OK, so I got carried away with this. I needed a timer that could turn a device on for a few minutes a day. This is for an acid injector to pump 30% HCl into my pool to offset its tendency to go alkaline over time. The pump is capable of shoving a lot of acid in, so short intervals are necessary; on the order of 10 minutes or so a day. Maybe even dropping to every other day in the winter. The timers out there just won't do something like this. I also have thoughts of measuring the volume of acid remaining in the storage bucket and maybe, when I have gathered enough information, only adding acid when a PH reading tells the timer to do it. So, I got an Ardweeny, an XBee, a wall wart and some other stuff and away I went.
The XBee listens to my home network and grabs the time from it so the device knows what day and time it is; that way I can tell it to start dumping acid at 0800 and stop at 0810 every day, every other day, once a week or anything else I want to. I still haven't figured out the best way to measure the acid level in the bucket and have just started learning about measuring PH, but it's coming along. And, I have real estate to spare for additions.
I went with an Ardweeny because I was too lazy to just build my own processor arrangement. I took the wall wart apart and just used the power supply because I wanted everything in one box and the entire wall wart wouldn't fit. The XBee is mounted on an Adafruit adapter because I like the way they work and they already have a power regulator on them. I mounted the Ardweeny and XBee on sockets so I can take them out for reprogramming and in case they fail for some reason. The entire thing fits in a waterproof duplex (US) wall outlet box made of plastic so the XBee can get a good signal. Here is a picture of the device mounted on the fence.
Automation is my way of having time to set in my recliner.