diff --git a/wpilibc/sim/src/simulation/SimContinuousOutput.cpp b/wpilibc/sim/src/simulation/SimContinuousOutput.cpp
new file mode 100644
index 0000000..9a907cf
--- /dev/null
+++ b/wpilibc/sim/src/simulation/SimContinuousOutput.cpp
@@ -0,0 +1,25 @@
+/*----------------------------------------------------------------------------*/
+/* Copyright (c) FIRST 2014-2017. All Rights Reserved.                        */
+/* Open Source Software - may be modified and shared by FRC teams. The code   */
+/* must be accompanied by the FIRST BSD license file in the root directory of */
+/* the project.                                                               */
+/*----------------------------------------------------------------------------*/
+
+#include "simulation/SimContinuousOutput.h"
+
+#include "simulation/MainNode.h"
+
+using namespace frc;
+
+SimContinuousOutput::SimContinuousOutput(std::string topic) {
+  pub = MainNode::Advertise<gazebo::msgs::Float64>("~/simulator/" + topic);
+  std::cout << "Initialized ~/simulator/" + topic << std::endl;
+}
+
+void SimContinuousOutput::Set(double speed) {
+  gazebo::msgs::Float64 msg;
+  msg.set_data(speed);
+  pub->Publish(msg);
+}
+
+double SimContinuousOutput::Get() { return speed; }
diff --git a/wpilibc/sim/src/simulation/SimDigitalInput.cpp b/wpilibc/sim/src/simulation/SimDigitalInput.cpp
new file mode 100644
index 0000000..c4dbde6
--- /dev/null
+++ b/wpilibc/sim/src/simulation/SimDigitalInput.cpp
@@ -0,0 +1,24 @@
+/*----------------------------------------------------------------------------*/
+/* Copyright (c) FIRST 2014-2017. All Rights Reserved.                        */
+/* Open Source Software - may be modified and shared by FRC teams. The code   */
+/* must be accompanied by the FIRST BSD license file in the root directory of */
+/* the project.                                                               */
+/*----------------------------------------------------------------------------*/
+
+#include "simulation/SimDigitalInput.h"
+
+#include "simulation/MainNode.h"
+
+using namespace frc;
+
+SimDigitalInput::SimDigitalInput(std::string topic) {
+  sub = MainNode::Subscribe("~/simulator/" + topic, &SimDigitalInput::callback,
+                            this);
+  std::cout << "Initialized ~/simulator/" + topic << std::endl;
+}
+
+bool SimDigitalInput::Get() { return value; }
+
+void SimDigitalInput::callback(const gazebo::msgs::ConstBoolPtr& msg) {
+  value = msg->data();
+}
diff --git a/wpilibc/sim/src/simulation/SimEncoder.cpp b/wpilibc/sim/src/simulation/SimEncoder.cpp
new file mode 100644
index 0000000..141a371
--- /dev/null
+++ b/wpilibc/sim/src/simulation/SimEncoder.cpp
@@ -0,0 +1,55 @@
+/*----------------------------------------------------------------------------*/
+/* Copyright (c) FIRST 2016-2017. All Rights Reserved.                        */
+/* Open Source Software - may be modified and shared by FRC teams. The code   */
+/* must be accompanied by the FIRST BSD license file in the root directory of */
+/* the project.                                                               */
+/*----------------------------------------------------------------------------*/
+
+#include "simulation/SimEncoder.h"
+
+#include "simulation/MainNode.h"
+
+using namespace frc;
+
+SimEncoder::SimEncoder(std::string topic) {
+  commandPub = MainNode::Advertise<gazebo::msgs::GzString>("~/simulator/" +
+                                                           topic + "/control");
+
+  posSub = MainNode::Subscribe("~/simulator/" + topic + "/position",
+                               &SimEncoder::positionCallback, this);
+  velSub = MainNode::Subscribe("~/simulator/" + topic + "/velocity",
+                               &SimEncoder::velocityCallback, this);
+
+  if (commandPub->WaitForConnection(
+          gazebo::common::Time(5.0))) {  // Wait up to five seconds.
+    std::cout << "Initialized ~/simulator/" + topic << std::endl;
+  } else {
+    std::cerr << "Failed to initialize ~/simulator/" + topic +
+                     ": does the encoder exist?"
+              << std::endl;
+  }
+}
+
+void SimEncoder::Reset() { sendCommand("reset"); }
+
+void SimEncoder::Start() { sendCommand("start"); }
+
+void SimEncoder::Stop() { sendCommand("stop"); }
+
+double SimEncoder::GetPosition() { return position; }
+
+double SimEncoder::GetVelocity() { return velocity; }
+
+void SimEncoder::sendCommand(std::string cmd) {
+  gazebo::msgs::GzString msg;
+  msg.set_data(cmd);
+  commandPub->Publish(msg);
+}
+
+void SimEncoder::positionCallback(const gazebo::msgs::ConstFloat64Ptr& msg) {
+  position = msg->data();
+}
+
+void SimEncoder::velocityCallback(const gazebo::msgs::ConstFloat64Ptr& msg) {
+  velocity = msg->data();
+}
diff --git a/wpilibc/sim/src/simulation/SimFloatInput.cpp b/wpilibc/sim/src/simulation/SimFloatInput.cpp
new file mode 100644
index 0000000..8bf8ae3
--- /dev/null
+++ b/wpilibc/sim/src/simulation/SimFloatInput.cpp
@@ -0,0 +1,24 @@
+/*----------------------------------------------------------------------------*/
+/* Copyright (c) FIRST 2014-2017. All Rights Reserved.                        */
+/* Open Source Software - may be modified and shared by FRC teams. The code   */
+/* must be accompanied by the FIRST BSD license file in the root directory of */
+/* the project.                                                               */
+/*----------------------------------------------------------------------------*/
+
+#include "simulation/SimFloatInput.h"
+
+#include "simulation/MainNode.h"
+
+using namespace frc;
+
+SimFloatInput::SimFloatInput(std::string topic) {
+  sub = MainNode::Subscribe("~/simulator/" + topic, &SimFloatInput::callback,
+                            this);
+  std::cout << "Initialized ~/simulator/" + topic << std::endl;
+}
+
+double SimFloatInput::Get() { return value; }
+
+void SimFloatInput::callback(const gazebo::msgs::ConstFloat64Ptr& msg) {
+  value = msg->data();
+}
diff --git a/wpilibc/sim/src/simulation/SimGyro.cpp b/wpilibc/sim/src/simulation/SimGyro.cpp
new file mode 100644
index 0000000..33663bd
--- /dev/null
+++ b/wpilibc/sim/src/simulation/SimGyro.cpp
@@ -0,0 +1,51 @@
+/*----------------------------------------------------------------------------*/
+/* Copyright (c) FIRST 2016-2017. All Rights Reserved.                        */
+/* Open Source Software - may be modified and shared by FRC teams. The code   */
+/* must be accompanied by the FIRST BSD license file in the root directory of */
+/* the project.                                                               */
+/*----------------------------------------------------------------------------*/
+
+#include "simulation/SimGyro.h"
+
+#include "simulation/MainNode.h"
+
+using namespace frc;
+
+SimGyro::SimGyro(std::string topic) {
+  commandPub = MainNode::Advertise<gazebo::msgs::GzString>("~/simulator/" +
+                                                           topic + "/control");
+
+  posSub = MainNode::Subscribe("~/simulator/" + topic + "/position",
+                               &SimGyro::positionCallback, this);
+  velSub = MainNode::Subscribe("~/simulator/" + topic + "/velocity",
+                               &SimGyro::velocityCallback, this);
+
+  if (commandPub->WaitForConnection(
+          gazebo::common::Time(5.0))) {  // Wait up to five seconds.
+    std::cout << "Initialized ~/simulator/" + topic << std::endl;
+  } else {
+    std::cerr << "Failed to initialize ~/simulator/" + topic +
+                     ": does the gyro exist?"
+              << std::endl;
+  }
+}
+
+void SimGyro::Reset() { sendCommand("reset"); }
+
+double SimGyro::GetAngle() { return position; }
+
+double SimGyro::GetVelocity() { return velocity; }
+
+void SimGyro::sendCommand(std::string cmd) {
+  gazebo::msgs::GzString msg;
+  msg.set_data(cmd);
+  commandPub->Publish(msg);
+}
+
+void SimGyro::positionCallback(const gazebo::msgs::ConstFloat64Ptr& msg) {
+  position = msg->data();
+}
+
+void SimGyro::velocityCallback(const gazebo::msgs::ConstFloat64Ptr& msg) {
+  velocity = msg->data();
+}