I want to try to give a starting point for drawing wiring diagrams. I found that drawing these helps a lot in understanding which cable has to go where and it makes it also easy to share your thoughts in a systematic manner if you want to get help.It helps before your start soldering or in the case of troubleshooting.
I used draw.io which is a free software which is powerful enough but also simple to learn. Before i came to draw.io which can be installed or used in the browser I tried Inkscape but the connector tool there works, but makes it hard to arrange the lines later.
Start with an empty sketch.
Start with components (e.g. Raspberry Pi)
Find pictures of the components you would like to wire up. Drag and drop them into the sketch. Your can adjust the size based on the gridlines (the spacing of the grid can be adjusted)
Prepare connecting points
For every wire you would like to connect to a solder pad or a through hole you can draw a small circle. I used circles without an outline to spare some time adjusting the color of one more element.
To drag the circles to the exact position, you want to have them, hold ALT while dragging them.around. That prevents them from snapping to the grid.
To get every circle in the same size I like to duplicate the first I have drawn with CTRL + D. Copy and Paste works too.
After adjusting the color of the circles the whole component can be grouped.
Group connecting points with component:
Mark all the circles and the picture of the component (drag a box around them or click on everything you want to highlight while pressing SHIFT) and hit rightclick → group or just press CTRL + G. Now all the circles “belong” to the picture of the component and dont get lost when you rearrange everything later on. Sometimes its necessary to bring the picture of the component to the bottom (Icon in the upper Menu or CTRL+SHIFT + B)
Connect the points:
When you hover with the cursor over one of the circles you will see 8 small dots. If you start clicking on one of them and hold the mouse button down you can drag a line to the next dot of another circle you want to connect.
You can adjust color, strength and the behavior of the waypoints of the line in the right box. I use orthogonal. It’s usefull to arrange the components first and arrange the wires after that.
Additional stuff like a XT 60 (or 30) connector can be combined out of simple shapes out of the flow chart toolbox.
You can add textboxes for additional info.
Thats it. Have fun with draw.io !