diff --git a/dbus/dbusutil.cpp b/dbus/dbusutil.cpp
new file mode 100644
index 0000000..fc67439
--- /dev/null
+++ b/dbus/dbusutil.cpp
@@ -0,0 +1,58 @@
+#include "util.hpp"
+
+#include <cmath>
+#include <iostream>
+#include <set>
+#include <variant>
+
+using Property = std::string;
+using Value = std::variant<int64_t, double, std::string, bool>;
+using PropertyMap = std::map<Property, Value>;
+
+namespace pid_control
+{
+
+std::string getSensorPath(const std::string& type, const std::string& id)
+{
+    std::string layer = type;
+    if (type == "fan")
+    {
+        layer = "fan_tach";
+    }
+    else if (type == "temp")
+    {
+        layer = "temperature";
+    }
+    else
+    {
+        layer = "unknown"; // TODO(venture): Need to handle.
+    }
+
+    return std::string("/xyz/openbmc_project/sensors/" + layer + "/" + id);
+}
+
+std::string getMatch(const std::string& type, const std::string& id)
+{
+    return std::string("type='signal',"
+                       "interface='org.freedesktop.DBus.Properties',"
+                       "member='PropertiesChanged',"
+                       "path='" +
+                       getSensorPath(type, id) + "'");
+}
+
+bool validType(const std::string& type)
+{
+    static std::set<std::string> valid = {"fan", "temp"};
+    return (valid.find(type) != valid.end());
+}
+
+void scaleSensorReading(const double min, const double max, double& value)
+{
+    if (max <= 0 || max <= min)
+    {
+        return;
+    }
+    value /= (max - min);
+}
+
+} // namespace pid_control