Add example for the weak linking

examples/weak_linking/src/sensor.c

@@ -0,0 +1,32 @@
+
+#include <string.h>
+
+#include "sensor.h"
+#include "bus.h"
+
+#define SENSOR_ADDRESS 0xAA
+#define SENSOR_REG_READ 0xF0 
+float LOCAL_buffer[4];
+
+bool sensor_init()
+{
+    memset( LOCAL_buffer, 0x00, sizeof(LOCAL_buffer));
+    return true;
+}
+
+float sensor_read()
+{
+    char data[4] = { 0xFF, 0xFF, 0x00, 0x00 };
+    bus_read_write( SENSOR_ADDRESS, SENSOR_REG_READ, (uint8_t*)&data, 4, false );
+    
+    if (data[0] != 0x10)
+    {
+        runtime_error("sensor read failed");
+    }
+    
+    float ret_value = data[1] + data[2] / 256.0;
+    return ret_value;
+}
+
+
+