diff --git a/src/IpmbSensor.cpp b/src/IpmbSensor.cpp
index 5b4649b..30531bf 100644
--- a/src/IpmbSensor.cpp
+++ b/src/IpmbSensor.cpp
@@ -25,13 +25,10 @@
 
 #include <boost/asio/error.hpp>
 #include <boost/asio/io_context.hpp>
-#include <boost/asio/post.hpp>
 #include <boost/asio/steady_timer.hpp>
 #include <boost/container/flat_map.hpp>
 #include <sdbusplus/asio/connection.hpp>
 #include <sdbusplus/asio/object_server.hpp>
-#include <sdbusplus/bus.hpp>
-#include <sdbusplus/bus/match.hpp>
 #include <sdbusplus/message.hpp>
 #include <sdbusplus/message/native_types.hpp>
 
@@ -40,7 +37,6 @@
 #include <chrono>
 #include <cstddef>
 #include <cstdint>
-#include <functional>
 #include <iostream>
 #include <limits>
 #include <memory>
@@ -53,9 +49,6 @@
 
 constexpr const bool debug = false;
 
-constexpr const char* sensorType = "IpmbSensor";
-constexpr const char* sdrInterface = "IpmbDevice";
-
 static constexpr double ipmbMaxReading = 0xFF;
 static constexpr double ipmbMinReading = 0;
 
@@ -67,11 +60,6 @@
 
 static constexpr const char* sensorPathPrefix = "/xyz/openbmc_project/sensors/";
 
-boost::container::flat_map<std::string, std::shared_ptr<IpmbSensor>> sensors;
-boost::container::flat_map<uint8_t, std::shared_ptr<IpmbSDRDevice>> sdrsensor;
-
-std::unique_ptr<boost::asio::steady_timer> initCmdTimer;
-
 IpmbSensor::IpmbSensor(std::shared_ptr<sdbusplus::asio::connection>& conn,
                        boost::asio::io_context& io,
                        const std::string& sensorName,
@@ -279,7 +267,9 @@
     thresholds::checkThresholds(this);
 }
 
-bool IpmbSensor::processReading(const std::vector<uint8_t>& data, double& resp)
+bool IpmbSensor::processReading(ReadingFormat readingFormat, uint8_t command,
+                                const std::vector<uint8_t>& data, double& resp,
+                                size_t errCount)
 {
     switch (readingFormat)
     {
@@ -299,8 +289,7 @@
             {
                 if (errCount == 0U)
                 {
-                    std::cerr << "Invalid data length returned for " << name
-                              << "\n";
+                    std::cerr << "Invalid data length returned\n";
                 }
                 return false;
             }
@@ -313,8 +302,7 @@
             {
                 if (errCount == 0U)
                 {
-                    std::cerr << "Invalid data length returned for " << name
-                              << "\n";
+                    std::cerr << "Invalid data length returned\n";
                 }
                 return false;
             }
@@ -329,8 +317,7 @@
             {
                 if (errCount == 0U)
                 {
-                    std::cerr << "Invalid data length returned for " << name
-                              << "\n";
+                    std::cerr << "Invalid data length returned\n";
                 }
                 return false;
             }
@@ -344,8 +331,7 @@
             {
                 if (errCount == 0U)
                 {
-                    std::cerr << "Invalid data length returned for " << name
-                              << "\n";
+                    std::cerr << "Invalid data length returned\n";
                 }
                 return false;
             }
@@ -391,7 +377,7 @@
 
     double value = 0;
 
-    if (!processReading(data, value))
+    if (!processReading(readingFormat, command, data, value, errCount))
     {
         incrementError();
         read();
@@ -558,8 +544,7 @@
                 std::vector<thresholds::Threshold> sensorThresholds;
                 if (!parseThresholdsFromConfig(interfaces, sensorThresholds))
                 {
-                    std::cerr << "error populating thresholds for " << name
-                              << "\n";
+                    std::cerr << "error populating thresholds " << name << "\n";
                 }
                 uint8_t deviceAddress = loadVariant<uint8_t>(cfg, "Address");
 
@@ -616,69 +601,6 @@
         "org.freedesktop.DBus.ObjectManager", "GetManagedObjects");
 }
 
-void sdrHandler(sdbusplus::message_t& message,
-                std::shared_ptr<sdbusplus::asio::connection>& dbusConnection)
-{
-    std::string objectName;
-    SensorBaseConfigMap values;
-    message.read(objectName, values);
-
-    auto findBus = values.find("Bus");
-    if (findBus == values.end())
-    {
-        return;
-    }
-
-    uint8_t busIndex = loadVariant<uint8_t>(values, "Bus");
-
-    auto& sdrsen = sdrsensor[busIndex];
-    sdrsen = nullptr;
-    sdrsen = std::make_shared<IpmbSDRDevice>(dbusConnection, busIndex);
-    sdrsen->getSDRRepositoryInfo();
-}
-
-void reinitSensors(sdbusplus::message_t& message)
-{
-    constexpr const size_t reinitWaitSeconds = 2;
-    std::string objectName;
-    boost::container::flat_map<std::string, std::variant<std::string>> values;
-    message.read(objectName, values);
-
-    auto findStatus = values.find(power::property);
-    if (findStatus != values.end())
-    {
-        bool powerStatus =
-            std::get<std::string>(findStatus->second).ends_with(".Running");
-        if (powerStatus)
-        {
-            if (!initCmdTimer)
-            {
-                // this should be impossible
-                return;
-            }
-            // we seem to send this command too fast sometimes, wait before
-            // sending
-            initCmdTimer->expires_after(
-                std::chrono::seconds(reinitWaitSeconds));
-
-            initCmdTimer->async_wait([](const boost::system::error_code ec) {
-                if (ec == boost::asio::error::operation_aborted)
-                {
-                    return; // we're being canceled
-                }
-
-                for (const auto& [name, sensor] : sensors)
-                {
-                    if (sensor)
-                    {
-                        sensor->runInitCmd();
-                    }
-                }
-            });
-        }
-    }
-}
-
 void interfaceRemoved(
     sdbusplus::message_t& message,
     boost::container::flat_map<std::string, std::shared_ptr<IpmbSensor>>&
@@ -712,68 +634,3 @@
         }
     }
 }
-
-int main()
-{
-    boost::asio::io_context io;
-    auto systemBus = std::make_shared<sdbusplus::asio::connection>(io);
-    sdbusplus::asio::object_server objectServer(systemBus, true);
-    objectServer.add_manager("/xyz/openbmc_project/sensors");
-    systemBus->request_name("xyz.openbmc_project.IpmbSensor");
-
-    initCmdTimer = std::make_unique<boost::asio::steady_timer>(io);
-
-    boost::asio::post(
-        io, [&]() { createSensors(io, objectServer, sensors, systemBus); });
-
-    boost::asio::steady_timer configTimer(io);
-
-    std::function<void(sdbusplus::message_t&)> eventHandler =
-        [&](sdbusplus::message_t&) {
-        configTimer.expires_after(std::chrono::seconds(1));
-        // create a timer because normally multiple properties change
-        configTimer.async_wait([&](const boost::system::error_code& ec) {
-            if (ec == boost::asio::error::operation_aborted)
-            {
-                return; // we're being canceled
-            }
-            createSensors(io, objectServer, sensors, systemBus);
-            if (sensors.empty())
-            {
-                std::cout << "Configuration not detected\n";
-            }
-        });
-    };
-
-    std::vector<std::unique_ptr<sdbusplus::bus::match_t>> matches =
-        setupPropertiesChangedMatches(
-            *systemBus, std::to_array<const char*>({sensorType}), eventHandler);
-
-    sdbusplus::bus::match_t powerChangeMatch(
-        static_cast<sdbusplus::bus_t&>(*systemBus),
-        "type='signal',interface='" + std::string(properties::interface) +
-            "',path='" + std::string(power::path) + "',arg0='" +
-            std::string(power::interface) + "'",
-        reinitSensors);
-
-    auto matchSignal = std::make_shared<sdbusplus::bus::match_t>(
-        static_cast<sdbusplus::bus_t&>(*systemBus),
-        "type='signal',member='PropertiesChanged',path_namespace='" +
-            std::string(inventoryPath) + "',arg0namespace='" +
-            configInterfaceName(sdrInterface) + "'",
-        [&systemBus](sdbusplus::message_t& msg) {
-        sdrHandler(msg, systemBus);
-    });
-
-    // Watch for entity-manager to remove configuration interfaces
-    // so the corresponding sensors can be removed.
-    auto ifaceRemovedMatch = std::make_shared<sdbusplus::bus::match_t>(
-        static_cast<sdbusplus::bus_t&>(*systemBus),
-        "type='signal',member='InterfacesRemoved',arg0path='" +
-            std::string(inventoryPath) + "/'",
-        [](sdbusplus::message_t& msg) { interfaceRemoved(msg, sensors); });
-
-    setupManufacturingModeMatch(*systemBus);
-    io.run();
-    return 0;
-}
diff --git a/src/IpmbSensor.hpp b/src/IpmbSensor.hpp
index 58f20d5..d22e36d 100644
--- a/src/IpmbSensor.hpp
+++ b/src/IpmbSensor.hpp
@@ -10,6 +10,9 @@
 #include <string>
 #include <vector>
 
+constexpr const char* sensorType = "IpmbSensor";
+constexpr const char* sdrInterface = "IpmbDevice";
+
 enum class IpmbType
 {
     none,
@@ -97,7 +100,9 @@
     std::string getSubTypeUnits() const;
     void loadDefaults();
     void runInitCmd();
-    bool processReading(const std::vector<uint8_t>& data, double& resp);
+    static bool processReading(ReadingFormat readingFormat, uint8_t command,
+                               const std::vector<uint8_t>& data, double& resp,
+                               size_t errCount);
     void parseConfigValues(const SensorBaseConfigMap& entry);
     bool sensorClassType(const std::string& sensorClass);
     void sensorSubType(const std::string& sensorTypeName);
@@ -126,3 +131,14 @@
     void ipmbRequestCompletionCb(const boost::system::error_code& ec,
                                  const IpmbMethodType& response);
 };
+
+void createSensors(
+    boost::asio::io_context& io, sdbusplus::asio::object_server& objectServer,
+    boost::container::flat_map<std::string, std::shared_ptr<IpmbSensor>>&
+        sensors,
+    std::shared_ptr<sdbusplus::asio::connection>& dbusConnection);
+
+void interfaceRemoved(
+    sdbusplus::message_t& message,
+    boost::container::flat_map<std::string, std::shared_ptr<IpmbSensor>>&
+        sensors);
diff --git a/src/IpmbSensorMain.cpp b/src/IpmbSensorMain.cpp
new file mode 100644
index 0000000..9223264
--- /dev/null
+++ b/src/IpmbSensorMain.cpp
@@ -0,0 +1,160 @@
+#include "IpmbSDRSensor.hpp"
+#include "IpmbSensor.hpp"
+#include "Utils.hpp"
+
+#include <boost/asio/error.hpp>
+#include <boost/asio/io_context.hpp>
+#include <boost/asio/post.hpp>
+#include <boost/asio/steady_timer.hpp>
+#include <boost/container/flat_map.hpp>
+#include <sdbusplus/asio/connection.hpp>
+#include <sdbusplus/asio/object_server.hpp>
+#include <sdbusplus/bus.hpp>
+#include <sdbusplus/bus/match.hpp>
+#include <sdbusplus/message.hpp>
+
+#include <array>
+#include <chrono>
+#include <cstddef>
+#include <cstdint>
+#include <functional>
+#include <iostream>
+#include <memory>
+#include <string>
+#include <variant>
+#include <vector>
+
+std::unique_ptr<boost::asio::steady_timer> initCmdTimer;
+boost::container::flat_map<std::string, std::shared_ptr<IpmbSensor>> sensors;
+boost::container::flat_map<uint8_t, std::shared_ptr<IpmbSDRDevice>> sdrsensor;
+
+void sdrHandler(
+    boost::container::flat_map<uint8_t, std::shared_ptr<IpmbSDRDevice>>
+        sdrsensor,
+    sdbusplus::message_t& message,
+    std::shared_ptr<sdbusplus::asio::connection>& dbusConnection)
+{
+    std::string objectName;
+    SensorBaseConfigMap values;
+    message.read(objectName, values);
+
+    auto findBus = values.find("Bus");
+    if (findBus == values.end())
+    {
+        return;
+    }
+
+    uint8_t busIndex = loadVariant<uint8_t>(values, "Bus");
+
+    auto& sdrsen = sdrsensor[busIndex];
+    sdrsen = nullptr;
+    sdrsen = std::make_shared<IpmbSDRDevice>(dbusConnection, busIndex);
+    sdrsen->getSDRRepositoryInfo();
+}
+
+void reinitSensors(sdbusplus::message_t& message)
+{
+    constexpr const size_t reinitWaitSeconds = 2;
+    std::string objectName;
+    boost::container::flat_map<std::string, std::variant<std::string>> values;
+    message.read(objectName, values);
+
+    auto findStatus = values.find(power::property);
+    if (findStatus != values.end())
+    {
+        bool powerStatus =
+            std::get<std::string>(findStatus->second).ends_with(".Running");
+        if (powerStatus)
+        {
+            if (!initCmdTimer)
+            {
+                // this should be impossible
+                return;
+            }
+            // we seem to send this command too fast sometimes, wait before
+            // sending
+            initCmdTimer->expires_after(
+                std::chrono::seconds(reinitWaitSeconds));
+
+            initCmdTimer->async_wait([](const boost::system::error_code ec) {
+                if (ec == boost::asio::error::operation_aborted)
+                {
+                    return; // we're being canceled
+                }
+
+                for (const auto& [name, sensor] : sensors)
+                {
+                    if (sensor)
+                    {
+                        sensor->runInitCmd();
+                    }
+                }
+            });
+        }
+    }
+}
+
+int main()
+{
+    boost::asio::io_context io;
+    auto systemBus = std::make_shared<sdbusplus::asio::connection>(io);
+    sdbusplus::asio::object_server objectServer(systemBus, true);
+    objectServer.add_manager("/xyz/openbmc_project/sensors");
+    systemBus->request_name("xyz.openbmc_project.IpmbSensor");
+
+    initCmdTimer = std::make_unique<boost::asio::steady_timer>(io);
+
+    boost::asio::post(
+        io, [&]() { createSensors(io, objectServer, sensors, systemBus); });
+
+    boost::asio::steady_timer configTimer(io);
+
+    std::function<void(sdbusplus::message_t&)> eventHandler =
+        [&](sdbusplus::message_t&) {
+        configTimer.expires_after(std::chrono::seconds(1));
+        // create a timer because normally multiple properties change
+        configTimer.async_wait([&](const boost::system::error_code& ec) {
+            if (ec == boost::asio::error::operation_aborted)
+            {
+                return; // we're being canceled
+            }
+            createSensors(io, objectServer, sensors, systemBus);
+            if (sensors.empty())
+            {
+                std::cout << "Configuration not detected\n";
+            }
+        });
+    };
+
+    std::vector<std::unique_ptr<sdbusplus::bus::match_t>> matches =
+        setupPropertiesChangedMatches(
+            *systemBus, std::to_array<const char*>({sensorType}), eventHandler);
+
+    sdbusplus::bus::match_t powerChangeMatch(
+        static_cast<sdbusplus::bus_t&>(*systemBus),
+        "type='signal',interface='" + std::string(properties::interface) +
+            "',path='" + std::string(power::path) + "',arg0='" +
+            std::string(power::interface) + "'",
+        reinitSensors);
+
+    auto matchSignal = std::make_shared<sdbusplus::bus::match_t>(
+        static_cast<sdbusplus::bus_t&>(*systemBus),
+        "type='signal',member='PropertiesChanged',path_namespace='" +
+            std::string(inventoryPath) + "',arg0namespace='" +
+            configInterfaceName(sdrInterface) + "'",
+        [&systemBus](sdbusplus::message_t& msg) {
+        sdrHandler(sdrsensor, msg, systemBus);
+    });
+
+    // Watch for entity-manager to remove configuration interfaces
+    // so the corresponding sensors can be removed.
+    auto ifaceRemovedMatch = std::make_shared<sdbusplus::bus::match_t>(
+        static_cast<sdbusplus::bus_t&>(*systemBus),
+        "type='signal',member='InterfacesRemoved',arg0path='" +
+            std::string(inventoryPath) + "/'",
+        [](sdbusplus::message_t& msg) { interfaceRemoved(msg, sensors); });
+
+    setupManufacturingModeMatch(*systemBus);
+    io.run();
+    return 0;
+}
diff --git a/src/meson.build b/src/meson.build
index 429f7c5..6fb66a1 100644
--- a/src/meson.build
+++ b/src/meson.build
@@ -166,6 +166,7 @@
 if get_option('ipmb').allowed()
     executable(
         'ipmbsensor',
+        'IpmbSensorMain.cpp',
         'IpmbSensor.cpp',
         'IpmbSDRSensor.cpp',
         dependencies: [
diff --git a/tests/meson.build b/tests/meson.build
index e5ad2ea..21f44a0 100644
--- a/tests/meson.build
+++ b/tests/meson.build
@@ -36,3 +36,22 @@
         include_directories: '../src',
     ),
 )
+
+test(
+    'test_ipmb',
+    executable(
+        'test_ipmb',
+        '../src/IpmbSensor.cpp',
+        '../src/Utils.cpp',
+        '../src/IpmbSDRSensor.cpp',
+        'test_IpmbSensor.cpp',
+        dependencies: ut_deps_list,
+        link_with: [
+            utils_a,
+            thresholds_a,
+            devicemgmt_a
+        ],
+        implicit_include_directories: false,
+        include_directories: '../src',
+    ),
+)
diff --git a/tests/test_IpmbSensor.cpp b/tests/test_IpmbSensor.cpp
new file mode 100644
index 0000000..3168993
--- /dev/null
+++ b/tests/test_IpmbSensor.cpp
@@ -0,0 +1,23 @@
+#include "IpmbSensor.hpp"
+
+#include <cstddef>
+#include <cstdint>
+#include <vector>
+
+#include <gtest/gtest.h>
+
+namespace
+{
+
+TEST(IPMBSensor, Byte0)
+{
+    std::vector<uint8_t> data;
+    data.push_back(42);
+
+    double responseValue = 0.0;
+    size_t errCount = 0;
+    EXPECT_TRUE(IpmbSensor::processReading(ReadingFormat::byte0, 0, data,
+                                           responseValue, errCount));
+    EXPECT_EQ(responseValue, 42.0);
+}
+} // namespace