I recently got a device that has a 2.1mm power connector but in centre-negative configuration.
Unfortunately I don’t have any centre-negative power packs on hand. I could of course just rewire one,
but decided it might be the time to make up a generic any-to-any connector.
In addition to centre-positive and centre-negative output plugs, I included
a 9V battery bypass and polarity rectifier, so that the input supports both centre-positive and centre-negative connections.
And of course an LED power indicator.
As always, all notes, schematics and code are in the Little Electronics & Arduino Projects repo on GitHub
