Added temperature sensor support

Signed-off-by: nicolatimeus <[email protected]>

org.eclipse.kura.demo.opcua.server/src/org/eclipse/kura/demo/opcua/server/DemoServerComponent.java

@@ -14,6 +14,7 @@
 import org.eclipse.kura.demo.opcua.server.digital.GrovePiDigitalInSensor;
 import org.eclipse.kura.demo.opcua.server.digital.GrovePiDigitalOutSensor;
 import org.eclipse.kura.demo.opcua.server.i2c.GroveDigitalLightSensor;
+import org.eclipse.kura.demo.opcua.server.i2c.GroveTemperatureSensor;
 import org.eclipse.milo.opcua.sdk.server.OpcUaServer;
 import org.eclipse.milo.opcua.sdk.server.api.config.OpcUaServerConfig;
 import org.eclipse.milo.opcua.sdk.server.nodes.UaFolderNode;
@@ -59,6 +60,7 @@ public void activate(Map<String, Object> properties) {
             logger.warn("interrupted", e);
         }
 
+        sensors.add(new GroveTemperatureSensor("temperatureSensor"));
         sensors.add(new GroveDigitalLightSensor("lightSensor"));
         sensors.add(new GrovePiDigitalOutSensor("buzzer", 6, grovePi));
         sensors.add(new GrovePiDigitalOutSensor("led", 4, grovePi));
@@ -143,7 +145,7 @@ public void deactivate() {
             }
         }
         sensors.clear();
-        
+
         try {
             if (grovePi != null) {
                 logger.info("shutting down grovepi...");

org.eclipse.kura.demo.opcua.server/src/org/eclipse/kura/demo/opcua/server/i2c/GroveTemperatureSensor.java

@@ -0,0 +1,78 @@
+package org.eclipse.kura.demo.opcua.server.i2c;
+
+import java.io.BufferedReader;
+import java.io.File;
+import java.io.IOException;
+import java.io.InputStreamReader;
+
+import org.eclipse.kura.core.util.ProcessUtil;
+import org.eclipse.kura.core.util.SafeProcess;
+import org.eclipse.kura.demo.opcua.server.Sensor;
+import org.eclipse.milo.opcua.sdk.core.AccessLevel;
+import org.eclipse.milo.opcua.sdk.server.api.nodes.VariableNode;
+import org.eclipse.milo.opcua.sdk.server.nodes.AttributeContext;
+import org.eclipse.milo.opcua.stack.core.Identifiers;
+import org.eclipse.milo.opcua.stack.core.UaException;
+import org.eclipse.milo.opcua.stack.core.types.builtin.DataValue;
+import org.eclipse.milo.opcua.stack.core.types.builtin.Variant;
+import org.eclipse.milo.opcua.stack.core.types.builtin.unsigned.UByte;
+import org.slf4j.Logger;
+import org.slf4j.LoggerFactory;
+
+import com.google.common.base.Charsets;
+import com.google.common.io.Files;
+
+public class GroveTemperatureSensor extends Sensor {
+
+    private static final Logger logger = LoggerFactory.getLogger(GroveTemperatureSensor.class);
+
+    private static final String PYTHON_CODE = "import smbus\n" + "import time\n" + "bus = smbus.SMBus(1)\n"
+            + "bus.write_i2c_block_data(0x44, 0x2C, [0x06])\n" + "time.sleep(0.5)\n"
+            + "data = bus.read_i2c_block_data(0x44, 0x00, 6)\n" + "temp = data[0] * 256 + data[1]\n"
+            + "cTemp = -45 + (175 * temp / 65535.0)\n" + "fTemp = -49 + (315 * temp / 65535.0)\n"
+            + "humidity = 100 * (data[3] * 256 + data[4]) / 65535.0\n" + "print \"%.2f\" %cTemp\n";
+
+    public GroveTemperatureSensor(String name) {
+        super(name, Identifiers.Double);
+    }
+
+    @Override
+    public void init() throws IOException {
+        Files.write(PYTHON_CODE, new File("/tmp/temperature.py"), Charsets.UTF_8);
+    }
+
+    @Override
+    public UByte getAccessLevel(AttributeContext context, VariableNode node) throws UaException {
+        return UByte.valueOf(AccessLevel.getMask(AccessLevel.READ_ONLY));
+    }
+
+    @Override
+    public UByte getUserAccessLevel(AttributeContext context, VariableNode node) throws UaException {
+        return UByte.valueOf(AccessLevel.getMask(AccessLevel.READ_ONLY));
+    }
+
+    @Override
+    public DataValue getValue(AttributeContext context, VariableNode node) throws UaException {
+        SafeProcess proc = null;
+        try {
+            proc = ProcessUtil.exec("python /tmp/temperature.py");
+            proc.waitFor();
+
+            try (BufferedReader br = new BufferedReader(new InputStreamReader(proc.getInputStream()))) {
+                String line = br.readLine();
+                return new DataValue(new Variant(Double.parseDouble(line)));
+            }
+        } catch (Exception e) {
+            logger.warn("got exception", e);
+            throw new UaException(e);
+        } finally {
+            if (proc != null) {
+                ProcessUtil.destroy(proc);
+            }
+        }
+    }
+
+    @Override
+    public void close() throws Exception {
+    }
+}