diff --git a/sensors/aidl/default/Android.bp b/sensors/aidl/default/Android.bp
index 487387d..49841a4 100644
--- a/sensors/aidl/default/Android.bp
+++ b/sensors/aidl/default/Android.bp
@@ -28,12 +28,15 @@
     vendor: true,
     shared_libs: [
         "libbase",
+        "libfmq",
+        "libpower",
         "libbinder_ndk",
         "android.hardware.sensors-V1-ndk",
     ],
     export_include_dirs: ["include"],
     srcs: [
         "Sensors.cpp",
+        "Sensor.cpp",
     ],
     visibility: [
         ":__subpackages__",
@@ -50,6 +53,11 @@
     shared_libs: [
         "libbase",
         "libbinder_ndk",
+        "libfmq",
+        "libpower",
+        "libcutils",
+        "liblog",
+        "libutils",
         "android.hardware.sensors-V1-ndk",
     ],
     static_libs: [
diff --git a/sensors/aidl/default/Sensor.cpp b/sensors/aidl/default/Sensor.cpp
new file mode 100644
index 0000000..50d8841
--- /dev/null
+++ b/sensors/aidl/default/Sensor.cpp
@@ -0,0 +1,434 @@
+/*
+ * Copyright (C) 2021 The Android Open Source Project
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *      http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+#include "sensors-impl/Sensor.h"
+
+#include "utils/SystemClock.h"
+
+#include <cmath>
+
+using ::ndk::ScopedAStatus;
+
+namespace aidl {
+namespace android {
+namespace hardware {
+namespace sensors {
+
+static constexpr int32_t kDefaultMaxDelayUs = 10 * 1000 * 1000;
+
+Sensor::Sensor(ISensorsEventCallback* callback)
+    : mIsEnabled(false),
+      mSamplingPeriodNs(0),
+      mLastSampleTimeNs(0),
+      mCallback(callback),
+      mMode(OperationMode::NORMAL) {
+    mRunThread = std::thread(startThread, this);
+}
+
+Sensor::~Sensor() {
+    std::unique_lock<std::mutex> lock(mRunMutex);
+    mStopThread = true;
+    mIsEnabled = false;
+    mWaitCV.notify_all();
+    lock.release();
+    mRunThread.join();
+}
+
+const SensorInfo& Sensor::getSensorInfo() const {
+    return mSensorInfo;
+}
+
+void Sensor::batch(int64_t samplingPeriodNs) {
+    if (samplingPeriodNs < mSensorInfo.minDelayUs * 1000ll) {
+        samplingPeriodNs = mSensorInfo.minDelayUs * 1000ll;
+    } else if (samplingPeriodNs > mSensorInfo.maxDelayUs * 1000ll) {
+        samplingPeriodNs = mSensorInfo.maxDelayUs * 1000ll;
+    }
+
+    if (mSamplingPeriodNs != samplingPeriodNs) {
+        mSamplingPeriodNs = samplingPeriodNs;
+        // Wake up the 'run' thread to check if a new event should be generated now
+        mWaitCV.notify_all();
+    }
+}
+
+void Sensor::activate(bool enable) {
+    if (mIsEnabled != enable) {
+        std::unique_lock<std::mutex> lock(mRunMutex);
+        mIsEnabled = enable;
+        mWaitCV.notify_all();
+    }
+}
+
+ScopedAStatus Sensor::flush() {
+    // Only generate a flush complete event if the sensor is enabled and if the sensor is not a
+    // one-shot sensor.
+    if (!mIsEnabled ||
+        (mSensorInfo.flags & static_cast<uint32_t>(SensorInfo::SENSOR_FLAG_BITS_ONE_SHOT_MODE))) {
+        return ScopedAStatus::fromServiceSpecificError(
+                static_cast<int32_t>(BnSensors::ERROR_BAD_VALUE));
+    }
+
+    // Note: If a sensor supports batching, write all of the currently batched events for the sensor
+    // to the Event FMQ prior to writing the flush complete event.
+    Event ev;
+    ev.sensorHandle = mSensorInfo.sensorHandle;
+    ev.sensorType = SensorType::META_DATA;
+    EventPayload::MetaData meta = {
+            .what = MetaDataEventType::META_DATA_FLUSH_COMPLETE,
+    };
+    ev.payload.set<EventPayload::Tag::meta>(meta);
+    std::vector<Event> evs{ev};
+    mCallback->postEvents(evs, isWakeUpSensor());
+
+    return ScopedAStatus::ok();
+}
+
+void Sensor::startThread(Sensor* sensor) {
+    sensor->run();
+}
+
+void Sensor::run() {
+    std::unique_lock<std::mutex> runLock(mRunMutex);
+    constexpr int64_t kNanosecondsInSeconds = 1000 * 1000 * 1000;
+
+    while (!mStopThread) {
+        if (!mIsEnabled || mMode == OperationMode::DATA_INJECTION) {
+            mWaitCV.wait(runLock, [&] {
+                return ((mIsEnabled && mMode == OperationMode::NORMAL) || mStopThread);
+            });
+        } else {
+            timespec curTime;
+            clock_gettime(CLOCK_BOOTTIME, &curTime);
+            int64_t now = (curTime.tv_sec * kNanosecondsInSeconds) + curTime.tv_nsec;
+            int64_t nextSampleTime = mLastSampleTimeNs + mSamplingPeriodNs;
+
+            if (now >= nextSampleTime) {
+                mLastSampleTimeNs = now;
+                nextSampleTime = mLastSampleTimeNs + mSamplingPeriodNs;
+                mCallback->postEvents(readEvents(), isWakeUpSensor());
+            }
+
+            mWaitCV.wait_for(runLock, std::chrono::nanoseconds(nextSampleTime - now));
+        }
+    }
+}
+
+bool Sensor::isWakeUpSensor() {
+    return mSensorInfo.flags & static_cast<uint32_t>(SensorInfo::SENSOR_FLAG_BITS_WAKE_UP);
+}
+
+std::vector<Event> Sensor::readEvents() {
+    std::vector<Event> events;
+    Event event;
+    event.sensorHandle = mSensorInfo.sensorHandle;
+    event.sensorType = mSensorInfo.type;
+    event.timestamp = ::android::elapsedRealtimeNano();
+    memset(&event.payload, 0, sizeof(event.payload));
+    readEventPayload(event.payload);
+    events.push_back(event);
+    return events;
+}
+
+void Sensor::setOperationMode(OperationMode mode) {
+    if (mMode != mode) {
+        std::unique_lock<std::mutex> lock(mRunMutex);
+        mMode = mode;
+        mWaitCV.notify_all();
+    }
+}
+
+bool Sensor::supportsDataInjection() const {
+    return mSensorInfo.flags & static_cast<uint32_t>(SensorInfo::SENSOR_FLAG_BITS_DATA_INJECTION);
+}
+
+ScopedAStatus Sensor::injectEvent(const Event& event) {
+    if (event.sensorType == SensorType::ADDITIONAL_INFO) {
+        return ScopedAStatus::ok();
+        // When in OperationMode::NORMAL, SensorType::ADDITIONAL_INFO is used to push operation
+        // environment data into the device.
+    }
+
+    if (!supportsDataInjection()) {
+        return ScopedAStatus::fromExceptionCode(EX_UNSUPPORTED_OPERATION);
+    }
+
+    if (mMode == OperationMode::DATA_INJECTION) {
+        mCallback->postEvents(std::vector<Event>{event}, isWakeUpSensor());
+        return ScopedAStatus::ok();
+    }
+
+    return ScopedAStatus::fromServiceSpecificError(
+            static_cast<int32_t>(BnSensors::ERROR_BAD_VALUE));
+}
+
+OnChangeSensor::OnChangeSensor(ISensorsEventCallback* callback)
+    : Sensor(callback), mPreviousEventSet(false) {}
+
+void OnChangeSensor::activate(bool enable) {
+    Sensor::activate(enable);
+    if (!enable) {
+        mPreviousEventSet = false;
+    }
+}
+
+std::vector<Event> OnChangeSensor::readEvents() {
+    std::vector<Event> events = Sensor::readEvents();
+    std::vector<Event> outputEvents;
+
+    for (auto iter = events.begin(); iter != events.end(); ++iter) {
+        Event ev = *iter;
+        if (!mPreviousEventSet ||
+            memcmp(&mPreviousEvent.payload, &ev.payload, sizeof(ev.payload)) != 0) {
+            outputEvents.push_back(ev);
+            mPreviousEvent = ev;
+            mPreviousEventSet = true;
+        }
+    }
+    return outputEvents;
+}
+
+AccelSensor::AccelSensor(int32_t sensorHandle, ISensorsEventCallback* callback) : Sensor(callback) {
+    mSensorInfo.sensorHandle = sensorHandle;
+    mSensorInfo.name = "Accel Sensor";
+    mSensorInfo.vendor = "Vendor String";
+    mSensorInfo.version = 1;
+    mSensorInfo.type = SensorType::ACCELEROMETER;
+    mSensorInfo.typeAsString = "";
+    mSensorInfo.maxRange = 78.4f;  // +/- 8g
+    mSensorInfo.resolution = 1.52e-5;
+    mSensorInfo.power = 0.001f;          // mA
+    mSensorInfo.minDelayUs = 10 * 1000;  // microseconds
+    mSensorInfo.maxDelayUs = kDefaultMaxDelayUs;
+    mSensorInfo.fifoReservedEventCount = 0;
+    mSensorInfo.fifoMaxEventCount = 0;
+    mSensorInfo.requiredPermission = "";
+    mSensorInfo.flags = static_cast<uint32_t>(SensorInfo::SENSOR_FLAG_BITS_DATA_INJECTION);
+};
+
+void AccelSensor::readEventPayload(EventPayload& payload) {
+    EventPayload::Vec3 vec3 = {
+            .x = 0,
+            .y = 0,
+            .z = -9.8,
+            .status = SensorStatus::ACCURACY_HIGH,
+    };
+    payload.set<EventPayload::Tag::vec3>(vec3);
+}
+
+PressureSensor::PressureSensor(int32_t sensorHandle, ISensorsEventCallback* callback)
+    : Sensor(callback) {
+    mSensorInfo.sensorHandle = sensorHandle;
+    mSensorInfo.name = "Pressure Sensor";
+    mSensorInfo.vendor = "Vendor String";
+    mSensorInfo.version = 1;
+    mSensorInfo.type = SensorType::PRESSURE;
+    mSensorInfo.typeAsString = "";
+    mSensorInfo.maxRange = 1100.0f;       // hPa
+    mSensorInfo.resolution = 0.005f;      // hPa
+    mSensorInfo.power = 0.001f;           // mA
+    mSensorInfo.minDelayUs = 100 * 1000;  // microseconds
+    mSensorInfo.maxDelayUs = kDefaultMaxDelayUs;
+    mSensorInfo.fifoReservedEventCount = 0;
+    mSensorInfo.fifoMaxEventCount = 0;
+    mSensorInfo.requiredPermission = "";
+    mSensorInfo.flags = 0;
+};
+
+void PressureSensor::readEventPayload(EventPayload& payload) {
+    payload.set<EventPayload::Tag::scalar>(1013.25f);
+}
+
+MagnetometerSensor::MagnetometerSensor(int32_t sensorHandle, ISensorsEventCallback* callback)
+    : Sensor(callback) {
+    mSensorInfo.sensorHandle = sensorHandle;
+    mSensorInfo.name = "Magnetic Field Sensor";
+    mSensorInfo.vendor = "Vendor String";
+    mSensorInfo.version = 1;
+    mSensorInfo.type = SensorType::MAGNETIC_FIELD;
+    mSensorInfo.typeAsString = "";
+    mSensorInfo.maxRange = 1300.0f;
+    mSensorInfo.resolution = 0.01f;
+    mSensorInfo.power = 0.001f;          // mA
+    mSensorInfo.minDelayUs = 20 * 1000;  // microseconds
+    mSensorInfo.maxDelayUs = kDefaultMaxDelayUs;
+    mSensorInfo.fifoReservedEventCount = 0;
+    mSensorInfo.fifoMaxEventCount = 0;
+    mSensorInfo.requiredPermission = "";
+    mSensorInfo.flags = 0;
+};
+
+void MagnetometerSensor::readEventPayload(EventPayload& payload) {
+    EventPayload::Vec3 vec3 = {
+            .x = 100.0,
+            .y = 0,
+            .z = 50.0,
+            .status = SensorStatus::ACCURACY_HIGH,
+    };
+    payload.set<EventPayload::Tag::vec3>(vec3);
+}
+
+LightSensor::LightSensor(int32_t sensorHandle, ISensorsEventCallback* callback)
+    : OnChangeSensor(callback) {
+    mSensorInfo.sensorHandle = sensorHandle;
+    mSensorInfo.name = "Light Sensor";
+    mSensorInfo.vendor = "Vendor String";
+    mSensorInfo.version = 1;
+    mSensorInfo.type = SensorType::LIGHT;
+    mSensorInfo.typeAsString = "";
+    mSensorInfo.maxRange = 43000.0f;
+    mSensorInfo.resolution = 10.0f;
+    mSensorInfo.power = 0.001f;           // mA
+    mSensorInfo.minDelayUs = 200 * 1000;  // microseconds
+    mSensorInfo.maxDelayUs = kDefaultMaxDelayUs;
+    mSensorInfo.fifoReservedEventCount = 0;
+    mSensorInfo.fifoMaxEventCount = 0;
+    mSensorInfo.requiredPermission = "";
+    mSensorInfo.flags = static_cast<uint32_t>(SensorInfo::SENSOR_FLAG_BITS_ON_CHANGE_MODE);
+};
+
+void LightSensor::readEventPayload(EventPayload& payload) {
+    payload.set<EventPayload::Tag::scalar>(80.0f);
+}
+
+ProximitySensor::ProximitySensor(int32_t sensorHandle, ISensorsEventCallback* callback)
+    : OnChangeSensor(callback) {
+    mSensorInfo.sensorHandle = sensorHandle;
+    mSensorInfo.name = "Proximity Sensor";
+    mSensorInfo.vendor = "Vendor String";
+    mSensorInfo.version = 1;
+    mSensorInfo.type = SensorType::PROXIMITY;
+    mSensorInfo.typeAsString = "";
+    mSensorInfo.maxRange = 5.0f;
+    mSensorInfo.resolution = 1.0f;
+    mSensorInfo.power = 0.012f;           // mA
+    mSensorInfo.minDelayUs = 200 * 1000;  // microseconds
+    mSensorInfo.maxDelayUs = kDefaultMaxDelayUs;
+    mSensorInfo.fifoReservedEventCount = 0;
+    mSensorInfo.fifoMaxEventCount = 0;
+    mSensorInfo.requiredPermission = "";
+    mSensorInfo.flags = static_cast<uint32_t>(SensorInfo::SENSOR_FLAG_BITS_ON_CHANGE_MODE |
+                                              SensorInfo::SENSOR_FLAG_BITS_WAKE_UP);
+};
+
+void ProximitySensor::readEventPayload(EventPayload& payload) {
+    payload.set<EventPayload::Tag::scalar>(2.5f);
+}
+
+GyroSensor::GyroSensor(int32_t sensorHandle, ISensorsEventCallback* callback) : Sensor(callback) {
+    mSensorInfo.sensorHandle = sensorHandle;
+    mSensorInfo.name = "Gyro Sensor";
+    mSensorInfo.vendor = "Vendor String";
+    mSensorInfo.version = 1;
+    mSensorInfo.type = SensorType::GYROSCOPE;
+    mSensorInfo.typeAsString = "";
+    mSensorInfo.maxRange = 1000.0f * M_PI / 180.0f;
+    mSensorInfo.resolution = 1000.0f * M_PI / (180.0f * 32768.0f);
+    mSensorInfo.power = 0.001f;
+    mSensorInfo.minDelayUs = 10 * 1000;  // microseconds
+    mSensorInfo.maxDelayUs = kDefaultMaxDelayUs;
+    mSensorInfo.fifoReservedEventCount = 0;
+    mSensorInfo.fifoMaxEventCount = 0;
+    mSensorInfo.requiredPermission = "";
+    mSensorInfo.flags = 0;
+};
+
+void GyroSensor::readEventPayload(EventPayload& payload) {
+    EventPayload::Vec3 vec3 = {
+            .x = 0,
+            .y = 0,
+            .z = 0,
+            .status = SensorStatus::ACCURACY_HIGH,
+    };
+    payload.set<EventPayload::Tag::vec3>(vec3);
+}
+
+AmbientTempSensor::AmbientTempSensor(int32_t sensorHandle, ISensorsEventCallback* callback)
+    : OnChangeSensor(callback) {
+    mSensorInfo.sensorHandle = sensorHandle;
+    mSensorInfo.name = "Ambient Temp Sensor";
+    mSensorInfo.vendor = "Vendor String";
+    mSensorInfo.version = 1;
+    mSensorInfo.type = SensorType::AMBIENT_TEMPERATURE;
+    mSensorInfo.typeAsString = "";
+    mSensorInfo.maxRange = 80.0f;
+    mSensorInfo.resolution = 0.01f;
+    mSensorInfo.power = 0.001f;
+    mSensorInfo.minDelayUs = 40 * 1000;  // microseconds
+    mSensorInfo.maxDelayUs = kDefaultMaxDelayUs;
+    mSensorInfo.fifoReservedEventCount = 0;
+    mSensorInfo.fifoMaxEventCount = 0;
+    mSensorInfo.requiredPermission = "";
+    mSensorInfo.flags = static_cast<uint32_t>(SensorInfo::SENSOR_FLAG_BITS_ON_CHANGE_MODE);
+};
+
+void AmbientTempSensor::readEventPayload(EventPayload& payload) {
+    payload.set<EventPayload::Tag::scalar>(40.0f);
+}
+
+RelativeHumiditySensor::RelativeHumiditySensor(int32_t sensorHandle,
+                                               ISensorsEventCallback* callback)
+    : OnChangeSensor(callback) {
+    mSensorInfo.sensorHandle = sensorHandle;
+    mSensorInfo.name = "Relative Humidity Sensor";
+    mSensorInfo.vendor = "Vendor String";
+    mSensorInfo.version = 1;
+    mSensorInfo.type = SensorType::RELATIVE_HUMIDITY;
+    mSensorInfo.typeAsString = "";
+    mSensorInfo.maxRange = 100.0f;
+    mSensorInfo.resolution = 0.1f;
+    mSensorInfo.power = 0.001f;
+    mSensorInfo.minDelayUs = 40 * 1000;  // microseconds
+    mSensorInfo.maxDelayUs = kDefaultMaxDelayUs;
+    mSensorInfo.fifoReservedEventCount = 0;
+    mSensorInfo.fifoMaxEventCount = 0;
+    mSensorInfo.requiredPermission = "";
+    mSensorInfo.flags = static_cast<uint32_t>(SensorInfo::SENSOR_FLAG_BITS_ON_CHANGE_MODE);
+}
+
+void RelativeHumiditySensor::readEventPayload(EventPayload& payload) {
+    payload.set<EventPayload::Tag::scalar>(50.0f);
+}
+
+HingeAngleSensor::HingeAngleSensor(int32_t sensorHandle, ISensorsEventCallback* callback)
+    : OnChangeSensor(callback) {
+    mSensorInfo.sensorHandle = sensorHandle;
+    mSensorInfo.name = "Hinge Angle Sensor";
+    mSensorInfo.vendor = "Vendor String";
+    mSensorInfo.version = 1;
+    mSensorInfo.type = SensorType::HINGE_ANGLE;
+    mSensorInfo.typeAsString = "";
+    mSensorInfo.maxRange = 360.0f;
+    mSensorInfo.resolution = 1.0f;
+    mSensorInfo.power = 0.001f;
+    mSensorInfo.minDelayUs = 40 * 1000;  // microseconds
+    mSensorInfo.maxDelayUs = kDefaultMaxDelayUs;
+    mSensorInfo.fifoReservedEventCount = 0;
+    mSensorInfo.fifoMaxEventCount = 0;
+    mSensorInfo.requiredPermission = "";
+    mSensorInfo.flags = static_cast<uint32_t>(SensorInfo::SENSOR_FLAG_BITS_ON_CHANGE_MODE |
+                                              SensorInfo::SENSOR_FLAG_BITS_WAKE_UP |
+                                              SensorInfo::SENSOR_FLAG_BITS_DATA_INJECTION);
+}
+
+void HingeAngleSensor::readEventPayload(EventPayload& payload) {
+    payload.set<EventPayload::Tag::scalar>(180.0f);
+}
+
+}  // namespace sensors
+}  // namespace hardware
+}  // namespace android
+}  // namespace aidl
diff --git a/sensors/aidl/default/Sensors.cpp b/sensors/aidl/default/Sensors.cpp
index 14bbbbf..65dd304 100644
--- a/sensors/aidl/default/Sensors.cpp
+++ b/sensors/aidl/default/Sensors.cpp
@@ -16,66 +16,139 @@
 
 #include "sensors-impl/Sensors.h"
 
+#include <aidl/android/hardware/common/fmq/SynchronizedReadWrite.h>
+
 using ::aidl::android::hardware::common::fmq::MQDescriptor;
 using ::aidl::android::hardware::common::fmq::SynchronizedReadWrite;
 using ::aidl::android::hardware::sensors::Event;
 using ::aidl::android::hardware::sensors::ISensors;
 using ::aidl::android::hardware::sensors::ISensorsCallback;
 using ::aidl::android::hardware::sensors::SensorInfo;
+using ::ndk::ScopedAStatus;
 
 namespace aidl {
 namespace android {
 namespace hardware {
 namespace sensors {
 
-// TODO(b/195593357): Implement AIDL HAL
-::ndk::ScopedAStatus Sensors::activate(int32_t /* in_sensorHandle */, bool /* in_enabled */) {
-    return ndk::ScopedAStatus::ok();
+ScopedAStatus Sensors::activate(int32_t in_sensorHandle, bool in_enabled) {
+    auto sensor = mSensors.find(in_sensorHandle);
+    if (sensor != mSensors.end()) {
+        sensor->second->activate(in_enabled);
+        return ScopedAStatus::ok();
+    }
+
+    return ScopedAStatus::fromExceptionCode(EX_ILLEGAL_ARGUMENT);
 }
 
-::ndk::ScopedAStatus Sensors::batch(int32_t /* in_sensorHandle */,
-                                    int64_t /* in_samplingPeriodNs */,
-                                    int64_t /* in_maxReportLatencyNs */) {
-    return ndk::ScopedAStatus::ok();
+ScopedAStatus Sensors::batch(int32_t in_sensorHandle, int64_t in_samplingPeriodNs,
+                             int64_t /* in_maxReportLatencyNs */) {
+    auto sensor = mSensors.find(in_sensorHandle);
+    if (sensor != mSensors.end()) {
+        sensor->second->batch(in_samplingPeriodNs);
+        return ScopedAStatus::ok();
+    }
+
+    return ScopedAStatus::fromExceptionCode(EX_ILLEGAL_ARGUMENT);
 }
 
-::ndk::ScopedAStatus Sensors::configDirectReport(int32_t /* in_sensorHandle */,
-                                                 int32_t /* in_channelHandle */,
-                                                 ISensors::RateLevel /* in_rate */,
-                                                 int32_t* /* _aidl_return */) {
-    return ndk::ScopedAStatus::ok();
+ScopedAStatus Sensors::configDirectReport(int32_t /* in_sensorHandle */,
+                                          int32_t /* in_channelHandle */,
+                                          ISensors::RateLevel /* in_rate */,
+                                          int32_t* _aidl_return) {
+    *_aidl_return = EX_UNSUPPORTED_OPERATION;
+
+    return ScopedAStatus::fromExceptionCode(EX_UNSUPPORTED_OPERATION);
 }
 
-::ndk::ScopedAStatus Sensors::flush(int32_t /* in_sensorHandle */) {
-    return ndk::ScopedAStatus::ok();
+ScopedAStatus Sensors::flush(int32_t in_sensorHandle) {
+    auto sensor = mSensors.find(in_sensorHandle);
+    if (sensor != mSensors.end()) {
+        return sensor->second->flush();
+    }
+
+    return ScopedAStatus::fromExceptionCode(EX_ILLEGAL_ARGUMENT);
 }
 
-::ndk::ScopedAStatus Sensors::getSensorsList(std::vector<SensorInfo>* /* _aidl_return */) {
-    return ndk::ScopedAStatus::ok();
+ScopedAStatus Sensors::getSensorsList(std::vector<SensorInfo>* _aidl_return) {
+    for (const auto& sensor : mSensors) {
+        _aidl_return->push_back(sensor.second->getSensorInfo());
+    }
+    return ScopedAStatus::ok();
 }
 
-::ndk::ScopedAStatus Sensors::initialize(
-        const MQDescriptor<Event, SynchronizedReadWrite>& /* in_eventQueueDescriptor */,
-        const MQDescriptor<int32_t, SynchronizedReadWrite>& /* in_wakeLockDescriptor */,
-        const std::shared_ptr<ISensorsCallback>& /* in_sensorsCallback */) {
-    return ndk::ScopedAStatus::ok();
+ScopedAStatus Sensors::initialize(
+        const MQDescriptor<Event, SynchronizedReadWrite>& in_eventQueueDescriptor,
+        const MQDescriptor<int32_t, SynchronizedReadWrite>& in_wakeLockDescriptor,
+        const std::shared_ptr<::aidl::android::hardware::sensors::ISensorsCallback>&
+                in_sensorsCallback) {
+    ScopedAStatus result = ScopedAStatus::ok();
+
+    mEventQueue = std::make_unique<AidlMessageQueue<Event, SynchronizedReadWrite>>(
+            in_eventQueueDescriptor, true /* resetPointers */);
+
+    // Ensure that all sensors are disabled.
+    for (auto sensor : mSensors) {
+        sensor.second->activate(false);
+    }
+
+    // Stop the Wake Lock thread if it is currently running
+    if (mReadWakeLockQueueRun.load()) {
+        mReadWakeLockQueueRun = false;
+        mWakeLockThread.join();
+    }
+
+    // Save a reference to the callback
+    mCallback = in_sensorsCallback;
+
+    // Ensure that any existing EventFlag is properly deleted
+    deleteEventFlag();
+
+    // Create the EventFlag that is used to signal to the framework that sensor events have been
+    // written to the Event FMQ
+    if (EventFlag::createEventFlag(mEventQueue->getEventFlagWord(), &mEventQueueFlag) != OK) {
+        result = ScopedAStatus::fromExceptionCode(EX_ILLEGAL_ARGUMENT);
+    }
+
+    // Create the Wake Lock FMQ that is used by the framework to communicate whenever WAKE_UP
+    // events have been successfully read and handled by the framework.
+    mWakeLockQueue = std::make_unique<AidlMessageQueue<int32_t, SynchronizedReadWrite>>(
+            in_wakeLockDescriptor, true /* resetPointers */);
+
+    if (!mCallback || !mEventQueue || !mWakeLockQueue || mEventQueueFlag == nullptr) {
+        result = ScopedAStatus::fromExceptionCode(EX_ILLEGAL_ARGUMENT);
+    }
+
+    // Start the thread to read events from the Wake Lock FMQ
+    mReadWakeLockQueueRun = true;
+    mWakeLockThread = std::thread(startReadWakeLockThread, this);
+    return result;
 }
 
-::ndk::ScopedAStatus Sensors::injectSensorData(const Event& /* in_event */) {
-    return ndk::ScopedAStatus::ok();
+ScopedAStatus Sensors::injectSensorData(const Event& in_event) {
+    auto sensor = mSensors.find(in_event.sensorHandle);
+    if (sensor != mSensors.end()) {
+        return sensor->second->injectEvent(in_event);
+    }
+    return ScopedAStatus::fromServiceSpecificError(static_cast<int32_t>(ERROR_BAD_VALUE));
 }
 
-::ndk::ScopedAStatus Sensors::registerDirectChannel(const ISensors::SharedMemInfo& /* in_mem */,
-                                                    int32_t* /* _aidl_return */) {
-    return ndk::ScopedAStatus::ok();
+ScopedAStatus Sensors::registerDirectChannel(const ISensors::SharedMemInfo& /* in_mem */,
+                                             int32_t* _aidl_return) {
+    *_aidl_return = EX_UNSUPPORTED_OPERATION;
+
+    return ScopedAStatus::fromExceptionCode(EX_UNSUPPORTED_OPERATION);
 }
 
-::ndk::ScopedAStatus Sensors::setOperationMode(OperationMode /* in_mode */) {
-    return ndk::ScopedAStatus::ok();
+ScopedAStatus Sensors::setOperationMode(OperationMode in_mode) {
+    for (auto sensor : mSensors) {
+        sensor.second->setOperationMode(in_mode);
+    }
+    return ScopedAStatus::ok();
 }
 
-::ndk::ScopedAStatus Sensors::unregisterDirectChannel(int32_t /* in_channelHandle */) {
-    return ndk::ScopedAStatus::ok();
+ScopedAStatus Sensors::unregisterDirectChannel(int32_t /* in_channelHandle */) {
+    return ScopedAStatus::fromExceptionCode(EX_UNSUPPORTED_OPERATION);
 }
 
 }  // namespace sensors
diff --git a/sensors/aidl/default/include/sensors-impl/Sensor.h b/sensors/aidl/default/include/sensors-impl/Sensor.h
new file mode 100644
index 0000000..e6cd3e6
--- /dev/null
+++ b/sensors/aidl/default/include/sensors-impl/Sensor.h
@@ -0,0 +1,168 @@
+/*
+ * Copyright (C) 2021 The Android Open Source Project
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *      http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+#include <thread>
+
+#include <aidl/android/hardware/sensors/BnSensors.h>
+
+namespace aidl {
+namespace android {
+namespace hardware {
+namespace sensors {
+
+class ISensorsEventCallback {
+  public:
+    using Event = ::aidl::android::hardware::sensors::Event;
+
+    virtual ~ISensorsEventCallback(){};
+    virtual void postEvents(const std::vector<Event>& events, bool wakeup) = 0;
+};
+
+class Sensor {
+  public:
+    using OperationMode = ::aidl::android::hardware::sensors::ISensors::OperationMode;
+    using Event = ::aidl::android::hardware::sensors::Event;
+    using EventPayload = ::aidl::android::hardware::sensors::Event::EventPayload;
+    using SensorInfo = ::aidl::android::hardware::sensors::SensorInfo;
+    using SensorType = ::aidl::android::hardware::sensors::SensorType;
+    using MetaDataEventType =
+            ::aidl::android::hardware::sensors::Event::EventPayload::MetaData::MetaDataEventType;
+
+    Sensor(ISensorsEventCallback* callback);
+    virtual ~Sensor();
+
+    const SensorInfo& getSensorInfo() const;
+    void batch(int64_t samplingPeriodNs);
+    virtual void activate(bool enable);
+    ndk::ScopedAStatus flush();
+
+    void setOperationMode(OperationMode mode);
+    bool supportsDataInjection() const;
+    ndk::ScopedAStatus injectEvent(const Event& event);
+
+  protected:
+    void run();
+    virtual std::vector<Event> readEvents();
+    virtual void readEventPayload(EventPayload&) = 0;
+    static void startThread(Sensor* sensor);
+
+    bool isWakeUpSensor();
+
+    bool mIsEnabled;
+    int64_t mSamplingPeriodNs;
+    int64_t mLastSampleTimeNs;
+    SensorInfo mSensorInfo;
+
+    std::atomic_bool mStopThread;
+    std::condition_variable mWaitCV;
+    std::mutex mRunMutex;
+    std::thread mRunThread;
+
+    ISensorsEventCallback* mCallback;
+
+    OperationMode mMode;
+};
+
+class OnChangeSensor : public Sensor {
+  public:
+    OnChangeSensor(ISensorsEventCallback* callback);
+
+    virtual void activate(bool enable) override;
+
+  protected:
+    virtual std::vector<Event> readEvents() override;
+
+  protected:
+    Event mPreviousEvent;
+    bool mPreviousEventSet;
+};
+
+class AccelSensor : public Sensor {
+  public:
+    AccelSensor(int32_t sensorHandle, ISensorsEventCallback* callback);
+
+  protected:
+    virtual void readEventPayload(EventPayload& payload) override;
+};
+
+class GyroSensor : public Sensor {
+  public:
+    GyroSensor(int32_t sensorHandle, ISensorsEventCallback* callback);
+
+  protected:
+    virtual void readEventPayload(EventPayload& payload) override;
+};
+
+class AmbientTempSensor : public OnChangeSensor {
+  public:
+    AmbientTempSensor(int32_t sensorHandle, ISensorsEventCallback* callback);
+
+  protected:
+    virtual void readEventPayload(EventPayload& payload) override;
+};
+
+class PressureSensor : public Sensor {
+  public:
+    PressureSensor(int32_t sensorHandle, ISensorsEventCallback* callback);
+
+  protected:
+    virtual void readEventPayload(EventPayload& payload) override;
+};
+
+class MagnetometerSensor : public Sensor {
+  public:
+    MagnetometerSensor(int32_t sensorHandle, ISensorsEventCallback* callback);
+
+  protected:
+    virtual void readEventPayload(EventPayload& payload) override;
+};
+
+class LightSensor : public OnChangeSensor {
+  public:
+    LightSensor(int32_t sensorHandle, ISensorsEventCallback* callback);
+
+  protected:
+    virtual void readEventPayload(EventPayload& payload) override;
+};
+
+class ProximitySensor : public OnChangeSensor {
+  public:
+    ProximitySensor(int32_t sensorHandle, ISensorsEventCallback* callback);
+
+  protected:
+    virtual void readEventPayload(EventPayload& payload) override;
+};
+
+class RelativeHumiditySensor : public OnChangeSensor {
+  public:
+    RelativeHumiditySensor(int32_t sensorHandle, ISensorsEventCallback* callback);
+
+  protected:
+    virtual void readEventPayload(EventPayload& payload) override;
+};
+
+class HingeAngleSensor : public OnChangeSensor {
+  public:
+    HingeAngleSensor(int32_t sensorHandle, ISensorsEventCallback* callback);
+
+  protected:
+    virtual void readEventPayload(EventPayload& payload) override;
+};
+
+}  // namespace sensors
+}  // namespace hardware
+}  // namespace android
+}  // namespace aidl
diff --git a/sensors/aidl/default/include/sensors-impl/Sensors.h b/sensors/aidl/default/include/sensors-impl/Sensors.h
index b6be4a5..e270d96 100644
--- a/sensors/aidl/default/include/sensors-impl/Sensors.h
+++ b/sensors/aidl/default/include/sensors-impl/Sensors.h
@@ -16,14 +16,52 @@
 
 #pragma once
 
+#include <aidl/android/hardware/common/fmq/SynchronizedReadWrite.h>
 #include <aidl/android/hardware/sensors/BnSensors.h>
+#include <fmq/AidlMessageQueue.h>
+#include <hardware_legacy/power.h>
+#include <map>
+#include "Sensor.h"
 
 namespace aidl {
 namespace android {
 namespace hardware {
 namespace sensors {
 
-class Sensors : public BnSensors {
+using aidl::android::hardware::common::fmq::SynchronizedReadWrite;
+using ::android::AidlMessageQueue;
+using ::android::OK;
+using ::android::status_t;
+using ::android::hardware::EventFlag;
+
+class Sensors : public BnSensors, public ISensorsEventCallback {
+    static constexpr const char* kWakeLockName = "SensorsHAL_WAKEUP";
+
+  public:
+    Sensors()
+        : mEventQueueFlag(nullptr),
+          mNextHandle(1),
+          mOutstandingWakeUpEvents(0),
+          mReadWakeLockQueueRun(false),
+          mAutoReleaseWakeLockTime(0),
+          mHasWakeLock(false) {
+        AddSensor<AccelSensor>();
+        AddSensor<GyroSensor>();
+        AddSensor<AmbientTempSensor>();
+        AddSensor<PressureSensor>();
+        AddSensor<MagnetometerSensor>();
+        AddSensor<LightSensor>();
+        AddSensor<ProximitySensor>();
+        AddSensor<RelativeHumiditySensor>();
+        AddSensor<HingeAngleSensor>();
+    }
+
+    virtual ~Sensors() {
+        deleteEventFlag();
+        mReadWakeLockQueueRun = false;
+        mWakeLockThread.join();
+    }
+
     ::ndk::ScopedAStatus activate(int32_t in_sensorHandle, bool in_enabled) override;
     ::ndk::ScopedAStatus batch(int32_t in_sensorHandle, int64_t in_samplingPeriodNs,
                                int64_t in_maxReportLatencyNs) override;
@@ -52,6 +90,124 @@
     ::ndk::ScopedAStatus setOperationMode(
             ::aidl::android::hardware::sensors::ISensors::OperationMode in_mode) override;
     ::ndk::ScopedAStatus unregisterDirectChannel(int32_t in_channelHandle) override;
+
+    void postEvents(const std::vector<Event>& events, bool wakeup) override {
+        std::lock_guard<std::mutex> lock(mWriteLock);
+        if (mEventQueue == nullptr) {
+            return;
+        }
+        if (mEventQueue->write(&events.front(), events.size())) {
+            mEventQueueFlag->wake(
+                    static_cast<uint32_t>(BnSensors::EVENT_QUEUE_FLAG_BITS_READ_AND_PROCESS));
+
+            if (wakeup) {
+                // Keep track of the number of outstanding WAKE_UP events in order to properly hold
+                // a wake lock until the framework has secured a wake lock
+                updateWakeLock(events.size(), 0 /* eventsHandled */);
+            }
+        }
+    }
+
+  protected:
+    // Add a new sensor
+    template <class SensorType>
+    void AddSensor() {
+        std::shared_ptr<SensorType> sensor =
+                std::make_shared<SensorType>(mNextHandle++ /* sensorHandle */, this /* callback */);
+        mSensors[sensor->getSensorInfo().sensorHandle] = sensor;
+    }
+
+    // Utility function to delete the Event Flag
+    void deleteEventFlag() {
+        if (mEventQueueFlag != nullptr) {
+            status_t status = EventFlag::deleteEventFlag(&mEventQueueFlag);
+            if (status != OK) {
+                ALOGI("Failed to delete event flag: %d", status);
+            }
+        }
+    }
+
+    static void startReadWakeLockThread(Sensors* sensors) { sensors->readWakeLockFMQ(); }
+
+    // Function to read the Wake Lock FMQ and release the wake lock when appropriate
+    void readWakeLockFMQ() {
+        while (mReadWakeLockQueueRun.load()) {
+            constexpr int64_t kReadTimeoutNs = 500 * 1000 * 1000;  // 500 ms
+            int32_t eventsHandled = 0;
+
+            // Read events from the Wake Lock FMQ. Timeout after a reasonable amount of time to
+            // ensure that any held wake lock is able to be released if it is held for too long.
+            mWakeLockQueue->readBlocking(
+                    &eventsHandled, 1 /* count */, 0 /* readNotification */,
+                    static_cast<uint32_t>(WAKE_LOCK_QUEUE_FLAG_BITS_DATA_WRITTEN), kReadTimeoutNs);
+            updateWakeLock(0 /* eventsWritten */, eventsHandled);
+        }
+    }
+
+    /**
+     * Responsible for acquiring and releasing a wake lock when there are unhandled WAKE_UP events
+     */
+    void updateWakeLock(int32_t eventsWritten, int32_t eventsHandled) {
+        std::lock_guard<std::mutex> lock(mWakeLockLock);
+        int32_t newVal = mOutstandingWakeUpEvents + eventsWritten - eventsHandled;
+        if (newVal < 0) {
+            mOutstandingWakeUpEvents = 0;
+        } else {
+            mOutstandingWakeUpEvents = newVal;
+        }
+
+        if (eventsWritten > 0) {
+            // Update the time at which the last WAKE_UP event was sent
+            mAutoReleaseWakeLockTime = ::android::uptimeMillis() +
+                                       static_cast<uint32_t>(WAKE_LOCK_TIMEOUT_SECONDS) * 1000;
+        }
+
+        if (!mHasWakeLock && mOutstandingWakeUpEvents > 0 &&
+            acquire_wake_lock(PARTIAL_WAKE_LOCK, kWakeLockName) == 0) {
+            mHasWakeLock = true;
+        } else if (mHasWakeLock) {
+            // Check if the wake lock should be released automatically if
+            // SensorTimeout::WAKE_LOCK_SECONDS has elapsed since the last WAKE_UP event was written
+            // to the Wake Lock FMQ.
+            if (::android::uptimeMillis() > mAutoReleaseWakeLockTime) {
+                ALOGD("No events read from wake lock FMQ for %d seconds, auto releasing wake lock",
+                      WAKE_LOCK_TIMEOUT_SECONDS);
+                mOutstandingWakeUpEvents = 0;
+            }
+
+            if (mOutstandingWakeUpEvents == 0 && release_wake_lock(kWakeLockName) == 0) {
+                mHasWakeLock = false;
+            }
+        }
+    }
+
+  private:
+    // The Event FMQ where sensor events are written
+    std::unique_ptr<AidlMessageQueue<Event, SynchronizedReadWrite>> mEventQueue;
+    // The Wake Lock FMQ that is read to determine when the framework has handled WAKE_UP events
+    std::unique_ptr<AidlMessageQueue<int32_t, SynchronizedReadWrite>> mWakeLockQueue;
+    // Event Flag to signal to the framework when sensor events are available to be read
+    EventFlag* mEventQueueFlag;
+    // Callback for asynchronous events, such as dynamic sensor connections.
+    std::shared_ptr<::aidl::android::hardware::sensors::ISensorsCallback> mCallback;
+    // A map of the available sensors.
+    std::map<int32_t, std::shared_ptr<Sensor>> mSensors;
+    // The next available sensor handle.
+    int32_t mNextHandle;
+    // Lock to protect writes to the FMQs.
+    std::mutex mWriteLock;
+    // Lock to protect acquiring and releasing the wake lock
+    std::mutex mWakeLockLock;
+    // Track the number of WAKE_UP events that have not been handled by the framework
+    uint32_t mOutstandingWakeUpEvents;
+    // A thread to read the Wake Lock FMQ
+    std::thread mWakeLockThread;
+    // Flag to indicate that the Wake Lock Thread should continue to run
+    std::atomic_bool mReadWakeLockQueueRun;
+    // Track the time when the wake lock should automatically be released
+    int64_t mAutoReleaseWakeLockTime;
+    // Flag to indicate if a wake lock has been acquired
+    bool mHasWakeLock;
 };
 
 }  // namespace sensors