Engineers make a schematic to explain their circuits.
One time I was looking for a non-tourist pub in Japan. I asked someone for help. She said, “I’m sorry, but I do not speak good English. I will bring my friend, and she will draw you a map.” (Exact quote!) The map her friend drew, gave directions to a bar with a “Neon Yellow Sing.” She meant “sign.”
The map was the method we used to communicate with each other, even though we didn’t both speak English. With this crude but useful map, I could find my next
drinking place destination.
Schematics are the same as this map. Even if you don’t speak the same language, you can communicate how a circuit works when you make a schematic.
Use one of these five tools, when you need to a document a circuit or when you need to ask for help.
For years, EAGLE has been the go-to standard for creating open source hardware schematics. The free non-commercial version has many powerful features enabled. The licensing compared to other professional options is inexpensive. There are native versions for Windows, Mac, and Linux. Both Arduino (#TeamArduinoCC) and Adafruit use EAGLE extensively for their design work. However, all of these positives come with a drawback.
The software has a steep learning curve. The most prominent mistake I see new users make is trying to treat it as a vector editing program like Illustrator or Inkscape. Instead, you need to remember it is a command-based CAD system.
Which is why I’ve written EAGLE tutorials on how to copy and paste, enabling ground planes and others.
This open source project has grown in popularity. The steep learning curve has kept some away. Popular engineers like Chris Gammell of Contextual Electronics has even created a thriving forum. The software is also cross-platform with native versions on Windows, OSX, and Linux. The Mac version isn’t as “Mac-like” as some would prefer. For example, the zoom-to-scroll has some strange acceleration. However, this is just part of the learning curve. You will get used to how KiCad’s various pieces operate.
Other than closed source vs. open source, the operational model differs from EAGLE. KiCad isn’t a monolithic application. The schematic editor and circuit board editor are entirely separate. So are the schematic symbol editor and PCB footprint generator, for that matter. The downside to this approach is that keyboard shortcuts and menu locations for items are not the same across the suite. At first, this can be off-putting. In time though, you learn everything’s place.
To be honest, it took me about three projects before I got comfortable with KiCad. Now I’m about to capture a schematic quickly, create custom parts, and layout a board without much issue. One recommendation I would make, consider using the nightly builds. As of this writing, the 4.0 branch is stable. While stable, it is very behind in many areas, compared to the nightly builds.
Even though the real reason to use iCircuit is to simulate a circuit, I find it a great option to make a schematic quickly. For one, you won’t get lost in a sea of part numbers. Instead of a million transistors, just select “NPN BJT” or “N-Channel MOSFET.”
The touch inspired controls translate well into a mouse environment. So there is almost no learning curve when you draw a schematic. When you are ready to publish a schematic, it generates a nice clean PDF, PNG or SVG.
The downside, you need to be on iOS, Android, OS X or Windows 8.
How about a schematic editor that is easy to use, free, and doesn’t require any software installation? That’s upverter.com.
Think of it as GitHub for Schematics. You can make a schematic quickly, invite others to collaborate, and there is a project browser like GitHub.
You need to be careful when signing up because there are steeply priced monthly versions. Those are great for professional users or commercial projects.
If you are a student or don’t mind your non-commercial projects being public, checkout upverter community edition. Which is free.
5. Paper and Pencil
When a 100% perfect schematic is only your head, it is 100% useless to anyone trying to help you. In other words, making a schematic that is scribbled out on paper is better than not providing one at all.
This is a good option when you aren’t sure what schematic symbols to use or you need to get an answer before you can learn a new tool.
Just make sure you take care to properly scan in your masterpiece before posting it to a forum. For example, limit the width of your scan to 1000px or 72dpi. If your PNG is 1MB, it is way(!) too big.
what would you say about TinkerCAD.com ?
they have a circuit section, formerly known as circuits.io
I would say TinkerCAD is a web-based 3D modeling program. I have never really used it.
While not obvious, the schematic drawing tools in LTSpice are moderately easy to use, support Windows, Linux(under Wine) and Mac. There is an export to a raster graphics format and I have used it for quickly putting a simple schematic in a document.
I draw diagrams using InkScape, a vector drawing package. I’ve drawn my own symbols and with the grid and snap turned on, wires and pins connect automatically. It gives me infinite flexibility in designing my own symbols and controlling every other detail, but requires that I do some things manually. I have to individually position text for each component value, for example. Anyone who is interested can find the template file I use here: https://hackaday.io/project/2514-circuit-schematic-drafting-system
The problem I usually have with schematics is not the tool that is used, but the thought that doesn’t go into what is being communicated.
The worst offenders are those that draw all the parts with the pins arranged as they are on the physical package, rather than being grouped by function and with inputs and outputs separated on opposite sides. Power supply chip datasheets can be horrendous for this.
In my view, schematics are to communicate functional things, not physical things.
I’m not aware of any good tutorials that teach “schematics for communication” (maybe I should write one 🙂
Excellent points Martin.
By the way, looking forward to seeing more on your blog. Including a “Schematics for Communications”? Would be happy to post a guest blog here if you are interested.
Thanks James, I’ll have to see what I can come up with!