Refactor project structure: update Java version, remove MQ7 files, and add BMP280 support

hardware/lib/BMP280.c

@@ -0,0 +1,17 @@
+#include "BMP280.h"
+
+
+void BMP280_Init()
+{
+
+}
+
+uint8_t BMP280_DataReady()
+{
+
+}
+
+void BMP280_Read(float &temperature, float &humidity, float &pressure, float &altitude)
+{
+
+}

hardware/lib/MQ7.c

@@ -0,0 +1,30 @@
+#include "MQ7.h"
+ 
+void MQ7_Init()
+{
+    pinMode(digitalMQ7, INPUT);
+    pinMode(analogMQ7, INPUT);
+}
+ 
+void MQ7_Read(float &sensorVolt, float &RSAir, float &R0, float &sensorValue)
+{
+    analogWrite(analogMQ7, 1023);
+    delay(60000);
+    analogWrite(analogMQ7, (1023/5)*1.4 );
+
+    for(int i = 0; i<100; i++)
+    { 
+        sensorValue = sensorValue + analogRead(analogMQ7);
+        delay(90000);
+    }
+
+    sensorValue = sensorValue/100.0;
+    sensorVolt = sensorValue/1024*5.0;
+    RSAir = (5.0-sensorVolt)/sensorVolt;
+    R0 = RSAir/(26+(1/3));
+
+    Serial.print("R0 = ");
+    Serial.println(R0);
+
+    delay(1000);
+}