Software apps and online services
Mimosas are sensitive plants. If you left one without water for a week (whether because of holiday or you simply forget), you will be sorry!
There are many Arduino projects dedicated to this objective, but it depends on what you want:
- Receive a warning (alarm sound, SMS, etc.) and you must go water the plant?
- The device is watering the plant for several months, so you just visit it from time to time.
We selected the second option.
Full detail at: https://sites.google.com/site/pre2arduino/
This is the central unit:
The moisture sensor is in fact from here: BangGood. It is a resistive sensor, which is not corroded as others write in Hackster projects, if you power it on only for several milliseconds per hour, just enough to read the humidity. This one worked like this for months without any sign of corrosion. Just use the attached software. Other issues could occur, such as mud attaching to the sensor and indicating a different local humidity from the rest of the pot. Put it close to the hose to stop watering before it is too much.
Concerning the micro-controller we suggest here the AtTiny85 instead another one with more IO pins, because this one is just good for the purpose (and cheaper).
The whole device is continuously powered by a power adapter of 9V/ 0.5A. In case of power failure, (lasting less than a few days!), it is not a problem. The system will resume from reading the humidity and will start counting hours and days.
Powering the pump is done by a Mosfet board, but ca be done by other means too, e.g. relay. The display can be any other. This one has a parallel interface, so a I2C adapter was needed (AtTiny85 has only 6 pins!!) was just for reuse purpose.