How to make a schematic you can post.

When you submit a question on the forum you will usually need to add a schematic (circuit diagram).

The tutorial that follows will explain some ways to create a usful image; however lets start by explaining how to add the image to your post. Its easy.

Having saved the image all you need to do is

  • save it to your desktop, then click on "> Attachments and other optons" ...
  • "Attach" Browse ..
  • and select the image file.

DONT upload it to Dropbox, google drive, etc. and post a link.

If you follow these simple instructions the diagram or picture will be shown in your post - as the images below are in this tutorial.

Now lets create a schematic.

To begin you must know at least SOME of the standards and symbols you will need.

A great start is to watch this video.

After watching you could visit this site that has loads of information especially suitable for beginners; and in particular a really nice list of the most commonly used symbols

You can also learn a LOT by learning to read schematics others have made.

For more experienced users this pdf document explains some of the more advanced features of schematics.

Lets get started making an image for a schematic you can post. Fritzing or a photo of your layout aren’t really satisfactory, especially if it has more than a few components.

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Many advocate starting by drawing on paper and submitting an image. Here is a typical example. Its readable.

However there are disadvantages to this approach; if you don’t KNOW the right symbol you have no clue what to use to represent the component.

There are also some apps that are very easy to use for beginners and can make nice clear *standards-compliant schematics. The main purpose of this tutorial is to introduce you to just TWO that are particularly easy to use.

Both of these will give a useful introduction to more capable (and complicated) apps such as Autodesk Eagle.

* Standards compliant? There are currently TWO important (and different) standards - the ANSI/IEEE symbols used in America and Canada, and IEC60617 used in many other countries (eg UK & Europe) Of course they are different. It doesnt help that the standards bodies dont make them freely available.

The first I have used for many years is Diagram Designer - get it here. Here is an example of me using it to make a diagram.

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I start by placing my main component - such as the arduino. The standard symbol for complex circuits is a simple box. Then I add more components, the wires to connect them, and finally the labels.

Remember where you can INPUTS go to the left, OUTPUTS to the right, positive voltages to top and negative to bottom.

Its an old package and the libraries are very limited but does produce good clear diagrams.

TinyCAD (see reply #9) is ALMOST as easy to use, and has a lot more symbols; and lots of instruction files and videos, so you may wish to skip Diagram Designer and move straight to that.

For more complex circuits a web-based package "circuit-diagram" has a big library of components - including the arduino and rasperry pi modules, and produces nice diagrams.

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Components show values and optionally designators – eg VR1. To add random text you need to search for the “label” component.

The component shows pin numbers in their physical place on the module. This is NOT standards compliant for your diagram, (as in not always flowing left to right input -> output) but can be helpful when assembling the final circuit. Compare this diagram with the diagram (Fig4) above to see the difference. Its the SAME circuit.

To place the input (potentiometer VR1) at the left I've needed to run a wire across others. Notice that wires CROSSING dont have a dot, wires JOINING do.

More good resources:

Circuit symbols

Units & Symbols for Electrical & Electronic Engineers - Ebook covering all important standards

and of course wikipedia

ANSI Standard: https://www.noao.edu/ets/Mechanical/Policies/ANSI%20Y32.2-1975.pdf

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Your images are not being displayed. How big are they and how did you insert them ?

A recent change to forum functionality will insert images in you post automatically if you attach them to a post

Thanks.

A recent change to forum functionality

had me confused. Hope its all there now.

Sorry about that John.

There was some basic announcements in website and forum topics and hopefully people catch on to the picture fixes and other minor improvements that are ongoing.

Bob.

Thanks for sharing John.

From another thread I've seen recommendations for KiCADand EasyEDA. I'll try them out and post updates to this tutorial.

I’d like to congratulate the OP for following unwritten basic rules of schematic layout - even in the first pencil sketch !

Voltage rails descending from highest at the top of the page to the bottom, signal flow and inputs from left-to-right, minimal crossovers and spaghetti bundles.

Excellent.

It was helpful. thanks for sharing

Look at the physical map, and then look at your schematic diagram, very professional.

I’m still trying some other CAD/schematic apps I’ve seen recommended.

TinyCAD

This is an old package, and has a lot of old parts libraries (that you can delete if you wont use them) - eg VALVES. All the libraries that start sm are for surface mount components.

It is very simple to use and behaves consistently with other apps - eg the select, Ctrl-z undo , delete, Ctrl-C Ctrl-V all behave as expected. The diagrams it produces are clear and readable.

The libraries have a search function so adding general components is very easy, and component identifiers and values are easily changed and positioned. Its also easy to make new parts if you cant find a ready-made one.

A point to note is that if the component sidebar is not visible you need to turn on
Options- toolbars - Symbol

I like this, I’d recommend it for beginners as a good way to progress to a more modern and sophisticated app such as Eagle.

There is a very good (albeit dated) guide to using TinyCAD here - But DONT delete the default libraries and install the “Alt” ones.

If you need more symbols you can easily make your own, but there is also an extensive symbol repository where you can search and add symbols to your own “personal” libary and download it.

And finally - for TinyCAD - my own library of parts for the Arduino; some collected from other sources, some - the Micro Pro, ESP32 and NodeMCU 8266 - I made myself; attached to this reply. Enjoy.

arduinoTCLib.zip (16.2 KB)