Merge pull request #5 from Gnyblast/master

Adding water flow sensor to the library

README.md

@@ -67,6 +67,7 @@ func main() {
 |SW-420|![](img/sw-420.jpg)|Shaking sensor|[example](/example/sw420/main.go)|[auto-air-out](https://github.com/shanghuiyang/rpi-projects/tree/main/projects/autoairout)|
 |US-100|![](img/us-100.jpg)|Ultrasonic distance meter|[example](/example/us100/main.go)|[car](https://github.com/shanghuiyang/rpi-projects/tree/main/projects/car)|
 |Voice Detector|![](img/voice.jpg)|Voice detector|N/A|N/A|
+|Water Flow Sensor|![](img/water_flow_sensor.jpg)|Water flow sensor|[example](/example/water_flow_sensor/main.go)|N/A|
 |ZE08-CH2O|![](img/ze08-ch2o.jpg)|CH2O sensor|[example](/example/ze08ch2o/main.go)|[ch2o-monitor](https://github.com/shanghuiyang/rpi-projects/tree/main/projects/ch2omonitor)|
 |ZP16|![](img/zp16.jpg)|Gas detector|[example](/example/zp16/main.go)|[home-asst](https://github.com/shanghuiyang/rpi-projects/tree/main/projects/homeasst)|
 

dev/water_flow_meter.go

@@ -0,0 +1,21 @@
+package dev
+
+import "github.com/stianeikeland/go-rpio/v4"
+
+// WaterFlowMeter implements Detector interface
+type WaterFlowMeter struct {
+	pin rpio.Pin
+}
+
+// NewWaterFlowMeter ...
+func NewWaterFlowMeter(pin uint8) *WaterFlowMeter {
+	w := &WaterFlowMeter{
+		pin: rpio.Pin(pin),
+	}
+	w.pin.Input()
+	return w
+}
+
+func (w *WaterFlowMeter) Detected() bool {
+	return w.pin.Read() == rpio.High
+}

example/water_flow_sensor/main.go

@@ -0,0 +1,25 @@
+package main
+
+import (
+	"fmt"
+	"time"
+
+	"github.com/shanghuiyang/rpi-devices/dev"
+)
+
+const pulsesPerLiter float32 = 450
+
+func main() {
+	w := dev.NewWaterFlowMeter(17)
+	var numberOfPulsesCounted int = 0
+
+	for {
+		if w.Detected() {
+			numberOfPulsesCounted++
+			fmt.Printf("MiliLiters Flowed: %f", (float32(1000*numberOfPulsesCounted) / pulsesPerLiter))
+			continue
+		}
+
+		time.Sleep(100 * time.Millisecond)
+	}
+}