If you want a device but don't want to have to buy batteries or make a case, there are several sellers on etsy who have pre-finished units. While the T-beams a

If you want a device but don't want to have to buy batteries or make a case, there are several sellers on etsy who have pre-finished units. While the T-beams are nice for having screens and gps, the RAK based devices have better battery life.