I purchased a Panel Mount Barrel Jack and a DC Wall Plug.
I noticed when I put the plug into the barrel jack, it's a fairly "loose" connection. I can barely move the adapter and the plug practically falls out. The sizes I think are correct (2.1mm and 5.5mm); however, it does seem like the Power Adapter barrel jack should be a bit longer.
Is it a cheap Barrel Jack or cheap Adapter, or is it normal?
There could be something wrong with it, or it could just be "cheap".
Sometimes you can bend the little tab inside (on the outside/ground contact) to make it tighter, and/or if the pin is split you can spread it out a little with an Xacto knife (or some other tool).
Hmmm maybe I'll try bending the tab a little. I also purchased another set of power adapters from Amazon. The end seems to be a little bit longer. Worst case I'll try another barrel jack, too. There are some $5-7 ones on Digi-Key that may be better I guess.
There are two common sizes in use: 5.5 x 2.1 and 5.5 x 2.5. There are other pin sizes in use with a 5.5mm OD as well so it’s a very imperfect system.
If you have a 5.5 x 2.5 plug in a 5.5 x 2.1 socket, it will work but of course it will be a sloppy fit. Most of the sockets I’ve seen on official and clone Arduinos are usually 5.5 x 2.1. Plugs can be just about anything with a 5.5 OD and still fit.
