We’ve started a garden at our house in a pair of raised beds. I’ve been pondering about possibly creating a set of sensors to monitor the dryness of the soil in the beds as well as in the container that I have a dwarf Meyer lemon tree going in. I was trying to figure out what a good sensor would be. Ideally, I want a simple, low power computer, which is fairly cheap and easy to deploy. I’ve got more than a few Arduino variants around (Uno, Fio, RedBoards, Nanodes, and Wildfires) and they have more than enough horsepower to do what I anticipate (reading temperature, humidity and moisture settings) but there are two things that make them less than completely satisfactory to me:
- They don’t have any kind of wireless link. You could certainly add one of several kinds, but…
- That adds to an already fairly expensive board. Unos are about twenty five dollars. That seems like a lot. There are simpler boards of course, such as the Pro Mini. Sparkfun has those for about ten dollars.. You can also order Arduinos from Chinese manufacturers to drive the cost down, but a board cost of about ten dollars about the minimum you can get.
It seems to me that a complete node has a minimum cost of around $20 when assembled this way. It’ll include a Pro Mini, a small wireless board, and a couple of cheap sensors. Making the node solar powered would probably cost a few bucks more. But while digging around, I discovered that Low Power Labs had a really cool little board: the Moteino. It’s a very cool little board, offers a choice of different RF choices, and includes versions with and without USB. Do I really need another different Arduino clone?
Sigh. Maybe.