But no more! In an effort to solve this problem, and have a bit of fun at the same time, I created the Plant Whisperer. This little device measures the soil moisture every two hours, and reports its status to anyone who might be within earshot - that's right, it talks! The message content depends on the soil condition. For example, if the soil is too dry, the plant might say, "I'M THIRSTY! WATER ME!" If the moisture is okay, it might say "I'M A HAPPY PLANT!" - or maybe something funny like "I SUGGEST YOU BECOME A CARNIVORE." It is also capable of detecting the ambient light level and commenting on that, as well.
Did I mention the cool retro robot voice? Yeah, who wouldn't want that on their houseplant?
The Plant Whisperer is based around a Parallax Propeller, which makes real-time text-to-speech easy to implement. Other major components include a two-channel ADC, a two-hour timer IC, a load switch and an audio amplifier. In total it costs about $30 to build.