Here is an open source plant watering alarm based around the ATtiny44A. It uses a humidity sensor to detect when a plant needs to be watered.
Your favorite plants need plenty of water to grow. If you keep forgetting to water your house plants you might be interested in this plant watering alarm device called Chirp. Chirp uses capacitive humidity sensing technique to measure the moisture level in the soil and alerts the user through short chirps when it is time to water the plant.
Isn’t this the same as:
http://dangerousprototypes.com/2013/08/01/chirp-a-plant-watering-alarm/
Batteries make for toxic landfill.
I
‘d be interested in a DIY low-voltage AC system for projects like this around the house. If you had a 12V rms, 30+ KHz supply how many wall-wart transformers could you eliminate?
Watering alarms, Arduinos, Raspberry Pis, routers, phone answering machine, electric toothbrush charger… the list gets big quite fast. Running them all off a single, high frequency switchmode would surely be more efficient.
I don’t think it is a good idea to run 30+ Khz AC on long cables around the house. I would imagine it would cause interference.
Actually, some alternative lifestyle people here in Australia have done just that. Twisted pair, IIRC.Their biggest problem wasn’t interference – in long runs they started getting reflections from mismatched loads. VSWR sucks.
Yes, it’s definately the same, it’s just an older photo of the prototype.
could go with solar cell + cap. i imagine even in pretty heavy shade you could build up enough charge to come out of sleep every so often to make a quick check.
I have considered this from the first prototype. This would make a cool project to tinker around, but would increase the price substantially – energy harvesting solutions tend to be quite pricey. The project is open source – what if _you_ try to do that?