Posted by Julez |
Jan 09, 2015 @ 11:33 AM | 1,364 Views
mic at wemakethings.net
I recently discovered your Chirp moisture sensor, and it might be what I have been looking for for quite some time.
I have been experimenting with automated plant watering, and after testing out several sensor systems, the only ones which were reliable were tensiometer-based gardena sensors. They have a membrane which closes a switch if the suction (= soil dryness) becomes too high. I use this switch to trigger a solid state relay, which operates a solenoid valve. This is connected to an elevated tank and a small tube. The whole system is switched on by a timer for 3 minutes 3 times a day. If in this time, the tensiometer switch is closed, the valve opens, and the water flows for 3 minutes. This gives the plant around 300ml of water.
It works really well, and the only thing that bugs me is that the sensors are not really solid state, and quite bulky to boot.
I would like to try your sensors, but my knowledge of Arduino is fairly limited, and I have no clue about the I2C protocol at all. My idea would be to tap the voltage used to make the chirper chirp, and use this to switch on my valves.
So my question would be: What is the voltage drop across the piezo buzzer? At what time intervall does it work when it signals the need for watering?
Also, as I understand it, when the battery of the device is changed, it resets and the moisture alarm level must be calibrated again.
I have the idea that it would be more comfortable...Continue Reading