It's a two-hour trip to get to Clacton, but I've been caching there before, and I like it there. There's almost no hills, and I'm biking on a hard surface.
So I went out there today. Just outside, I stopped to do the first cache, but I just couldn't find it. So I carried on down to the sea front, parked, and got on my bike.
I did about 30+ caches today, and at one point, I went back to the first cache that I'd failed on (without realising it was that one) and found it immediately. Huh.
Three multis, and I failed on a puzzle that I thought I had solved, but now I don't think so.
On the Robot Arm mark 2 - I can now pretty reliably detect an event from the Pi, and throw an image onto the 3-inch PAL screen. It's not as easy to do that as I'd thought!