diff --git a/include/ble_midi_transport.h b/include/ble_midi_transport.h
index e48614d..847635e 100644
--- a/include/ble_midi_transport.h
+++ b/include/ble_midi_transport.h
@@ -20,12 +20,12 @@ public:
 
     bool is_connected();
 
+    void send_midi_packet(const uint8_t* data, uint8_t len);
+    void on_receive(const uint8_t* data, size_t len);
+    size_t parse_ble_midi(uint8_t status, const uint8_t* data, size_t len, size_t offset, MidiEvent& event);
+
 private:
     std::function<void(const MidiEvent&)> receive_callback;
     bool initialized;
     bool client_connected;
-
-    void send_midi_packet(const uint8_t* data, uint8_t len);
-    void on_receive(const uint8_t* data, size_t len);
-    size_t parse_ble_midi(uint8_t status, const uint8_t* data, size_t len, size_t offset, MidiEvent& event);
 };
diff --git a/src/ble_midi_transport.cpp b/src/ble_midi_transport.cpp
index dcc2e00..d100ba1 100644
--- a/src/ble_midi_transport.cpp
+++ b/src/ble_midi_transport.cpp
@@ -104,19 +104,19 @@ void BleMidiTransport::send_midi_packet(const uint8_t* data, uint8_t len) {
 }
 
 void BleMidiTransport::send_note_on(uint8_t channel, uint8_t note, uint8_t velocity) {
-    uint8_t packet[3] = {0x90 | (channel - 1), note, velocity};
+    uint8_t packet[3] = {(uint8_t)(0x90 | (channel - 1)), note, velocity};
     send_midi_packet(packet, 3);
     Serial.printf("[BLE OUT] Ch:%d NOTE_ON:%d:%d\n", channel, note, velocity);
 }
 
 void BleMidiTransport::send_note_off(uint8_t channel, uint8_t note, uint8_t velocity) {
-    uint8_t packet[3] = {0x80 | (channel - 1), note, velocity};
+    uint8_t packet[3] = {(uint8_t)(0x80 | (channel - 1)), note, velocity};
     send_midi_packet(packet, 3);
     Serial.printf("[BLE OUT] Ch:%d NOTE_OFF:%d:%d\n", channel, note, velocity);
 }
 
 void BleMidiTransport::send_cc(uint8_t channel, uint8_t cc, uint8_t value) {
-    uint8_t packet[3] = {0xB0 | (channel - 1), cc, value};
+    uint8_t packet[3] = {(uint8_t)(0xB0 | (channel - 1)), cc, value};
     send_midi_packet(packet, 3);
     Serial.printf("[BLE OUT] Ch:%d CC:%d:%d\n", channel, cc, value);
 }