Help:Diagrams

This wiki can store diagrams as diagrams rather than as uploaded pictures. A diagram lives on its own page, keeps a full edit history like any other page, and can be re-opened and changed by the next person — no hunting for the original file, and no re-uploading a flat image every time something moves.

You need to be logged in and in the writer group to create or change a diagram. Anyone can view them.

Screenshots of the editing interfaces are still to be uploaded. Each section below already points at the image it expects, so uploading a file under exactly the name shown will make it appear here automatically — no further editing of this page needed: FlexDiagrams Mermaid editor.png, FlexDiagrams DOT editor.png, FlexDiagrams Drawio editor.png, FlexDiagrams BPMN editor.png, FlexDiagrams Gantt editor.png. Delete this paragraph once they are all up.

Choosing a format

Namespace	Best for	How you edit it
Mermaid:	Flowcharts, sequence diagrams, state machines, ER diagrams, timelines	Text — a few lines of Mermaid syntax
DOT:	Graphs and trees: signal chains, network maps, workflows	Text — Graphviz DOT syntax
Drawio:	Free-form drawings, block diagrams, anything you want to drag around	Full visual editor (draw.io / diagrams.net)
BPMN:	Formal process diagrams, with elements that can link to wiki pages	Visual editor
Gantt:	Project schedules with dependencies	Visual editor

Mermaid and DOT are the two most useful here for typical hardware, RF and reverse-engineering documentation, and they are the easiest to review in a diff because the source is plain text.

Creating a diagram

The easiest way is to write a red link and click it:

1. On any page, add a link in a diagram namespace, for example [[Mermaid:Meter capture chain]].
2. Save, then click the new red link.
3. The diagram editor opens directly. Fill it in and save.

You can also go straight to the editor for a page that does not exist yet by visiting its URL with ?action=editdiagram on the end.

On a diagram page that already exists, use the Edit diagram tab at the top.

Showing a diagram on another page

Diagram pages are not transcluded with the usual double braces. Use the #display_diagram parser function instead, naming the diagram page including its namespace:

{{#display_diagram:Mermaid:Meter capture chain}}

That renders the diagram inline wherever you put it, so an article can show a diagram that is maintained on its own page. Each section below gives the exact line for that format's example.

One limit to know about: a single page can contain at most one BPMN or Gantt diagram — the extension gives both of them the same internal element name, so a second one on the same page is refused with an error message. Mermaid, DOT and Drawio can be embedded as many times as you like.

Mermaid

Flowcharts, sequence diagrams, state machines, class and ER diagrams, pie charts and timelines, all written as text. Served entirely from this wiki.

Example page: Mermaid:Example diagram — open it in the editor

Its source is simply:

flowchart LR
    A[Smart meter] -->|900 MHz| B(SDR capture)
    B --> C{Decodes?}
    C -->|yes| D[rtlamr output]
    C -->|no| E[Adjust gain / freq]
    E --> B

Embed it in a page with:

{{#display_diagram:Mermaid:Example diagram}}

which renders as:

flowchart LR A[Smart meter] -->|900 MHz| B(SDR capture) B --> C{Decodes?} C -->|yes| D[data output] C -->|no| E[Adjust gain / freq] E --> B

See the Mermaid documentation for the full syntax. Note that this wiki bundles Mermaid 10.9, so diagram types added in Mermaid 11 will not render.

File:FlexDiagrams Mermaid editor.png

The Mermaid editor: type the diagram source in the text box and the preview above it redraws as you type.

DOT

Graphviz DOT source, rendered in your browser by the bundled Viz.js. You describe what connects to what and Graphviz works out the layout. Served entirely from this wiki.

Example page: DOT:Example diagram — open it in the editor

Its source:

digraph FlashExtraction {
    rankdir=LR;
    node [shape=box];
    "Target PCB" -> "Desolder chip";
    "Desolder chip" -> "Socket adapter";
    "Socket adapter" -> "Programmer";
    "Programmer" -> "Binary dump";
    "Binary dump" -> "Analysis";
}

Embed it in a page with:

{{#display_diagram:DOT:Example diagram}}

which renders as:

digraph FlashExtraction { rankdir=LR; node [shape=box]; "Target PCB" -> "Desolder chip"; "Desolder chip" -> "Socket adapter"; "Socket adapter" -> "Programmer"; "Programmer" -> "Binary dump"; "Binary dump" -> "Analysis"; }

File:FlexDiagrams DOT editor.png

The DOT editor: Graphviz source in the text box, with the rendered graph above it.

Drawio

The full draw.io drawing tool, for free-form diagrams you build by dragging shapes around. Good when the layout itself carries meaning — panel layouts, wiring sketches, block diagrams.

Example page: Drawio:Example diagram — open it in the editor

Embed it in a page with:

{{#display_diagram:Drawio:Example diagram}}

which renders as:

One thing to know: the Drawio editor is loaded from the external site embed.diagrams.net while you are editing. Your diagram is saved here on the wiki, not on their servers, and viewing a saved Drawio diagram does not contact them at all — but editing one needs that external site reachable from your browser. The other four formats are served entirely from this wiki.

File:FlexDiagrams Drawio editor.png

The Drawio editor: the full draw.io canvas, shape palette and format panel, embedded in the wiki page.

BPMN

Formal business-process diagrams, drawn with bpmn-js. Worth knowing: an element named [[Some page]] becomes a link to that wiki page, so a process diagram can double as navigation.

Example page: BPMN:Example diagram — open it in the editor

Embed it in a page with:

{{#display_diagram:BPMN:Example diagram}}

which renders as:

That embed uses this page's one BPMN-or-Gantt slot; a second diagram of either type on the same page would be refused.

File:FlexDiagrams BPMN editor.png

The BPMN editor: the shape palette down the left, canvas in the middle, zoom controls on the right.

Gantt

Project schedules with tasks, durations and dependencies, drawn with dhtmlxGantt. Useful for planning a long teardown or a multi-stage project on its own page.

Example page: Gantt:Example diagram — open it in the editor

Embed it in a page with:

{{#display_diagram:Gantt:Example diagram}}

This help page cannot show that live: it already embeds a BPMN diagram above, and only one BPMN-or-Gantt diagram is allowed per page (see above). To see it rendered, open Gantt:Example diagram itself.

File:FlexDiagrams Gantt editor.png

The Gantt editor: task grid on the left, timeline on the right, with zoom controls for hours through years.

Tips

• Diagrams are ordinary pages: History, Talk, watchlisting and the normal backups all apply.
• Because Mermaid and DOT are text, their page histories produce readable diffs — prefer them over an uploaded image when the diagram is likely to change.
• Give diagrams descriptive names, the same as files — Mermaid:Landis Gyr Focus teardown steps beats Mermaid:Diagram 3.
• The five example pages above are meant to be edited and experimented with. If you want a scratch diagram of your own, make a new page rather than overwriting an example.

See also

• Help:Uploading files — for photographs, scans and CAD files
• Extension:Flex Diagrams — the extension providing this