Just had a look at a new Linux device (a Kickstarter project)
https://www.indiegogo.com/projects/o...made-for-iot#/ which opens some interesting opportunities in this space. Towards the end of the article it lists a bunch of third part modules which can be used including Current sensing, temp humidity sensors, display etc. I2C, wifi and other bits already on board.
Not available yet from what I can see but an interesting option for the next iteration of dew controllers (and other smart telescope accessories) .