Unless you are simply passionate about web technologies and just really want to work with it, stop trying to chase the latest and greatest here. You will find it remarkably hard to compete for the Javascript/web/whatever jobs as the 20 year old wizz-kids will have more experience than you in web-stuff but will probably need much less money.
Instead focus on improving what you already do, and expand into new areas of the embedded sphere. All that fancy web tech will in the end use and require embedded devices. We will get many more embedded devices, rather than fewer of them. Furthermore, try to expand your embedded domain knowledge. Perhaps there are some really exciting new embedded devices (drones, wireless home management devices, etc) you'd enjoy working on as a hobbyist? Expand into other embedded languages as necessary to work on the range of devices you like (i.e. Objective-C if you want to write iOS apps). You will only really learn properly if you have something concrete you want to do anyway.
The point is; unless you hate what you're doing, you should work on ways to make all those 15 years of embedded experience count. Chasing some Javascript web-stuff will not achieve that.