When making a project with the Circuit Playground, perhaps the most important step is securing the board to the project. This applies whether what you are making is a jacket, box or magic wand. It is safe to use bolts, threads, alligator clips and just about anything else to secure your Circuit Playground. There are a lot of 3.3v and GND pins available, so I recommend using these as your anchor points.
So, there's a couple things that you need to be aware of when securing your board to a project and that's obviously the easiest way to secure your Circuit Playground Express is through the nice big holes that also double as contact pads but as you're probably aware some of these are power and ground. So if we secure our Circuit Playground to a conductive surface then we could short out those pins to each other so it's important to keep the Circuit Playground elevated slightly off of a conductive surface if that's what you're securing it to and to not use the power and ground pins to secure it to things so one of the easiest ways to secure the Circuit Playground is just with alligator clips which you're probably already using for the project. So just by grabbing on to the pads wrapping around whatever your projects are turning it into necklace or whatever you might want and using those to hold the board in place and obviously this isn't a very strong way to connect it, but it can hold something together short term or if it's in kind of a light duty application.
Now what you wouldn't would want to be sure not to do, is to connect between like I was saying the say 3.3 volts and the ground on the Circuit Playground even though those might make convenient connection points that would there's constant power coming out of the 3.3 volts and the V out pins and going to ground would short your battery across the Circuit Playground and that could definitely damage your board. So there's lots of other ways to secure your Circuit Playground if you're making into a wearable you can just sew it on to a fabric or a nice some reusable option is to use something like pipe cleaners to wrap the wire through the holes on up the pipe cleaner and bend it to hold it into place and if you're looking for a more long-term solution for screwing it then bolting it down is always a good option.
So here I've got a 3D printed box where I've printed standoffs at the whole locations for the Circuit Playground and I have two mill bolts going through into the standoffs. Now the holes on the search Playground are just over three mils, so a three mil bolt will fit through just fine and you can bolt it or screw it into just about anything like screwing it down to a piece of wood or work just fine just don't crank down on it so much that you damage the board and be aware that you're using up some of your contact pads with your bolts sometimes. So, it's going to be difficult to get an alligator clip on it afterwards but for many projects that's not really an issue or if you're using a wire soldered on you could still solder it on or even just put it under the screw or bolt and have that and hold the wire in place.
So, if you want exact measurements for the hole spacing, I have that up on the tutorial on the workshop page for the Circuit Playground Express in Chapter Seven. Stick around in the next section we're going to talk about how to 3D print a box for the Circuit Playground.