BLE MIDIの通信
ESP32とWindows10の間でBLE MIDI通信したときに，頻度がどうなるか調べてみた．参考にしたのは
- プログラム全体：ここからたどったこのプログラム
- タイムスタンプの付け方：このプログラム
- コネクションインターバルの設定方法：onConect()内で設定
結果
- ESP32側で13.333ms毎にnotify()した 全て届いた
- onConnect()内でconn_params.max_int を0x20にすると40ms毎に、0x0cにすると15ms毎に届く（値 * 1.25ms）それより小さい値を設定しても15msより短くはならないみたい 設定値より遅れることもある
- 同じ時刻に届く（MIDI-OXに認識される）こともある
===> MIDI-OX Version: 7.0.2.372 ===> Log Opened: Tue 30-Jun-2020 11:56:51 ===> TIMESTAMP IN PORT STATUS DATA1 DATA2 CHAN NOTE EVENT 20 1 -- 176 2 49 1 --- CC: Breath 35 1 -- 176 2 50 1 --- CC: Breath 51 1 -- 176 2 51 1 --- CC: Breath 65 1 -- 176 2 52 1 --- CC: Breath 66 1 -- 176 2 53 1 --- CC: Breath 80 1 -- 176 2 54 1 --- CC: Breath 95 1 -- 176 2 55 1 --- CC: Breath 110 1 -- 176 2 56 1 --- CC: Breath 125 1 -- 176 2 57 1 --- CC: Breath 140 1 -- 176 2 58 1 --- CC: Breath 155 1 -- 176 2 59 1 --- CC: Breath 170 1 -- 176 2 60 1 --- CC: Breath 185 1 -- 176 2 61 1 --- CC: Breath 200 1 -- 176 2 62 1 --- CC: Breath 201 1 -- 176 2 63 1 --- CC: Breath 215 1 -- 176 2 64 1 --- CC: Breath 230 1 -- 176 2 65 1 --- CC: Breath 245 1 -- 176 2 66 1 --- CC: Breath 260 1 -- 176 2 67 1 --- CC: Breath 275 1 -- 176 2 68 1 --- CC: Breath 290 1 -- 176 2 69 1 --- CC: Breath 305 1 -- 176 2 70 1 --- CC: Breath 320 1 -- 176 2 71 1 --- CC: Breath 335 1 -- 176 2 72 1 --- CC: Breath 335 1 -- 176 2 73 1 --- CC: Breath 350 1 -- 176 2 74 1 --- CC: Breath 365 1 -- 176 2 0 1 --- CC: Breath 380 1 -- 176 2 1 1 --- CC: Breath 395 1 -- 176 2 2 1 --- CC: Breath 410 1 -- 176 2 3 1 --- CC: Breath 426 1 -- 176 2 4 1 --- CC: Breath 440 1 -- 176 2 5 1 --- CC: Breath 455 1 -- 176 2 6 1 --- CC: Breath 470 1 -- 176 2 7 1 --- CC: Breath 470 1 -- 176 2 8 1 --- CC: Breath 485 1 -- 176 2 9 1 --- CC: Breath 500 1 -- 176 2 10 1 --- CC: Breath 515 1 -- 176 2 11 1 --- CC: Breath 530 1 -- 176 2 12 1 --- CC: Breath 545 1 -- 176 2 13 1 --- CC: Breath 560 1 -- 176 2 14 1 --- CC: Breath 575 1 -- 176 2 15 1 --- CC: Breath 590 1 -- 176 2 16 1 --- CC: Breath 605 1 -- 176 2 17 1 --- CC: Breath 606 1 -- 176 2 18 1 --- CC: Breath 620 1 -- 176 2 19 1 --- CC: Breath 636 1 -- 176 2 20 1 --- CC: Breath 650 1 -- 176 2 21 1 --- CC: Breath 665 1 -- 176 2 22 1 --- CC: Breath 680 1 -- 176 2 23 1 --- CC: Breath 695 1 -- 176 2 24 1 --- CC: Breath 710 1 -- 176 2 25 1 --- CC: Breath 725 1 -- 176 2 26 1 --- CC: Breath 740 1 -- 176 2 27 1 --- CC: Breath 741 1 -- 176 2 28 1 --- CC: Breath 755 1 -- 176 2 29 1 --- CC: Breath 770 1 -- 176 2 30 1 --- CC: Breath 785 1 -- 176 2 31 1 --- CC: Breath 800 1 -- 176 2 32 1 --- CC: Breath 815 1 -- 176 2 33 1 --- CC: Breath 838 1 -- 176 2 34 1 --- CC: Breath 845 1 -- 176 2 35 1 --- CC: Breath 862 1 -- 176 2 36 1 --- CC: Breath 875 1 -- 176 2 37 1 --- CC: Breath 875 1 -- 176 2 38 1 --- CC: Breath 890 1 -- 176 2 39 1 --- CC: Breath 905 1 -- 176 2 40 1 --- CC: Breath 920 1 -- 176 2 41 1 --- CC: Breath 935 1 -- 176 2 42 1 --- CC: Breath 950 1 -- 176 2 43 1 --- CC: Breath 965 1 -- 176 2 44 1 --- CC: Breath 980 1 -- 176 2 45 1 --- CC: Breath 995 1 -- 176 2 46 1 --- CC: Breath 1010 1 -- 176 2 47 1 --- CC: Breath 1011 1 -- 176 2 48 1 --- CC: Breath 1025 1 -- 176 2 49 1 --- CC: Breath 1040 1 -- 176 2 50 1 --- CC: Breath 1055 1 -- 176 2 51 1 --- CC: Breath 1070 1 -- 176 2 52 1 --- CC: Breath 1085 1 -- 176 2 53 1 --- CC: Breath 1100 1 -- 176 2 54 1 --- CC: Breath 1115 1 -- 176 2 55 1 --- CC: Breath 1130 1 -- 176 2 56 1 --- CC: Breath 1145 1 -- 176 2 57 1 --- CC: Breath 1145 1 -- 176 2 58 1 --- CC: Breath 1160 1 -- 176 2 59 1 --- CC: Breath 1175 1 -- 176 2 60 1 --- CC: Breath 1190 1 -- 176 2 61 1 --- CC: Breath 1205 1 -- 176 2 62 1 --- CC: Breath 1227 1 -- 176 2 63 1 --- CC: Breath 1235 1 -- 176 2 64 1 --- CC: Breath 1250 1 -- 176 2 65 1 --- CC: Breath 1265 1 -- 176 2 66 1 --- CC: Breath 1280 1 -- 176 2 67 1 --- CC: Breath 1281 1 -- 176 2 68 1 --- CC: Breath 1295 1 -- 176 2 69 1 --- CC: Breath 1310 1 -- 176 2 70 1 --- CC: Breath 1325 1 -- 176 2 71 1 --- CC: Breath 1340 1 -- 176 2 72 1 --- CC: Breath 1355 1 -- 176 2 73 1 --- CC: Breath 1371 1 -- 176 2 74 1 --- CC: Breath 1385 1 -- 176 2 0 1 --- CC: Breath 1400 1 -- 176 2 1 1 --- CC: Breath 1415 1 -- 176 2 2 1 --- CC: Breath 1415 1 -- 176 2 3 1 --- CC: Breath 1430 1 -- 176 2 4 1 --- CC: Breath 1445 1 -- 176 2 5 1 --- CC: Breath 1460 1 -- 176 2 6 1 --- CC: Breath 1475 1 -- 176 2 7 1 --- CC: Breath
#include <BLEDevice.h> #include <BLEUtils.h> #include <BLEServer.h> #include <BLE2902.h> #define SERVICE_UUID "03b80e5a-ede8-4b33-a751-6ce34ec4c700" #define CHARACTERISTIC_UUID "7772e5db-3868-4112-a1a9-f2669d106bf3" BLECharacteristic *pCharacteristic; bool deviceConnected = false; uint8_t midiPacket[] = { 0x80, // header 0x80, // timestamp, not implemented 0x00, // status 0x3c, // 0x3c == 60 == middle c 0x00 // velocity }; void setup() { delay(500); Serial.begin(115200); BLE_init(); } void loop() { noteOn(60, 120); for (;;) { for (int i=0; i<75; i++) { setBreath(i); delayMicroseconds(13333); // 75Hz } } } void setBreath(int value) { setTimestamp(); midiPacket[2] = 0xB0; // control change midiPacket[3] = 2; // breath midiPacket[4] = value; // value pCharacteristic->setValue(midiPacket, 5); // packet, length in bytes pCharacteristic->notify(); } void setTimestamp() { auto currentTimestamp = millis() & 0x01fff; midiPacket[0] = ((currentTimestamp >> 7) & 0x3f) | 0x80; midiPacket[1] = (currentTimestamp & 0x7f) | 0x80; } class MyServerCallbacks: public BLEServerCallbacks { void onConnect(BLEServer* pServer) { deviceConnected = true; Serial.println("con0"); }; void onConnect(BLEServer* pServer, esp_ble_gatts_cb_param_t* param) { Serial.println("con1"); esp_ble_conn_update_params_t conn_params = {0}; memcpy(conn_params.bda, param->connect.remote_bda, sizeof(esp_bd_addr_t)); conn_params.latency = 0; conn_params.max_int = 0x0c; // max_int = 0x0c*1.25ms = 15ms conn_params.min_int = 0x06; // min_int = 0x06*1.25ms = 7.5ms conn_params.timeout = 400; // timeout = 400*10ms = 4000ms //start sent the update connection parameters to the peer device. esp_ble_gap_update_conn_params(&conn_params); } void onDisconnect(BLEServer* pServer) { Serial.println("discon"); deviceConnected = false; } }; void BLE_init() { BLEDevice::init("ESP32 MIDI Example"); // Create the BLE Server BLEServer *pServer = BLEDevice::createServer(); pServer->setCallbacks(new MyServerCallbacks()); // Create the BLE Service BLEService *pService = pServer->createService(BLEUUID(SERVICE_UUID)); // Create a BLE Characteristic pCharacteristic = pService->createCharacteristic( BLEUUID(CHARACTERISTIC_UUID), BLECharacteristic::PROPERTY_READ | BLECharacteristic::PROPERTY_WRITE | BLECharacteristic::PROPERTY_NOTIFY | BLECharacteristic::PROPERTY_WRITE_NR ); // Create a BLE Descriptor pCharacteristic->addDescriptor(new BLE2902()); // Start the service pService->start(); // Start advertising BLEAdvertising *pAdvertising = pServer->getAdvertising(); pAdvertising->addServiceUUID(pService->getUUID()); pAdvertising->start(); }
