Controversial position: the world needs more buttons. We’ve gotten so far away from physical interfaces like buttons, knobs, and switches in favor of sleek but sterile touch-screen “controls” that when we see something like this big red button so toddlers can start a TV show, we just have to latch onto the story and see what it’s all about.
As it turns out, the big red button itself is probably the least interesting part of [Mads Chr. Olesen] build. The real meat of the project is the reverse engineering effort needed to get Chromecast to start the show. As [Mads] explains, once upon a time a simple
GET request to a URL was all it took to do so, but no more; Google has repeatedly nerfed the Chromecast API over the years, enough that [Mads] had some digging to do.
Luckily, pyChromecast is a thing, but using it for DRTV, a streaming service of the Danish Broadcasting Corporation, required figuring out the AppID of the DRTV app. It looks like [Mads] used Wireshark to sniff traffic to and from the Chromecast, and netlog-viewer to analyze the capture. That and a little Developer Tools action in Chrome led to all the information needed to modify pyChromecast to support DRTV. The rest of the project consisted of building a box for the huge red arcade button and wiring it up to a Wemos D1. A Raspberry Pi actually talks to the Chromecast, and now the toddler is able to call up his favorite show and pause and restart it at will, no parent required.
We appreciate the reverse engineering heroics [Mads] displays here, which provide good general lessons for other purposes. It’s been a while since we’ve seen a Chromecast physical interface build, too, so we appreciate the refresher.