New Project: Building a water flow based, rain water drip irrigation system

Community General Discussions
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Hi, first post. Here it goes:

I have a large rain barrel connected to a drip irrigation system. As the water level drops, so does the water pressure, so the flow drops. So simple irrigation timers would not work, if I want consistent watering volumes.

Proposed solution: have a water flow meter keep track of the volume of water flowing to the drips, and when the volume gets to a predetermined point, a solenoid is triggered to turn the water off. After a predetermined time, the solenoid is turned back open and the system starts again.

I’m looking at the Adafruit Water Flow Sensor, robotshop.com/productinfo.aspx?pc=RB-Ada-68&lang=en-US as an inexpensive water flow meter (I figure I could calibrate it). Generic sprinkler system solenoids are easy to come by. A small solar panel or batteries could power the system.

Query: What could I use to count the ticks from the water flow sensor (Hall effect pulse output), close and open the solenoid, and program for watering cycles? A friend mentioned that there exists small, handheld computers that can be programed by USB connection to a home computer.

Thanks so much.
Steve

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Hi Steve,

Interesting project! There are a few ways to build such a system.

If you’re looking for a PC-based solution, we have the Phidgets PhidgetEncoder HighSpeed USB Encoder (RB-Phi-48) which you can plug via USB into your computer and use the Phidgets API to count the ticks (water flow volume): the Phidgets API is available in many programming languages.

If you’re looking for a compact non-PC solution, we have many Arduino boards (such as the standard Uno, RB-Ard-34, or the small Pro Mini, RB-Spa-712) that can be used: attach the sensor to digital pins 2 or 3 and use the attachInterrupt() function from the Arduino API, which is available in C.

Depending on how the solenoids is designed, you might need additional components (such as a relay, or maybe just a transistor) to ensure that you don’t over-current the Arduino or PC.

Hope this helps,