esp-rust-board/tree/v1.2) and made some modification ( add IMU, Rheostat for sensor connection ) to suit my application.This is my first attempt at designing a PCB, so I would greatly appreciate any advice or feedback.Project Details.- The board uses the ESP32-C3 as the main controller and includes an IMU sensor.- I have attached the schematic and PCB layout- My main concerns are whether the connections are correct and if there are any layout issues that could cause problems during operation.What I Have Checked:- I ran DRC in EasyEDA- I am trying to follow the reference design as closely as possible and the datasheet.I would appreciate it if you could point out any incorrect or illogical connections, as well as suggest improvements for layout or best practices for a stable design.Thank you very much for your time and support!

author: Doctorandus_P
author_rank: Super Contributor
timestamp: June 15, 2025, 05:15:50 am
content: I recommend you remove all the dashed lines. For some strange reason they have become very common in the last couple of years, while they add nothing useful to the schematic. Instead they clutter the paper canvas and they take up an disproportional amount of your time. It's (unfortunately) very common to redraw these things several times to make everything fit, and you have to do it again each time a modification is made to the schematic.And really, when you remove them, and leave a bit of whitespace around different sections instead, then this does the same job, and does it better.I do like the titles of the circuit sections, It's always one of the first things to look at when I see a new schematic. Making these titles a bit bigger (and / orBold) makes them stand out more. You also have more room to do this when you remove the dashed lines.

author: concode
author_rank: Newbie
timestamp: June 15, 2025, 06:04:12 am
content: Thanks for your suggestion, I've updated the dashed lines removed files.Could you please review the updated schematic and let me know if you notice any electrical mistakes or issues with the connections?Your feedback would be greatly appreciated.

author: pcprogrammer
author_rank: Super Contributor
timestamp: June 15, 2025, 07:12:17 am
content: By the looks of the schematic, you used EasyEDApro, and it is very hard to read with the label names obscured by the port symbols.Contrary to Doctorandus_P, I find the texts to indicate the different sections to distracting, and add little value because most are just repeating what the circuit already tells you what it does. Like the reset and boot buttons, it is clear that they are for reset and boot selection.Then there are the different ground symbols being used. The four different length lines symbol is normally used for actual earth ground, and not for signal ground. The other ground symbol you used is so unclear due to the text and symbol interfering with each other, that it is hard to determine what is what. Also best practice is to keep the ground signals pointed downwards, and the supply symbols pointed upwards.Further more, best practice in schematic drawing is to maintain signal flow from left to right. For this place the USB connector on the top left side of the schematic and have the power related parts near it going from left to right. So, USB connector, buck converter, battery charge circuit and on the right the battery connector. Use wires to connect the battery connector directly to the charge circuit.Try to minimize the use of port symbols and use direct wire connections as much as possible. If components are well placed it makes a schematic easier to read. Also make sure that texts are not overlapping any other text, symbol or wire. Hide double information too. For instance the +3V3 supply shows twice that it is for +3V3, making it cluttered and harder to read when the second text is partially overlapped by the symbol.Unfortunately the PCB PDF export of the pro version is not showing the actual layers, so can't do a good review and I don't have a gerber viewer at hand, so can't comment on the PCB.An option is to export the project and attach that here. Just add a .txt extension after the .epro extension to be able to upload it here. The export can be made with the file menu save as local option.

author: concode
author_rank: Newbie
timestamp: June 15, 2025, 12:04:23 pm
content: As your suggestion, I modified the schematics as much as I could.I removed unnecessary section texts and minimized the use of port symbols, replacing them with direct wire connections wherever possible.I also reorganized the schematic to follow a left-to-right signal flow, as you suggested.Overlapping texts and symbols have been adjusted for better readability.For the ground connections, I tried to follow your advice by using a single, standard GND symbol (downward triangle) throughout the schematic, but I’m still not entirely confident that I applied this correctly. If you notice any mistakes or have further advice regarding proper GND usage, I would greatly appreciate your input.I apologize for the previous file not accurately representing the actual design.This time, I have exported and attached the project file as you described and thanks for your suggestion

author: pcprogrammer
author_rank: Super Contributor
timestamp: June 15, 2025, 04:15:38 pm
content: I looked at the project in EasyEDA Pro and it still is a bit of a mess. Yes you improved things a bit, but there is room for much more improvement. I did a small bit for you as to show how it can look better.A lot of the devices/blocks/parts you used have name and pin number enabled and these show up shining through the symbol cluttering up the schematic. So I disabled this for some of the parts. Also cleaned up some of the schematic to make it better readable by joining supply and ground parts together. Like for the reset and boot switch. Also corrected, what I believe to be wrong with, the boot switch setup as you made it.The names of the port labels need to be dragged out of the symbol to make them readable. I did this near the ESP32 module. With a bit more planning of where to put the components on the schematic, more of these port labels can be replaced with wires. Another note about port labels, is that they provide information about a signal, like if it is an input, output or bidirectional. For, for instance, serial RX and TX you should use the correct port symbols to not confuse readers of the schematic.I spotted an error near the battery connector, that was not in your first setup. You forgot to connect the ground to the negative terminal of the connector.As to the ground symbol. I normally use the triangle with the name GND beneath it. It looks like the default on EasyEDA Pro is AGND, but this is just a label and can be changed. This label can be used to differentiate between different ground parts of a schematic, like for analog sections, but there still needs to be a connection somewhere on the schematic between these separate grounds. On the PCB these can be drawn as separate ground planes under the needed sections.In your design there is no real need for this, so you can change all the ground symbols to the triangle with GND as label.For the PCB you did a nice job of cramming it all onto a very small board, and I count on the software DRC checks that things are in order, as long as the schematic is correct, which at this point it ain't, so after finishing the schematic you have to check the PCB.To make it better and emit less EMI, I advise you to do a ground poor on the bottom layer. This is done with the copper area tool. (Dashed polygon in the menu bar)

author: concode
author_rank: Newbie
timestamp: June 16, 2025, 11:40:29 am
content: Thank you for your detailed feedback. I have updated the schematic and added a ground pour to the bottom layer as you suggested.Would it be even more beneficial to add a ground pour to the top layer as well? I have attached the modified schematic and PCB file with the bottom layer ground pour for your review.I have some mistakes, reattach a new file.

author: pcprogrammer
author_rank: Super Contributor
timestamp: June 16, 2025, 01:06:39 pm
content: A ground poor on the top plane won't be very helpful on your board. The plane is already filled with the pads for the components, leaving little room for a ground poor. It might allow for a better ground return path when stitching of top and bottom is done with vias.I usually order a small PCB only test batch and see if it works while placing components. For instance, only solder the MCU and see if it runs. If so add the sensor part and check if that works, etc.With cheap Chinese PCB manufacturers, for me at least, it is less than 5 euros for 5 boards of 100mm x 100mm, so not a big deal when there is a mistake in the design.

author: concode
author_rank: Newbie
timestamp: June 16, 2025, 01:40:17 pm
content: Thank you for your reply. I'll ordering a PCB, but I don't have experience with soldering tiny components.So, do you have any useful tips or tricks for hand-soldering SMD chips? The components I need to solder are very small and the pins are packed closely together, so I’m looking for advice on how to solder them cleanly without making mistakes. Any recommendations on using flux, choosing the right soldering iron tip, or techniques like drag soldering would be really helpful.I'm really thank you for your advice.

author: pcprogrammer
author_rank: Super Contributor
timestamp: June 16, 2025, 02:30:24 pm
content: Low temperature solder paste and hot air can be helpful, especially with the ESP32 chip. Also a good microscope to enlarge what you see is useful.I don't do SMD below 0805 as it is to hard for me at my age. (60+) For this I use a C245 soldering iron (clone) with either a knife tip or a chissel tip.Maybe look on the net for some good youtube tutorials on how to solder SMD

author: concode
author_rank: Newbie
timestamp: June 17, 2025, 12:53:59 am
content: Thank you so much for all your help and advice throughout this project. I’m 17 years old, and working on this has been a really valuable experience for me. I really appreciate the time you took to answer my questions and share your knowledge. Thanks again!