dht11 implementation Issue #183

components/src/main/java/com/opensourcewithslu/components/controllers/DHT11Controller.java

@@ -0,0 +1,25 @@
+package com.opensourcewithslu.components.controllers;
+
+import com.opensourcewithslu.inputdevices.DHT11Helper;
+import com.pi4j.io.gpio.digital.DigitalInput;
+import io.micronaut.http.annotation.Controller;
+import io.micronaut.http.annotation.Get;
+import jakarta.inject.Named;
+
+@Controller("/dht11Sensor")
+public class DHT11Controller {
+
+    private final DHT11Helper dht11Helper;
+
+    public DHT11Controller(@Named("dht11-sensor-input") DigitalInput dht11In) {
+        this.dht11Helper = new DHT11Helper(dht11In);
+    }
+
+    @Get("/getData")
+    public String getData() {
+        float temperature = dht11Helper.temperature;
+        float humidity = dht11Helper.humidity;
+
+        return("Temperature: " + temperature + ", Humidity: " + humidity);
+    }
+}

components/src/main/resources/application.yml

@@ -99,6 +99,12 @@ pi4j:
       pull: PULL_DOWN
       debounce: 30000
       provider: pigpio-digital-input
+    dht11-sensor:
+      name: DHT11 Sensor
+      address: 17
+      pull: PULL_DOWN
+      debounce: 10000
+      provider: pigpio-digital-input
   ### DIGITAL OUTPUTS
   digital-output:
     # tag::digitalOutput[]

pi4micronaut-utils/src/main/java/com/opensourcewithslu/inputdevices/DHT11Helper.java

@@ -0,0 +1,97 @@
+package com.opensourcewithslu.inputdevices;
+
+import com.pi4j.io.gpio.digital.DigitalInput;
+import com.pi4j.io.gpio.digital.DigitalState;
+import org.slf4j.Logger;
+import org.slf4j.LoggerFactory;
+
+public class DHT11Helper {
+
+    private static final Logger log = LoggerFactory.getLogger(DHT11Helper.class);
+
+    private final DigitalInput dht11Input;
+
+    public float temperature;
+
+    public float humidity;
+
+    private final int[] byteStream = new int[5];
+
+    public DHT11Helper(DigitalInput sensorInput)
+    {
+        this.dht11Input = sensorInput;
+
+        initialize();
+    }
+
+    public void initialize()
+    {
+        log.info("Initializing DHT11 Sensor");
+
+        dht11Input.addListener(e -> {
+            if(e.state() == DigitalState.LOW)
+            {
+                return;
+            }
+
+            int j = 0;
+            for (int i = 0; i < byteStream.length; i++)
+            {
+                int counter = 0;
+                while (dht11Input.isLow())
+                {
+                    counter++;
+                    if (counter == 255)
+                        break;
+                }
+
+                byteStream[i] = counter;
+
+                counter = 0;
+                while (dht11Input.isHigh())
+                {
+                    counter++;
+                    if (counter == 255)
+                        break;
+                }
+
+                for (int k = 0; k < 8; k++)
+                {
+                    counter = 0;
+                    while (dht11Input.isLow())
+                    {
+                        counter++;
+                        if (counter == 255)
+                            break;
+                    }
+
+                    byteStream[j] <<= 1;
+                    if (counter > 16)
+                        byteStream[j] |= 1;
+
+                    counter = 0;
+                    while (dht11Input.isHigh())
+                    {
+                        counter++;
+                        if (counter == 255)
+                            break;
+                    }
+
+                    if (counter == 255)
+                        break;
+                }
+                j++;
+            }
+
+            if ((j >= 40) && (byteStream[4] == ((byteStream[0] + byteStream[1] + byteStream[2] + byteStream[3]) & 0xFF)))
+            {
+                log.info("Successfully read data from DHT11 sensor");
+
+                humidity = byteStream[0];
+                temperature = byteStream[2];
+            }
+            else
+                log.info("Failed to read data from DHT11 sensor");
+        });
+    }
+}