PCB common ground connection - what is the standard way to do it?

Thread Starter

mhasan

Joined Sep 7, 2021
2
Hi guys,
I am a software engineer, trying to do some electronics hooby work.
I am trying to build a controller circuit with Teensy 4.1 board and trying to design a professional looking PCB for the project.

My circuit design is very simple, I want to connect most of the Teensy 4.1 pin to a 40 pin strip header connector.
From there I can connect other components (I.e. switched and potntiometers). the design dilemma I am having while trying to drawing the schemetic for this iny project is, how to connect the ground of the teensy board to all the sswitches?

all the switched and potentiometer get connected to a common ground pin, but I am not sure how to make this connection cleaner?
What is the best way to desing these kind of common ground connction, where the ground is shared with 30+ seperate components?
I am doing the drawing usinf EasyEDA.

Thanks,
M
 

jiggermole

Joined Jul 29, 2016
48
Also a hobbyist here. Usually I apply a ground plane to my bottom layer. Sometimes to both the top and bottom layer. I use EagleCAD and I just make a polygon covering the whole board on the layer you want and make it the GND signal.
 

Thread Starter

mhasan

Joined Sep 7, 2021
2
Also a hobbyist here. Usually I apply a ground plane to my bottom layer. Sometimes to both the top and bottom layer. I use EagleCAD and I just make a polygon covering the whole board on the layer you want and make it the GND signal.
Thanks.
 

MrChips

Joined Oct 2, 2009
24,610
Assuming that every switch and sensor requires two connections, one of which being GND, I would use a dual row IDC ribbon cable. All of the pins of one row are connected to GND so that the ribbon cable supplies a pair of wires that go to each switch.

For powered sensors, e.g. potentiometers, that need three connections, I would use single 3-pin IDC connectors.

For digital inputs, e.g. switches, connect the grounds back to digital ground or supply GND.
For analog inputs, e.g. potentiometers, connect the grounds back to analog ground at the ADC.

Not every application needs a ground plane. Depending on the application, frequency of operation, and sensitivity to noise, you may be able do avoid using a ground plane.
 

dl324

Joined Mar 30, 2015
13,506
the design dilemma I am having while trying to drawing the schemetic for this iny project is, how to connect the ground of the teensy board to all the sswitches?
If you don't have analog and digital circuits on the board or high currents involved, it's pretty much a don't care. Just make sure you have sufficient decoupling caps on any IC's.

If you have analog and digital circuitry on the same board, conventional wisdom is to connect the digital and analog grounds in one place. Currents involved also play a role.
 

MrChips

Joined Oct 2, 2009
24,610
When laying a PCB I avoid connecting pads in a line (daisy chain) as shown on pattern A.
I prefer to offset the trace from the pads as in pattern B. This allows you to be able to isolate a pin by cutting the connection to the pad in the event that you need to make some corrections or do some debugging.

PCB routing through pads.jpg
 
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