You must be logged in to reply.

Page 1 of 3 out of 26 messages.

Peer Review Of PCB design

Posted 3yr ago
by Gismofx | Senior | 1,322 exp
Posted 3yr ago
by Gismofx | Senior | 1,322 exp
I have designed a PCB with KiCAD and am ready to produce it, but would like some feedback before I have it made. I've tried my best to follow some best practices, but it's my first one!

Is this a good place, or is there a place for peer review PCB layout/design? If so, what files are needed for review? Schematic and screenshots of PCB?

Thanks.
Reply #1 — Posted 3yr ago
by Mr. John Smith | Legend | 42,263 exp
Reply #1 — Posted 3yr ago
by Mr. John Smith | Legend | 42,263 exp
That would be an off topic discussion. Are you using a GHI product in the design?
Reply #2 — Posted 2yr ago
by Gismofx | Senior | 1,322 exp
Reply #2 — Posted 2yr ago
by Gismofx | Senior | 1,322 exp
Of course...I'm plugging a GHI board into this PCB.
Reply #3 — Posted 2yr ago
by ianlee74 | Superhuman | 127,688 exp
Reply #3 — Posted 2yr ago
by ianlee74 | Superhuman | 127,688 exp
Post the design files and those that want to chime in will.
Reply #4 — Posted 2yr ago
by hagster | Hero | 18,264 exp
Reply #4 — Posted 2yr ago
by hagster | Hero | 18,264 exp
To check your gerber output files there are a number of free tools.

Gerbv works for me.

But the best way i know of is to use the PCB checker on Eurocircuits. This will check all the spacings, thru hole platings etc etc. I can almost garantee it will find something you didnt notice. Fix all the errors in your design and check again. Its free and you can buy from someone else if you prefer, but the tool is excellent.
Reply #5 — Posted 2yr ago
by Dave McLaughlin | Legend | 58,471 exp
Reply #5 — Posted 2yr ago
by Dave McLaughlin | Legend | 58,471 exp
Post the images of the PCB of decent size (2 x should be enough) and a PDF of the schematic somewhere and link them here and we will have a look. A few have done this before and we've spotted issues that helped them.
Reply #6 — Posted 2yr ago (modified)
by Gismofx | Senior | 1,322 exp
Reply #6 — Posted 2yr ago (modified)
by Gismofx | Senior | 1,322 exp
I'm using a CERB40II for this board, but it's rendered at a DIP40 chip. I've attached some screenshots of the PCB and included a PDF of the schematic. I'm using some optoisolators for pulsed inputs;The Tach IN is a 12v square wave signal, the speed signal is an open collector signal/sensor. The GLCD display and eeprom are SPI on SPI1. The temp sensor is a voltage divider on analog input, and the rotary encoder and push button are hardware debounced user inputs.

I'm using a 12v input to get 3.3 volts via an MCP16301 using the diagram on page 27. I've tried to layout the setup like they describe, but also would like confirmation that I'm using this part correctly as well.

Schematic: https://dl.dropboxusercontent.com/u/10786391/MotoGaugePCB%20v0.0.pdf

http://ww1.microchip.com/downloads/en/DeviceDoc/20005004D.pdf - page 27
Reply #7 — Posted 2yr ago
by Mr. John Smith | Legend | 42,263 exp
Reply #7 — Posted 2yr ago
by Mr. John Smith | Legend | 42,263 exp
@Gismofx - Are you going to post the artwork for the copper layers as well?
Reply #8 — Posted 2yr ago
by Dave McLaughlin | Legend | 58,471 exp
Reply #8 — Posted 2yr ago
by Dave McLaughlin | Legend | 58,471 exp
Strange PCB software as I don't see any pads for the 40 pin device on the underside of the board.

Anyway, a few things to think about.

Power rails are too thin. You really want to try and use heavier tracks for carrying power. On 2 layer designs and depending on the needs of the devices, I run 40 or 60 mil power rails for both GROUND and VCC (3.3, 5.0 etc)

Add a decoupling cap (0.1uF) next to U1

I can't see any tracks from from one side of L1. Keep these are short as possible and heavier (same as the power rails) between the inductor and the MCP16301.

I assume this is for a motorbike so there is no radio to worry about causing interference to. If so you need to add a filter on the input as the power rails could potentially generate a lot of EMC. Murata do some very nice automotive spec inlet filters for this purpose. Using a spectrum analyser and some EMC test kit I saw a huge drop in the transmitted signals on the power rails. All my designs now include these Smiley

What is the reason for the 10K pull up and 10K pull down on the ENC inputs? With no signal on these, the voltage on the input will be around 1.65V. Is there a reason for this? You really only need one of the other depending on how the encoder works.
Reply #9 — Posted 2yr ago
by Gismofx | Senior | 1,322 exp
Reply #9 — Posted 2yr ago
by Gismofx | Senior | 1,322 exp

Page 1 of 3 out of 26 messages.

You must be logged in to reply.