Supporting some of my caches...
I think it was in 2014 or 2015, when I saw your video on YouTube. And when I visted you in 2016, I had a look by myself to it. The main idea is to use a FM transmitter which is sending a message to the radio of your car. I’ve built the first station of my „Scratchy Cache“, which is already archived since long like this.
But after that I wanted to have something much more universal. So I came up wuith the idea, the cacher has to send a SMS with a certain code and will receive a hint. Here’s like it looks on an iPhone:
The SMS, the cacher has to send (green above), must start with a „#“, if not, it’s sorted out. Next is the GC code of the cache, followed by a „#“ again. „S01“ means station 1 of a multi cache. After some few seconds the cacher will receive the reply (grey). It’s in German and saying what to do to start a Simon Says cache.
Finally I used a RTC (real time clock) and it was a real challenge to switch from normal to daylight saving time. Here’s a picture of the setup:
… And here’s a short video, how it works...
You can pick the full sketch here…