diff --git a/hal/lib/athena/Relay.cpp b/hal/lib/athena/Relay.cpp
new file mode 100644
index 0000000..3c39869
--- /dev/null
+++ b/hal/lib/athena/Relay.cpp
@@ -0,0 +1,134 @@
+/*----------------------------------------------------------------------------*/
+/* 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 "HAL/Relay.h"
+
+#include "DigitalInternal.h"
+#include "HAL/handles/IndexedHandleResource.h"
+#include "PortsInternal.h"
+
+using namespace hal;
+
+namespace {
+struct Relay {
+  uint8_t channel;
+  bool fwd;
+};
+}
+
+static IndexedHandleResource<HAL_RelayHandle, Relay, kNumRelayChannels,
+                             HAL_HandleEnum::Relay>
+    relayHandles;
+
+// Create a mutex to protect changes to the relay values
+static priority_recursive_mutex digitalRelayMutex;
+
+extern "C" {
+HAL_RelayHandle HAL_InitializeRelayPort(HAL_PortHandle portHandle, HAL_Bool fwd,
+                                        int32_t* status) {
+  initializeDigital(status);
+
+  if (*status != 0) return HAL_kInvalidHandle;
+
+  int16_t channel = getPortHandleChannel(portHandle);
+  if (channel == InvalidHandleIndex) {
+    *status = PARAMETER_OUT_OF_RANGE;
+    return HAL_kInvalidHandle;
+  }
+
+  if (!fwd) channel += kNumRelayHeaders;  // add 4 to reverse channels
+
+  auto handle = relayHandles.Allocate(channel, status);
+
+  if (*status != 0)
+    return HAL_kInvalidHandle;  // failed to allocate. Pass error back.
+
+  auto port = relayHandles.Get(handle);
+  if (port == nullptr) {  // would only occur on thread issue.
+    *status = HAL_HANDLE_ERROR;
+    return HAL_kInvalidHandle;
+  }
+
+  if (!fwd) {
+    // Subtract number of headers to put channel in range
+    channel -= kNumRelayHeaders;
+
+    port->fwd = false;  // set to reverse
+  } else {
+    port->fwd = true;  // set to forward
+  }
+
+  port->channel = static_cast<uint8_t>(channel);
+  return handle;
+}
+
+void HAL_FreeRelayPort(HAL_RelayHandle relayPortHandle) {
+  // no status, so no need to check for a proper free.
+  relayHandles.Free(relayPortHandle);
+}
+
+HAL_Bool HAL_CheckRelayChannel(int32_t channel) {
+  // roboRIO only has 4 headers, and the FPGA has
+  // seperate functions for forward and reverse,
+  // instead of seperate channel IDs
+  return channel < kNumRelayHeaders && channel >= 0;
+}
+
+/**
+ * Set the state of a relay.
+ * Set the state of a relay output.
+ */
+void HAL_SetRelay(HAL_RelayHandle relayPortHandle, HAL_Bool on,
+                  int32_t* status) {
+  auto port = relayHandles.Get(relayPortHandle);
+  if (port == nullptr) {
+    *status = HAL_HANDLE_ERROR;
+    return;
+  }
+  std::lock_guard<priority_recursive_mutex> sync(digitalRelayMutex);
+  uint8_t relays = 0;
+  if (port->fwd) {
+    relays = relaySystem->readValue_Forward(status);
+  } else {
+    relays = relaySystem->readValue_Reverse(status);
+  }
+
+  if (*status != 0) return;  // bad status read
+
+  if (on) {
+    relays |= 1 << port->channel;
+  } else {
+    relays &= ~(1 << port->channel);
+  }
+
+  if (port->fwd) {
+    relaySystem->writeValue_Forward(relays, status);
+  } else {
+    relaySystem->writeValue_Reverse(relays, status);
+  }
+}
+
+/**
+ * Get the current state of the relay channel
+ */
+HAL_Bool HAL_GetRelay(HAL_RelayHandle relayPortHandle, int32_t* status) {
+  auto port = relayHandles.Get(relayPortHandle);
+  if (port == nullptr) {
+    *status = HAL_HANDLE_ERROR;
+    return false;
+  }
+
+  uint8_t relays = 0;
+  if (port->fwd) {
+    relays = relaySystem->readValue_Forward(status);
+  } else {
+    relays = relaySystem->readValue_Reverse(status);
+  }
+
+  return (relays & (1 << port->channel)) != 0;
+}
+}