diff --git a/main/CMakeLists.txt b/main/CMakeLists.txt
index 3f9ede8..a35874f 100644
--- a/main/CMakeLists.txt
+++ b/main/CMakeLists.txt
@@ -1,4 +1,5 @@
 idf_component_register(SRCS "esp_tunnel.cpp"
                             "app_networking.cpp"
                             "app_serial.cpp"
+                            "app_config.cpp"
                     INCLUDE_DIRS ".")
diff --git a/main/Kconfig.projbuild b/main/Kconfig.projbuild
index 34f9584..a3e708d 100644
--- a/main/Kconfig.projbuild
+++ b/main/Kconfig.projbuild
@@ -12,7 +12,6 @@ menu "EspTunnel Configuration"
         help
             ESPNOW local master key. Must be 16 bytes.
 
-
     config ESPTNL_CHANNEL
         int "Channel"
         default 1
@@ -20,4 +19,10 @@ menu "EspTunnel Configuration"
         help
             The channel for sending and receiving ESPNOW data.
 
+    config ESPTNL_UART
+        int "UART interface"
+        default 0
+        help
+            The UART interface to use for RX and TX.
+
 endmenu
\ No newline at end of file
diff --git a/main/app_config.cpp b/main/app_config.cpp
new file mode 100644
index 0000000..046240d
--- /dev/null
+++ b/main/app_config.cpp
@@ -0,0 +1,24 @@
+//
+// Created by erki on 11/06/23.
+//
+
+#include <cstdint>
+
+#include "esp_now.h"
+#include "driver/uart.h"
+
+namespace
+{
+
+template<std::size_t N>
+constexpr auto STR_LEN(const char (&s)[N])
+{
+  return N;
+}
+
+static_assert(STR_LEN(CONFIG_ESPTNL_PMK) == ESP_NOW_KEY_LEN + 1, "CONFIG_ESPTNL_PMK must be of length 16 bytes + 1 null terminator.");
+static_assert(STR_LEN(CONFIG_ESPTNL_LMK) == ESP_NOW_KEY_LEN + 1, "CONFIG_ESPTNL_LMK must be of length 16 bytes + 1 null terminator.");
+
+static_assert(CONFIG_ESPTNL_UART < UART_NUM_MAX && CONFIG_ESPTNL_UART >= 0, "CONFIG_ESPTNL_UART must be within range [0, UART_NUM_MAX[.");
+
+}
diff --git a/main/app_networking.cpp b/main/app_networking.cpp
index 76a0076..6d96c4d 100644
--- a/main/app_networking.cpp
+++ b/main/app_networking.cpp
@@ -22,15 +22,6 @@ static const char* TAG = "Networking";
 static_assert(std::is_standard_layout_v<EspNowEvent> && std::is_trivial_v<EspNowEvent>,
         "EspNowEvent is not compatible with a FreeRTOS queue.");
 
-template<std::size_t N>
-constexpr auto STR_LEN(const char (&s)[N])
-{
-  return N;
-}
-
-static_assert(STR_LEN(CONFIG_ESPTNL_PMK) == ESP_NOW_KEY_LEN + 1, "CONFIG_ESPTNL_PMK must be of length 16 bytes + 1 null terminator.");
-static_assert(STR_LEN(CONFIG_ESPTNL_LMK) == ESP_NOW_KEY_LEN + 1, "CONFIG_ESPTNL_LMK must be of length 16 bytes + 1 null terminator.");
-
 QueueHandle_t s_esp_now_queue = nullptr;
 std::array<std::uint8_t, 128> s_rx_buffer;
 std::variant<MacAddress, std::monostate> s_peer;
diff --git a/main/app_serial.cpp b/main/app_serial.cpp
index 27749b5..d964d87 100644
--- a/main/app_serial.cpp
+++ b/main/app_serial.cpp
@@ -16,7 +16,7 @@ QueueHandle_t s_uart_queue = nullptr;
 namespace Serial
 {
 
-QueueHandle_t setupSerial()
+QueueHandle_t setupSerial(const uart_port_t uart)
 {
   uart_config_t config = {
     .baud_rate = 115200,
@@ -27,9 +27,9 @@ QueueHandle_t setupSerial()
     .source_clk = UART_SCLK_DEFAULT,
   };
 
-  ESP_ERROR_CHECK(uart_driver_install(UART_NUM_0, 132, 128 * 2, 4, &s_uart_queue, 0));
-  ESP_ERROR_CHECK(uart_param_config(UART_NUM_0, &config));
-  ESP_ERROR_CHECK(uart_set_pin(UART_NUM_0, UART_PIN_NO_CHANGE, UART_PIN_NO_CHANGE, UART_PIN_NO_CHANGE, UART_PIN_NO_CHANGE));
+  ESP_ERROR_CHECK(uart_driver_install(uart, 132, 128 * 2, 4, &s_uart_queue, 0));
+  ESP_ERROR_CHECK(uart_param_config(uart, &config));
+  ESP_ERROR_CHECK(uart_set_pin(uart, UART_PIN_NO_CHANGE, UART_PIN_NO_CHANGE, UART_PIN_NO_CHANGE, UART_PIN_NO_CHANGE));
 
   return s_uart_queue;
 }
diff --git a/main/app_serial.hpp b/main/app_serial.hpp
index 29fed6b..cd21bac 100644
--- a/main/app_serial.hpp
+++ b/main/app_serial.hpp
@@ -6,10 +6,11 @@
 
 #include "freertos/FreeRTOS.h"
 #include "freertos/queue.h"
+#include "driver/uart.h"
 
 namespace Serial
 {
 
-[[nodiscard]] QueueHandle_t setupSerial();
+[[nodiscard]] QueueHandle_t setupSerial(const uart_port_t uart);
 
 }
diff --git a/main/esp_tunnel.cpp b/main/esp_tunnel.cpp
index b03061d..1a0721d 100644
--- a/main/esp_tunnel.cpp
+++ b/main/esp_tunnel.cpp
@@ -30,7 +30,7 @@ void s_sendUartData(const std::size_t len)
   ESP_LOGD(TAG, "Sending %u bytes via UART.", len);
 
   std::array<std::uint8_t, 128> tx_buffer;
-  uart_read_bytes(UART_NUM_0, tx_buffer.data(), len, 0);
+  uart_read_bytes(CONFIG_ESPTNL_UART, tx_buffer.data(), len, 0);
 
   Networking::sendData(tx_buffer, len);
 }
@@ -38,7 +38,7 @@ void s_sendUartData(const std::size_t len)
 std::size_t s_uartBytesWaiting()
 {
   std::size_t len = 0;
-  uart_get_buffered_data_len(UART_NUM_0, &len);
+  uart_get_buffered_data_len(CONFIG_ESPTNL_UART, &len);
   return std::min<std::size_t>(len, 128);
 }
 
@@ -60,12 +60,12 @@ std::size_t s_uartBytesWaiting()
       if (event.type == Networking::EspNowEvent::MSG_RECEIVED)
       {
         std::size_t uart_free = 0;
-        uart_get_tx_buffer_free_size(UART_NUM_0, &uart_free);
+        uart_get_tx_buffer_free_size(CONFIG_ESPTNL_UART, &uart_free);
         if (uart_free >= event.rx_length)
         {
           ESP_LOGD(TAG, "ESP-NOW event: wrote %ull bytes to UART RX.", uart_free);
           const auto& esp_rx_buffer = Networking::getRxBuffer();
-          uart_write_bytes(UART_NUM_0, esp_rx_buffer.data(), event.rx_length);
+          uart_write_bytes(CONFIG_ESPTNL_UART, esp_rx_buffer.data(), event.rx_length);
         }
         else
         {
@@ -124,7 +124,7 @@ extern "C" void app_main(void)
 
   Networking::setupWifi();
   s_esp_now_queue = Networking::setupEspNow();
-  s_uart_queue = Serial::setupSerial();
+  s_uart_queue = Serial::setupSerial(CONFIG_ESPTNL_UART);
 
   s_timer = xTimerCreate("autosend_timer", pdMS_TO_TICKS(100), false, nullptr, s_cbListenTimeout);