GoPro cameras are getting pretty sophisticated, but they can’t yet read minds: you have to tell them when to start recording. Fortunately, they can be remote controlled very easily over a WiFi connection, and this neat tutorial from [euerdesign] shows how you can use an ESP8266 to build a very cheap GoPro remote. The idea is simple: you press a button connected to the ESP8266, which is programmed with the details of the ad hoc WiFi network that the GoPro creates. It then posts a simple URL request to the GoPro, which starts recording. Total cost? A few bucks for the ESP8266, a button and a few bits of wire.
What the remote does is defined by the URL you set it to request: pretty much all of the features of a GoPro can be controlled this way. If you wanted to get fancy, you could expand this to create a multiple button remote that could do other things, such as change frame rate or start streaming to the interwebs in a situation where you don’t want to risk a smartphone or something equally expensive.