diff --git a/Tools/AP_Periph/AP_Periph.h b/Tools/AP_Periph/AP_Periph.h
index 1bdb5f3e35220..085a4263f8a8c 100644
--- a/Tools/AP_Periph/AP_Periph.h
+++ b/Tools/AP_Periph/AP_Periph.h
@@ -77,6 +77,9 @@ extern "C" {
 void can_printf(const char *fmt, ...) FMT_PRINTF(1,2);
 }
 
+struct CanardInstance;
+struct CanardRxTransfer;
+
 class AP_Periph_FW {
 public:
     AP_Periph_FW();
@@ -340,6 +343,23 @@ class AP_Periph_FW {
                                  uint8_t priority,
                                  const void* payload,
                                  uint16_t payload_len);
+
+#if AP_UART_MONITOR_ENABLED
+    void handle_tunnel_Targetted(CanardInstance* ins, CanardRxTransfer* transfer);
+    void send_serial_monitor_data();
+    int8_t get_default_tunnel_serial_port(void) const;
+
+    struct {
+        ByteBuffer *buffer;
+        uint32_t last_request_ms;
+        AP_HAL::UARTDriver *uart;
+        int8_t uart_num;
+        uint8_t node_id;
+        uint8_t protocol;
+        uint32_t baudrate;
+        bool locked;
+    } uart_monitor;
+#endif
 };
 
 namespace AP
diff --git a/Tools/AP_Periph/can.cpp b/Tools/AP_Periph/can.cpp
index 1a4fd91eea05a..e4cccc9a68f05 100644
--- a/Tools/AP_Periph/can.cpp
+++ b/Tools/AP_Periph/can.cpp
@@ -968,8 +968,14 @@ static void onTransferReceived(CanardInstance* ins,
         handle_MovingBaselineData(ins, transfer);
         break;
 #endif
+#endif // HAL_PERIPH_ENABLE_GPS
+
+#if AP_UART_MONITOR_ENABLED
+    case UAVCAN_TUNNEL_TARGETTED_ID:
+        periph.handle_tunnel_Targetted(ins, transfer);
+        break;
 #endif
-        
+
 #if defined(AP_PERIPH_HAVE_LED_WITHOUT_NOTIFY) || defined(HAL_PERIPH_ENABLE_NOTIFY)
     case UAVCAN_EQUIPMENT_INDICATION_LIGHTSCOMMAND_ID:
         handle_lightscommand(ins, transfer);
@@ -1068,7 +1074,14 @@ static bool shouldAcceptTransfer(const CanardInstance* ins,
         *out_data_type_signature = ARDUPILOT_GNSS_MOVINGBASELINEDATA_SIGNATURE;
         return true;
 #endif
+#endif // HAL_PERIPH_ENABLE_GPS
+
+#if AP_UART_MONITOR_ENABLED
+    case UAVCAN_TUNNEL_TARGETTED_ID:
+        *out_data_type_signature = UAVCAN_TUNNEL_TARGETTED_SIGNATURE;
+        return true;
 #endif
+
 #ifdef HAL_PERIPH_ENABLE_RC_OUT
     case UAVCAN_EQUIPMENT_ESC_RAWCOMMAND_ID:
         *out_data_type_signature = UAVCAN_EQUIPMENT_ESC_RAWCOMMAND_SIGNATURE;
@@ -1845,6 +1858,9 @@ void AP_Periph_FW::can_update()
     {
         can_mag_update();
         can_gps_update();
+#if AP_UART_MONITOR_ENABLED
+        send_serial_monitor_data();
+#endif
         can_battery_update();
         can_baro_update();
         can_airspeed_update();
diff --git a/Tools/AP_Periph/serial_tunnel.cpp b/Tools/AP_Periph/serial_tunnel.cpp
new file mode 100644
index 0000000000000..be38a35125839
--- /dev/null
+++ b/Tools/AP_Periph/serial_tunnel.cpp
@@ -0,0 +1,211 @@
+/*
+   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, either version 3 of the License, or
+   (at your option) any later version.
+
+   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/>.
+ */
+/*
+  handle tunnelling of serial data over DroneCAN
+ */
+
+#include <AP_HAL/AP_HAL_Boards.h>
+#include "AP_Periph.h"
+
+#if AP_UART_MONITOR_ENABLED
+
+#include <dronecan_msgs.h>
+
+extern const AP_HAL::HAL &hal;
+
+#define TUNNEL_LOCK_KEY 0xf2e460e4U
+
+#ifndef TUNNEL_DEBUG
+#define TUNNEL_DEBUG 0
+#endif
+
+#if TUNNEL_DEBUG
+# define debug(fmt, args...) can_printf(fmt "\n", ##args)
+#else
+# define debug(fmt, args...)
+#endif
+
+/*
+  get the default port to tunnel if the client requests port -1
+ */
+int8_t AP_Periph_FW::get_default_tunnel_serial_port(void) const
+{
+    int8_t uart_num = -1;
+#ifdef HAL_PERIPH_ENABLE_GPS
+    if (uart_num == -1) {
+        uart_num = g.gps_port;
+    }
+#endif
+#ifdef HAL_PERIPH_ENABLE_RANGEFINDER
+    if (uart_num == -1) {
+        uart_num = g.rangefinder_port;
+    }
+#endif
+#ifdef HAL_PERIPH_ENABLE_ADSB
+    if (uart_num == -1) {
+        uart_num = g.adsb_port;
+    }
+#endif
+#if HAL_PROXIMITY_ENABLED
+    if (uart_num == -1) {
+        uart_num = g.proximity_port;
+    }
+#endif
+    return uart_num;
+}
+
+/*
+  handle tunnel data
+ */
+void AP_Periph_FW::handle_tunnel_Targetted(CanardInstance* ins, CanardRxTransfer* transfer)
+{
+    uavcan_tunnel_Targetted pkt;
+    if (uavcan_tunnel_Targetted_decode(transfer, &pkt)) {
+        return;
+    }
+    if (pkt.target_node != canardGetLocalNodeID(ins)) {
+        return;
+    }
+    if (uart_monitor.buffer == nullptr) {
+        uart_monitor.buffer = new ByteBuffer(1024);
+        if (uart_monitor.buffer == nullptr) {
+            return;
+        }
+    }
+    int8_t uart_num = pkt.serial_id;
+    if (uart_num == -1) {
+        uart_num = get_default_tunnel_serial_port();
+    }
+    if (uart_num < 0) {
+        return;
+    }
+    auto *uart = hal.serial(uart_num);
+    if (uart == nullptr) {
+        return;
+    }
+    if (uart_monitor.uart_num != uart_num && uart_monitor.uart != nullptr) {
+        // remove monitor from previous uart
+        hal.serial(uart_monitor.uart_num)->set_monitor_read_buffer(nullptr);
+    }
+    uart_monitor.uart_num = uart_num;
+    if (uart != uart_monitor.uart) {
+        // change of uart or expired, clear old data
+        uart_monitor.buffer->clear();
+        uart_monitor.uart = uart;
+        uart_monitor.baudrate = 0;
+    }
+    if (uart_monitor.uart == nullptr) {
+        return;
+    }
+    /*
+      allow for locked state to change at any time, so users can
+      switch between locked and unlocked while connected
+     */
+    uart_monitor.locked = (pkt.options & UAVCAN_TUNNEL_TARGETTED_OPTION_LOCK_PORT) != 0;
+    if (uart_monitor.locked) {
+        uart_monitor.uart->lock_port(TUNNEL_LOCK_KEY, TUNNEL_LOCK_KEY);
+    } else {
+        uart_monitor.uart->lock_port(0,0);
+    }
+    uart_monitor.node_id = transfer->source_node_id;
+    uart_monitor.protocol = pkt.protocol.protocol;
+    if (pkt.baudrate != uart_monitor.baudrate) {
+        if (uart_monitor.locked && pkt.baudrate != 0) {
+            uart_monitor.uart->begin_locked(pkt.baudrate, 0, 0, TUNNEL_LOCK_KEY);
+            debug("begin_locked %u", unsigned(pkt.baudrate));
+        }
+        uart_monitor.baudrate = pkt.baudrate;
+    }
+    uart_monitor.uart->set_monitor_read_buffer(uart_monitor.buffer);
+    uart_monitor.last_request_ms = AP_HAL::millis();
+
+    // write to device
+    if (pkt.buffer.len > 0) {
+        if (uart_monitor.locked) {
+            debug("write_locked %u", unsigned(pkt.buffer.len));
+            uart_monitor.uart->write_locked(pkt.buffer.data, pkt.buffer.len, TUNNEL_LOCK_KEY);
+        } else {
+            uart_monitor.uart->write(pkt.buffer.data, pkt.buffer.len);
+        }
+    } else {
+        debug("locked keepalive");
+    }
+}
+
+/*
+  send tunnelled serial data
+ */
+void AP_Periph_FW::send_serial_monitor_data()
+{
+    if (uart_monitor.uart == nullptr ||
+        uart_monitor.node_id == 0 ||
+        uart_monitor.buffer == nullptr) {
+        return;
+    }
+    const uint32_t last_req_ms = uart_monitor.last_request_ms;
+    const uint32_t now_ms = AP_HAL::millis();
+    if (now_ms - last_req_ms >= 3000) {
+        // stop sending and unlock, but don't release the buffer
+        if (uart_monitor.locked) {
+            debug("unlock");
+            uart_monitor.uart->lock_port(0, 0);
+        }
+        uart_monitor.uart = nullptr;
+        return;
+    }
+    if (uart_monitor.locked) {
+        /*
+          when the port is locked nobody is reading the uart so the
+          monitor doesn't fill. We read here to ensure it fills
+         */
+        uint8_t buf[120];
+        for (uint8_t i=0; i<8; i++) {
+            if (uart_monitor.uart->read_locked(buf, sizeof(buf), TUNNEL_LOCK_KEY) <= 0) {
+                break;
+            }
+        }
+    }
+    uint8_t sends = 8;
+    while (uart_monitor.buffer->available() > 0 && sends-- > 0) {
+        uint32_t n;
+        const uint8_t *buf = uart_monitor.buffer->readptr(n);
+        if (n == 0) {
+            return;
+        }
+        // broadcast data as tunnel packets, can be used for uCenter debug and device fw update
+        uavcan_tunnel_Targetted pkt {};
+        n = MIN(n, sizeof(pkt.buffer.data));
+        pkt.target_node = uart_monitor.node_id;
+        pkt.protocol.protocol = uart_monitor.protocol;
+        pkt.buffer.len = n;
+        pkt.baudrate = uart_monitor.baudrate;
+        memcpy(pkt.buffer.data, buf, n);
+
+        uint8_t buffer[UAVCAN_TUNNEL_TARGETTED_MAX_SIZE] {};
+        const uint16_t total_size = uavcan_tunnel_Targetted_encode(&pkt, buffer, !canfdout());
+
+        debug("read %u", unsigned(n));
+
+        if (!canard_broadcast(UAVCAN_TUNNEL_TARGETTED_SIGNATURE,
+                              UAVCAN_TUNNEL_TARGETTED_ID,
+                              CANARD_TRANSFER_PRIORITY_MEDIUM,
+                              &buffer[0],
+                              total_size)) {
+            break;
+        }
+        uart_monitor.buffer->advance(n);
+    }
+}
+#endif // AP_UART_MONITOR_ENABLED
diff --git a/Tools/ardupilotwaf/boards.py b/Tools/ardupilotwaf/boards.py
index 7b8a302679477..98005453a6061 100644
--- a/Tools/ardupilotwaf/boards.py
+++ b/Tools/ardupilotwaf/boards.py
@@ -803,6 +803,7 @@ def configure_env(self, cfg, env):
             CAN_APP_NODE_NAME = '"org.ardupilot.ap_periph_gps"',
             AP_AIRSPEED_ENABLED = 0,
             HAL_PERIPH_ENABLE_GPS = 1,
+            AP_UART_MONITOR_ENABLED = 1,
             HAL_CAN_DEFAULT_NODE_ID = 0,
             HAL_RAM_RESERVE_START = 0,
             APJ_BOARD_ID = 100,