Free software or online block diagram solution

[sairfan1]

I'm looking for some software to give high level picture of a circuit diagram, please refer to attachment for example.
I'm looking for some free solution online is also good.
Thanks

[SmallCog]

We use Microsoft Visio to do these styles of diagram at work

On the odd occasion I've done something similar at home I've used draw.io which is free and online

If you want things to stay attached so that you can drag the objects around on the screen and the "wires" stay connected to the same places on the object then use "Waypoints" in draw.io rather than drawing with lines

[radiolistener]

you can use microsoft visio for diagrams, this is a standard tool for that

[Infraviolet]

If it's a one-off thing there's a website called yED whic lets you produce block diagrams of that sort of thing in your browser.

But if this is something you'll need to do regularly I'd strongly advise finding a locally run program you can use instead, avoid geting dependent on cloud software.

[mwb1100]

I use open source draw.io (https://www.drawio.com/ and https://github.com/jgraph/drawio) which can work entirely on the web in your browser (https://app.diagrams.net/) or you can install it on your machine locally  (https://github.com/jgraph/drawio-desktop).

I use it for things like flowcharts and very high level block diagrams.  I'm not positive it has widgets for things like LCD displays or electrical components, but since it's been active for a while (6 years), it probably does.

One of the things I like about it (aside from it being pretty easy to use) is that you can save the diagram files as plain XML (just disable the "compressed" option in File/Properties...") and they actually work really well with source control systems.  The diffs can actually give you a good idea of what was changed for changes that aren't too extensive.

[Doctorandus_P]

I've heard this recommended a few times:

https://qelectrotech.org/


I would probably do it in KiCad myself. KiCad has a quite good editor for schematic symbols, so custom symbols are quite easy and quick to make, once you are familiar with the editor.

KiCad is not "ideal" for this task, but it's adequate, and limiting the amount of different tools you have to install, learn, maintain, etc also has it's charmes. I've seen for example also a library for pneumatic and hydraulic schematic symbols for KiCad "floating around".

[Nominal Animal]

I often use Inkscape with a support grid for diagramming.  You can create your own preferred square or axonometric grids (for hexes or triangles), and they are saved along the Inkscape original file; they're part of the document properties.

My own workflow is such that I often use tools like Graphviz and others to generate an initial diagram or graph from text format data (lists of nodes and edges/connections); then I look at it a bit, and redraw it in a nicer form.  During the redrawing my mind wanders all about inside the structural design, and I often get ideas on how to improve the structure I'm diagramming.

While that works very well for me, it may not work well for everyone, of course.

[Terry Bites]

You can download yed for free. https://www.yworks.com/products/yed/download
Run it in compatibility mode (win8, wtf!) in win11.

[tooki]

I use open source draw.io (https://www.drawio.com/ and https://github.com/jgraph/drawio) which can work entirely on the web in your browser (https://app.diagrams.net/) or you can install it on your machine locally  (https://github.com/jgraph/drawio-desktop).

I’ve used this for all my block diagrams for a few years now. It’s not perfect, but it’s a great cross-platform solution.

(My absolute favorite app for block diagrams is OmniGraffle, but that’s Mac and iOS only.)

[Doctorandus_P]

Libreoffice also has a drawing module which can be used to make flowcharts with boxes and arrows.
I have never used it myself much though.