I recently build something similar for my balcony. But instead of a $30 raspberry I used a $9 NodeMCU: https://www.splitbrain.org/blog/2017-06/10-automated_plan

I recently build something similar for my balcony. But instead of a $30 raspberry I used a $9 NodeMCU: https://www.splitbrain.org/blog/2017-06/10-automated_plant_watering https://www.splitbrain.org/blog/2017-06/10-automated_plant_w... Also just took me a few evenings instead of months.