diff --git a/config/boards/arm/hw75_dynamic/README.md b/config/boards/arm/hw75_dynamic/README.md
index b70637d2..c93616ce 100644
--- a/config/boards/arm/hw75_dynamic/README.md
+++ b/config/boards/arm/hw75_dynamic/README.md
@@ -16,7 +16,7 @@ HW-75 Dynamic
 - [x] 旋钮力反馈 (FOC)
 - [x] 墨水屏
 - [x] 上位机
-- [ ] 键盘联动
+- [x] 键盘联动
 
 ## 烧录
 
diff --git a/config/boards/arm/hw75_dynamic/app/uart_comm/CMakeLists.txt b/config/boards/arm/hw75_dynamic/app/uart_comm/CMakeLists.txt
index d355405f..087831cd 100644
--- a/config/boards/arm/hw75_dynamic/app/uart_comm/CMakeLists.txt
+++ b/config/boards/arm/hw75_dynamic/app/uart_comm/CMakeLists.txt
@@ -6,3 +6,5 @@ zephyr_library()
 zephyr_library_link_libraries(hw75_proto)
 
 zephyr_library_sources(uart_comm.c)
+
+add_subdirectory(handler)
diff --git a/config/boards/arm/hw75_dynamic/app/uart_comm/handler/CMakeLists.txt b/config/boards/arm/hw75_dynamic/app/uart_comm/handler/CMakeLists.txt
new file mode 100644
index 00000000..219e0319
--- /dev/null
+++ b/config/boards/arm/hw75_dynamic/app/uart_comm/handler/CMakeLists.txt
@@ -0,0 +1,7 @@
+# Copyright (c) 2022-2023 XiNGRZ
+# SPDX-License-Identifier: MIT
+
+# handler - fn-state
+
+zephyr_library_sources(handler_fn_state.c)
+zephyr_library_include_directories(${CMAKE_SOURCE_DIR}/include)
diff --git a/config/boards/arm/hw75_dynamic/app/uart_comm/handler/handler.h b/config/boards/arm/hw75_dynamic/app/uart_comm/handler/handler.h
new file mode 100644
index 00000000..ecc9bab5
--- /dev/null
+++ b/config/boards/arm/hw75_dynamic/app/uart_comm/handler/handler.h
@@ -0,0 +1,12 @@
+/*
+ * Copyright (c) 2022-2023 XiNGRZ
+ * SPDX-License-Identifier: MIT
+ */
+
+#pragma once
+
+#include "uart_comm.pb.h"
+
+typedef bool (*uart_comm_handler_t)(const uart_comm_MessageK2D *k2d);
+
+bool handle_fn_state(const uart_comm_MessageK2D *k2d);
diff --git a/config/boards/arm/hw75_dynamic/app/uart_comm/handler/handler_fn_state.c b/config/boards/arm/hw75_dynamic/app/uart_comm/handler/handler_fn_state.c
new file mode 100644
index 00000000..62b243ca
--- /dev/null
+++ b/config/boards/arm/hw75_dynamic/app/uart_comm/handler/handler_fn_state.c
@@ -0,0 +1,24 @@
+/*
+ * Copyright (c) 2022-2023 XiNGRZ
+ * SPDX-License-Identifier: MIT
+ */
+
+#include "handler.h"
+
+#include <zmk/keymap.h>
+
+static uint8_t current_layer = 0;
+
+bool handle_fn_state(const uart_comm_MessageK2D *k2d)
+{
+	const uart_comm_FnState *report = &k2d->payload.fn_state;
+
+	if (report->pressed) {
+		current_layer = zmk_keymap_highest_layer_active();
+		zmk_keymap_layer_to(1);
+	} else {
+		zmk_keymap_layer_to(current_layer);
+	}
+
+	return true;
+}
diff --git a/config/boards/arm/hw75_dynamic/app/uart_comm/uart_comm.c b/config/boards/arm/hw75_dynamic/app/uart_comm/uart_comm.c
index cef7b51a..3c4943ab 100644
--- a/config/boards/arm/hw75_dynamic/app/uart_comm/uart_comm.c
+++ b/config/boards/arm/hw75_dynamic/app/uart_comm/uart_comm.c
@@ -11,6 +11,10 @@
 #include <logging/log.h>
 LOG_MODULE_REGISTER(uart_comm, CONFIG_HW75_UART_COMM_LOG_LEVEL);
 
+#include <pb_decode.h>
+
+#include "handler/handler.h"
+
 #define SLIP_LABEL DT_LABEL(DT_NODELABEL(slip))
 
 static uint8_t uart_rx_buf[CONFIG_HW75_UART_COMM_MAX_RX_MESSAGE_SIZE];
@@ -20,6 +24,35 @@ struct k_thread thread;
 
 static const struct device *slip;
 
+static struct {
+	uart_comm_Action action;
+	uart_comm_handler_t handler;
+} handlers[] = {
+	{ uart_comm_Action_FN_STATE_CHANGED, handle_fn_state },
+};
+
+static void uart_comm_handle(uint32_t len)
+{
+	LOG_HEXDUMP_DBG(uart_rx_buf, len, "RX");
+
+	pb_istream_t k2d_stream = pb_istream_from_buffer(uart_rx_buf, len);
+
+	uart_comm_MessageK2D k2d = uart_comm_MessageK2D_init_zero;
+	if (!pb_decode_delimited(&k2d_stream, uart_comm_MessageK2D_fields, &k2d)) {
+		LOG_ERR("Failed decoding k2d message: %s", k2d_stream.errmsg);
+		return;
+	}
+
+	LOG_DBG("report action: %d", k2d.action);
+
+	for (size_t i = 0; i < ARRAY_SIZE(handlers); i++) {
+		if (handlers[i].action == k2d.action) {
+			handlers[i].handler(&k2d);
+			break;
+		}
+	}
+}
+
 static void uart_comm_thread(void *p1, void *p2, void *p3)
 {
 	ARG_UNUSED(p1);
@@ -30,7 +63,7 @@ static void uart_comm_thread(void *p1, void *p2, void *p3)
 
 	while (1) {
 		uart_slip_receive(slip, uart_rx_buf, sizeof(uart_rx_buf), &len);
-		LOG_HEXDUMP_DBG(uart_rx_buf, len, "RX");
+		uart_comm_handle(len);
 	}
 }