diff --git a/plugins/Kaleidoscope-Hardware-STM32-Test/src/kaleidoscope/device/stm32/Test.cpp b/plugins/Kaleidoscope-Hardware-STM32-Test/src/kaleidoscope/device/stm32/Test.cpp
index 8cf696f5..d9c1b62d 100644
--- a/plugins/Kaleidoscope-Hardware-STM32-Test/src/kaleidoscope/device/stm32/Test.cpp
+++ b/plugins/Kaleidoscope-Hardware-STM32-Test/src/kaleidoscope/device/stm32/Test.cpp
@@ -15,17 +15,17 @@
  * this program. If not, see <http://www.gnu.org/licenses/>.
  */
 
-#ifdef ARDUINO_GD32F303ZE_EVAL
+#ifdef KBIO_TEST
 
 #include "kaleidoscope/Runtime.h"
 #include "kaleidoscope/driver/keyscanner/Base_Impl.h"
 
 namespace kaleidoscope {
 namespace device {
-namespace gd32 {
+namespace stm32 {
 
-} // namespace gd32
+} // namespace stm32
 } // namespace device
 } // namespace kaleidoscope
 
-#endif // ifdef ARDUINO_GD32F303ZE_EVAL
+#endif // ifdef KBIO_TEST
diff --git a/plugins/Kaleidoscope-Hardware-STM32-Test/src/kaleidoscope/device/stm32/Test.h b/plugins/Kaleidoscope-Hardware-STM32-Test/src/kaleidoscope/device/stm32/Test.h
index 5a2129f1..f4e7feea 100644
--- a/plugins/Kaleidoscope-Hardware-STM32-Test/src/kaleidoscope/device/stm32/Test.h
+++ b/plugins/Kaleidoscope-Hardware-STM32-Test/src/kaleidoscope/device/stm32/Test.h
@@ -22,16 +22,25 @@
 #include <Arduino.h>
 
 #include "kaleidoscope/device/Base.h"
+#include "kaleidoscope/driver/hid/RCMComposite.h"
 
 namespace kaleidoscope {
 namespace device {
 namespace stm32 {
 
-struct TestProps: kaleidoscope::device::BaseProps {
+struct TestProps: public kaleidoscope::device::BaseProps {
+  typedef kaleidoscope::driver::hid::RCMCompositeProps HIDProps;
+  typedef kaleidoscope::driver::hid::RCMComposite<HIDProps> HID;
+
   static constexpr const char *short_name = "KBIOTest";
 };
 
-class Test: public kaleidoscope::device::Base<TestProps> {};
+class Test: public kaleidoscope::device::Base<TestProps> {
+ public:
+  auto serialPort() -> decltype(kaleidoscope::driver::hid::rcmcomposite::CompositeSerial) & {
+    return kaleidoscope::driver::hid::rcmcomposite::CompositeSerial;
+  }
+};
 
 #define PER_KEY_DATA(dflt,                                           \
          R0C0, R0C1                                                  \
diff --git a/src/kaleidoscope/driver/hid/RCMComposite.cpp b/src/kaleidoscope/driver/hid/RCMComposite.cpp
new file mode 100644
index 00000000..7990b639
--- /dev/null
+++ b/src/kaleidoscope/driver/hid/RCMComposite.cpp
@@ -0,0 +1,32 @@
+// -*- mode: c++ -*-
+/* Kaleidoscope - Firmware for computer input devices
+ * Copyright (C) 2021  Keyboard.io, Inc.
+ *
+ * This program is free software: you can redistribute it and/or modify it under
+ * the terms of the GNU General Public License as published by the Free Software
+ * Foundation, version 3.
+ *
+ * This program is distributed in the hope that it will be useful, but WITHOUT
+ * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or FITNESS
+ * FOR A PARTICULAR PURPOSE. See the GNU General Public License for more
+ * details.
+ *
+ * You should have received a copy of the GNU General Public License along with
+ * this program. If not, see <http://www.gnu.org/licenses/>.
+ */
+
+#include "kaleidoscope/driver/hid/RCMComposite.h"
+
+namespace kaleidoscope {
+namespace driver {
+namespace hid {
+namespace rcmcomposite {
+
+USBHID RCMHID;
+HIDKeyboard RCMKeyboard(RCMHID);
+USBCompositeSerial CompositeSerial;
+
+} // namespace rcmcomposite
+} // namespace hid
+} // namespace driver
+} // namespace kaleidoscope
diff --git a/src/kaleidoscope/driver/hid/RCMComposite.h b/src/kaleidoscope/driver/hid/RCMComposite.h
new file mode 100644
index 00000000..ab5ded64
--- /dev/null
+++ b/src/kaleidoscope/driver/hid/RCMComposite.h
@@ -0,0 +1,56 @@
+// -*- mode: c++ -*-
+/* Kaleidoscope - Firmware for computer input devices
+ * Copyright (C) 2021  Keyboard.io, Inc.
+ *
+ * This program is free software: you can redistribute it and/or modify it under
+ * the terms of the GNU General Public License as published by the Free Software
+ * Foundation, version 3.
+ *
+ * This program is distributed in the hope that it will be useful, but WITHOUT
+ * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or FITNESS
+ * FOR A PARTICULAR PURPOSE. See the GNU General Public License for more
+ * details.
+ *
+ * You should have received a copy of the GNU General Public License along with
+ * this program. If not, see <http://www.gnu.org/licenses/>.
+ */
+
+#pragma once
+
+#include <Arduino.h>
+#include <USBComposite.h>
+
+#include "kaleidoscope/driver/hid/Base.h"
+
+#include "rcmcomposite/Keyboard.h"
+//#include "rcmcomposite/Mouse.h"
+
+namespace kaleidoscope {
+namespace driver {
+namespace hid {
+
+namespace rcmcomposite {
+extern USBHID RCMHID;
+extern HIDKeyboard RCMKeyboard;
+extern USBCompositeSerial CompositeSerial;
+}
+
+struct RCMCompositeProps: public BaseProps {
+  typedef rcmcomposite::KeyboardProps KeyboardProps;
+  typedef rcmcomposite::Keyboard<KeyboardProps> Keyboard;
+  //  typedef rcmcomposite::MouseProps MouseProps;
+  //  typedef rcmcomposite::Mouse<MouseProps> Mouse;
+};
+
+template <typename _Props>
+class RCMComposite: public Base<_Props> {
+ public:
+  void setup() {
+    //rcmcomposite::RCMHID.begin(rcmcomposite::CompositeSerial, HID_KEYBOARD_MOUSE);
+    rcmcomposite::RCMHID.begin(HID_KEYBOARD_MOUSE);
+  }
+};
+
+} // namespace hid
+} // namespace driver
+} // namespace kaleidoscope
diff --git a/src/kaleidoscope/driver/hid/rcmcomposite/Keyboard.h b/src/kaleidoscope/driver/hid/rcmcomposite/Keyboard.h
new file mode 100644
index 00000000..95dbff8c
--- /dev/null
+++ b/src/kaleidoscope/driver/hid/rcmcomposite/Keyboard.h
@@ -0,0 +1,95 @@
+// -*- mode: c++ -*-
+/* Kaleidoscope - Firmware for computer input devices
+ * Copyright (C) 2021  Keyboard.io, Inc.
+ *
+ * This program is free software: you can redistribute it and/or modify it under
+ * the terms of the GNU General Public License as published by the Free Software
+ * Foundation, version 3.
+ *
+ * This program is distributed in the hope that it will be useful, but WITHOUT
+ * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or FITNESS
+ * FOR A PARTICULAR PURPOSE. See the GNU General Public License for more
+ * details.
+ *
+ * You should have received a copy of the GNU General Public License along with
+ * this program. If not, see <http://www.gnu.org/licenses/>.
+ */
+
+#pragma once
+
+#include <Arduino.h>
+#include <USBComposite.h>
+
+#include "kaleidoscope/driver/hid/base/Keyboard.h"
+
+namespace kaleidoscope {
+namespace driver {
+namespace hid {
+namespace rcmcomposite {
+
+extern USBHID RCMHID;
+extern HIDKeyboard RCMKeyboard;
+
+class BootKeyboardWrapper {
+ public:
+  BootKeyboardWrapper() {}
+
+  void begin() {}
+
+  uint8_t getProtocol() {
+    return 0;
+  }
+  void setProtocol(uint8_t protocol) {}
+  void setDefaultProtocol(uint8_t protocol) {}
+
+  void sendReport() {
+    RCMKeyboard.sendReport();
+  }
+
+  void press(uint8_t code) {
+    RCMKeyboard.press(code);
+  }
+  void release(uint8_t code) {
+    RCMKeyboard.release(code);
+  }
+  void releaseAll() {
+    RCMKeyboard.releaseAll();
+  }
+
+  bool isKeyPressed(uint8_t code) {
+    //return BootKeyboard.isKeyPressed(code);
+    return 0;
+  }
+  bool isModifierActive(uint8_t code) {
+    //return BootKeyboard.isModifierActive(code);
+    return 0;
+  }
+  bool wasModifierActive(uint8_t code) {
+    //return BootKeyboard.wasModifierActive(code);
+    return 0;
+  }
+  bool isAnyModifierActive() {
+    //return BootKeyboard.isAnyModifierActive();
+    return 0;
+  }
+  bool wasAnyModifierActive() {
+    //return BootKeyboard.wasAnyModifierActive();
+    return 0;
+  }
+
+  uint8_t getLeds() {
+    return RCMKeyboard.getLEDs();
+  }
+};
+
+struct KeyboardProps: public base::KeyboardProps {
+  typedef BootKeyboardWrapper BootKeyboard;
+};
+
+template <typename _Props>
+class Keyboard: public base::Keyboard<_Props> {};
+
+} // namespace rcmcomposite
+} // namespace hid
+} // namespace driver
+} // namespace keyboardio