Merge pull request #10 from arik-caspi/BLE-Midi-Client
Adding Support for BLE Midi Client
This commit is contained in:
lathoub
GitHub
commit
940c1aa886
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@ -0,0 +1,524 @@
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#pragma once
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// Headers for ESP32 BLE
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#include <BLEDevice.h>
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#include <BLEUtils.h>
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#include <BLEServer.h>
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#include <BLE2902.h>
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//#include "BLEScan.h"
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#include "Arduino.h"
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#include "common/midiCommon.h"
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using namespace Midi;
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BEGIN_BLEMIDI_NAMESPACE
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static bool isDataReceived = false;
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static bool doScan = false;
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static BLEScan* pBLEScan;
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static void notifyCallback(
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BLERemoteCharacteristic* pBLERemoteCharacteristic,
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uint8_t* pData,
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size_t length,
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bool isNotify)
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{
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isDataReceived = true;
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}
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static void scanCompleteCB(BLEScanResults scanResults)
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{
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scanResults.dump();
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if (doScan)
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{
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pBLEScan->start(10, scanCompleteCB);
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}
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}
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class MyClientCallbacks;
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class BleMidiInterfaceClient : public MidiCommonInterface
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{
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protected:
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// ESP32
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BLEClient * pClient;
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//BLEAdvertising * _advertising;
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//BLECharacteristic *_characteristic;
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uint8_t _midiPacket[5]; // outgoing
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public:
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void * operator new(size_t size)
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{
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void * p = heap_caps_malloc(size, MALLOC_CAP_SPIRAM);
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return p;
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}
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// callbacks
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void(*_connectedCallback)() = NULL;
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void(*_disconnectedCallback)() = NULL;
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char _deviceName[32];
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bool _doConnect;
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BLEAdvertisedDevice * _advertising;
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BLERemoteService* pRemoteService;
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BLERemoteCharacteristic* pRemoteCharacteristic;
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bool _connected;
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protected:
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inline static void getMidiTimestamp (uint8_t *header, uint8_t *timestamp)
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{
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/*
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The first byte of all BLE packets must be a header byte. This is followed by timestamp bytes and MIDI messages.
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Header Byte
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bit 7 Set to 1.
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bit 6 Set to 0. (Reserved for future use)
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bits 5-0 timestampHigh:Most significant 6 bits of timestamp information.
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The header byte contains the topmost 6 bits of timing information for MIDI events in the BLE
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packet. The remaining 7 bits of timing information for individual MIDI messages encoded in a
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packet is expressed by timestamp bytes.
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Timestamp Byte
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bit 7 Set to 1.
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bits 6-0 timestampLow: Least Significant 7 bits of timestamp information.
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The 13-bit timestamp for the first MIDI message in a packet is calculated using 6 bits from the
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header byte and 7 bits from the timestamp byte.
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Timestamps are 13-bit values in milliseconds, and therefore the maximum value is 8,191 ms.
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Timestamps must be issued by the sender in a monotonically increasing fashion.
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timestampHigh is initially set using the lower 6 bits from the header byte while the timestampLow is
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formed of the lower 7 bits from the timestamp byte. Should the timestamp value of a subsequent
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MIDI message in the same packet overflow/wrap (i.e., the timestampLow is smaller than a
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preceding timestampLow), the receiver is responsible for tracking this by incrementing the
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timestampHigh by one (the incremented value is not transmitted, only understood as a result of the
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overflow condition).
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In practice, the time difference between MIDI messages in the same BLE packet should not span
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more than twice the connection interval. As a result, a maximum of one overflow/wrap may occur
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per BLE packet.
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Timestamps are in the sender’s clock domain and are not allowed to be scheduled in the future.
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Correlation between the receiver’s clock and the received timestamps must be performed to
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ensure accurate rendering of MIDI messages, and is not addressed in this document.
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*/
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/*
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Calculating a Timestamp
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To calculate the timestamp, the built-in millis() is used.
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The BLE standard only specifies 13 bits worth of millisecond data though,
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so it’s bitwise anded with 0x1FFF for an ever repeating cycle of 13 bits.
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This is done right after a MIDI message is detected. It’s split into a 6 upper bits, 7 lower bits,
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and the MSB of both bytes are set to indicate that this is a header byte.
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Both bytes are placed into the first two position of an array in preparation for a MIDI message.
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*/
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auto currentTimeStamp = millis() & 0x01FFF;
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*header = ((currentTimeStamp >> 7) & 0x3F) | 0x80; // 6 bits plus MSB
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*timestamp = (currentTimeStamp & 0x7F) | 0x80; // 7 bits plus MSB
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}
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// serialize towards hardware
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void write(DataByte b1)
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{
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getMidiTimestamp(&_midiPacket[0], &_midiPacket[1]);
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_midiPacket[2] = b1;
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// TODO: quid running status
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if(pRemoteCharacteristic && pRemoteCharacteristic->canWrite())
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{
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pRemoteCharacteristic->writeValue(_midiPacket, 3);
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}
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};
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void write(DataByte b1, DataByte b2)
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{
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getMidiTimestamp(&_midiPacket[0], &_midiPacket[1]);
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_midiPacket[2] = b1;
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_midiPacket[3] = b2;
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// TODO: quid running status
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if(pRemoteCharacteristic && pRemoteCharacteristic->canWrite())
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{
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pRemoteCharacteristic->writeValue(_midiPacket, 4);
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}
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};
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void write(DataByte b1, DataByte b2, DataByte b3)
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{
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getMidiTimestamp(&_midiPacket[0], &_midiPacket[1]);
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_midiPacket[2] = b1;
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_midiPacket[3] = b2;
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_midiPacket[4] = b3;
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// TODO: quid running status
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if(pRemoteCharacteristic && pRemoteCharacteristic->canWrite())
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{
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pRemoteCharacteristic->writeValue(_midiPacket, 5);
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}
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};
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bool connectToServer()
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{
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// Connect to the remote BLE Server.
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pClient->connect(_advertising); // if you pass BLEAdvertisedDevice instead of address, it will be recognized type of peer device address (public or private)
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// Obtain a reference to the service we are after in the remote BLE server.
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pRemoteService = pClient->getService(BLEUUID(SERVICE_UUID));
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if (pRemoteService == nullptr)
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{
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pClient->disconnect();
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return false;
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}
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// Obtain a reference to the characteristic in the service of the remote BLE server.
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pRemoteCharacteristic = pRemoteService->getCharacteristic(BLEUUID(CHARACTERISTIC_UUID));
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if (pRemoteCharacteristic == nullptr)
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{
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pClient->disconnect();
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return false;
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}
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return true;
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};
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public:
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BleMidiInterfaceClient()
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{
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}
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~BleMidiInterfaceClient()
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{
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}
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// TODO why must these functions be inline??
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inline bool begin(const char* deviceName);
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inline void read()
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{
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// If the flag "doConnect" is true then we have scanned for and found the desired
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// BLE Server with which we wish to connect. Now we connect to it. Once we are
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// connected we set the connected flag to be true.
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if (_doConnect == true)
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{
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if (connectToServer())
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{
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// ("We are now connected to the BLE Server.");
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if (nullptr != pRemoteCharacteristic)
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{
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pRemoteCharacteristic->registerForNotify(notifyCallback);
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}
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}
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else
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{
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// ("We have failed to connect to the server; there is nothin more we will do.");
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doScan = true;
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pBLEScan->start(10, scanCompleteCB);
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}
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_doConnect = false;
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}
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if (false == _connected)
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{
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return;
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}
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if (nullptr == pRemoteCharacteristic)
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{
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return;
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}
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// Read the value of the characteristic.
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//if(pRemoteCharacteristic->canRead())
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if (isDataReceived)
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{
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std::string rxValue = pRemoteCharacteristic->readValue();
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if (rxValue.length() > 0)
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{
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this->receive((uint8_t *)(rxValue.c_str()), rxValue.length());
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}
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isDataReceived = false;
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}
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}
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inline void sendMIDI(StatusByte, DataByte data1 = 0, DataByte data2 = 0);
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inline void receive(uint8_t *buffer, uint8_t bufferSize);
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void onConnected(void(*fptr)())
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{
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_connectedCallback = fptr;
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}
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void onDisconnected(void(*fptr)())
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{
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_disconnectedCallback = fptr;
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}
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};
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class MyClientCallbacks: public BLEClientCallbacks {
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public:
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MyClientCallbacks(BleMidiInterfaceClient* BleMidiInterfaceClient) {
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_BleMidiInterfaceClient = BleMidiInterfaceClient;
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}
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protected:
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BleMidiInterfaceClient* _BleMidiInterfaceClient;
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void onConnect(BLEClient* client)
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{
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if (_BleMidiInterfaceClient->_connectedCallback)
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{
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_BleMidiInterfaceClient->_connectedCallback();
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}
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_BleMidiInterfaceClient->_connected = true;
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};
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void onDisconnect(BLEClient* client)
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{
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if (_BleMidiInterfaceClient->_disconnectedCallback)
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{
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_BleMidiInterfaceClient->_disconnectedCallback();
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}
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_BleMidiInterfaceClient->_doConnect = false;
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_BleMidiInterfaceClient->pRemoteService = nullptr;
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_BleMidiInterfaceClient->pRemoteCharacteristic = nullptr;
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doScan = true;
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pBLEScan->start(10, scanCompleteCB);
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}
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};
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class MyAdvertisedDeviceCallbacks: public BLEAdvertisedDeviceCallbacks {
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/**
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* Called for each advertising BLE server.
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*/
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public:
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MyAdvertisedDeviceCallbacks(BleMidiInterfaceClient* BleMidiInterfaceClient) : BLEAdvertisedDeviceCallbacks()
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{
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_BleMidiInterfaceClient = BleMidiInterfaceClient;
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}
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void onResult(BLEAdvertisedDevice advertisedDevice) {
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if (strstr(advertisedDevice.toString().c_str(), _BleMidiInterfaceClient->_deviceName) == NULL)
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{
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// Check that the device matches our host name
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return;
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}
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// We have found a device, let us now see if it contains the service we are looking for.
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if (advertisedDevice.haveServiceUUID() && advertisedDevice.isAdvertisingService(BLEUUID(SERVICE_UUID)))
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{
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BLEDevice::getScan()->stop();
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_BleMidiInterfaceClient->_advertising = new BLEAdvertisedDevice(advertisedDevice);
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_BleMidiInterfaceClient->_doConnect = true;
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doScan = false;
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} // Found our server
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} // onResult
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protected:
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BleMidiInterfaceClient* _BleMidiInterfaceClient;
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}; // MyAdvertisedDeviceCallbacks
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bool BleMidiInterfaceClient::begin(const char* deviceName)
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{
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BLEDevice::init(deviceName);
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strncpy(_deviceName, deviceName, 32);
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pClient = BLEDevice::createClient();
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pClient->setClientCallbacks(new MyClientCallbacks(this));
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// Retrieve a Scanner and set the callback we want to use to be informed when we
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// have detected a new device. Specify that we want active scanning and start the
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// scan to run for 5 seconds.
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pBLEScan = BLEDevice::getScan();
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pBLEScan->setAdvertisedDeviceCallbacks(new MyAdvertisedDeviceCallbacks(this));
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pBLEScan->setInterval(1349);
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pBLEScan->setWindow(449);
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pBLEScan->setActiveScan(true);
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doScan = true;
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pBLEScan->start(10, scanCompleteCB);
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return true;
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}
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void BleMidiInterfaceClient::sendMIDI(StatusByte status, DataByte data1, DataByte data2)
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{
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MidiType type = getTypeFromStatusByte(status);
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Channel channel = getChannelFromStatusByte(status);
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switch (type) {
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case NoteOff:
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if (_noteOffCallback) _noteOffCallback(channel, data1, data2);
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break;
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case NoteOn:
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if (_noteOnCallback) _noteOnCallback(channel, data1, data2);
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break;
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case AfterTouchPoly:
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if (_afterTouchPolyCallback) _afterTouchPolyCallback(channel, data1, data2);
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break;
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case ControlChange:
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if (_controlChangeCallback) _controlChangeCallback(channel, data1, data2);
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break;
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case ProgramChange:
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if (_programChangeCallback) _programChangeCallback(channel, data1);
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break;
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case AfterTouchChannel:
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if (_afterTouchChannelCallback) _afterTouchChannelCallback(channel, data1);
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break;
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case PitchBend:
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if (_pitchBendCallback) {
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int value = (int) ((data1 & 0x7f) | ((data2 & 0x7f) << 7)) + MIDI_PITCHBEND_MIN;
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_pitchBendCallback(channel, value);
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}
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break;
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case SystemExclusive:
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break;
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case TimeCodeQuarterFrame:
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if (_timeCodeQuarterFrameCallback) _timeCodeQuarterFrameCallback(data1);
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break;
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case SongPosition:
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if (_songPositionCallback) {
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unsigned short value = unsigned((data1 & 0x7f) | ((data2 & 0x7f) << 7));
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_songPositionCallback(value);
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}
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break;
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case SongSelect:
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if (_songSelectCallback) _songSelectCallback(data1);
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break;
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case TuneRequest:
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if (_tuneRequestCallback) _tuneRequestCallback();
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break;
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case Clock:
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if (_clockCallback) _clockCallback();
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break;
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case Tick:
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break;
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case Start:
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if (_startCallback) _startCallback();
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break;
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case Continue:
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if (_continueCallback) _continueCallback();
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break;
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case Stop:
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if (_stopCallback) _stopCallback();
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break;
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case ActiveSensing:
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if (_activeSensingCallback) _activeSensingCallback();
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break;
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case SystemReset:
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if (_resetCallback) _resetCallback();
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break;
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}
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}
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void BleMidiInterfaceClient::receive(uint8_t *buffer, uint8_t bufferSize)
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{
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/*
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The general form of a MIDI message follows:
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n-byte MIDI Message
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Byte 0 MIDI message Status byte, Bit 7 is Set to 1.
|
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Bytes 1 to n-1 MIDI message Data bytes, if n > 1. Bit 7 is Set to 0
|
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There are two types of MIDI messages that can appear in a single packet: full MIDI messages and
|
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Running Status MIDI messages. Each is encoded differently.
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A full MIDI message is simply the MIDI message with the Status byte included.
|
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A Running Status MIDI message is a MIDI message with the Status byte omitted. Running Status
|
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MIDI messages may only be placed in the data stream if the following criteria are met:
|
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1. The original MIDI message is 2 bytes or greater and is not a System Common or System
|
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Real-Time message.
|
||||
2. The omitted Status byte matches the most recently preceding full MIDI message’s Status
|
||||
byte within the same BLE packet.
|
||||
In addition, the following rules apply with respect to Running Status:
|
||||
1. A Running Status MIDI message is allowed within the packet after at least one full MIDI
|
||||
message.
|
||||
2. Every MIDI Status byte must be preceded by a timestamp byte. Running Status MIDI
|
||||
messages may be preceded by a timestamp byte. If a Running Status MIDI message is not
|
||||
preceded by a timestamp byte, the timestamp byte of the most recently preceding message
|
||||
in the same packet is used.
|
||||
3. System Common and System Real-Time messages do not cancel Running Status if
|
||||
interspersed between Running Status MIDI messages. However, a timestamp byte must
|
||||
precede the Running Status MIDI message that follows.
|
||||
4. The end of a BLE packet does cancel Running Status.
|
||||
In the MIDI 1.0 protocol, System Real-Time messages can be sent at any time and may be
|
||||
inserted anywhere in a MIDI data stream, including between Status and Data bytes of any other
|
||||
MIDI messages. In the MIDI BLE protocol, the System Real-Time messages must be deinterleaved
|
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from other messages – except for System Exclusive messages.
|
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*/
|
||||
|
||||
//Pointers used to search through payload.
|
||||
uint8_t lPtr = 0;
|
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uint8_t rPtr = 0;
|
||||
|
||||
//lastStatus used to capture runningStatus
|
||||
uint8_t lastStatus;
|
||||
|
||||
//Decode first packet -- SHALL be "Full MIDI message"
|
||||
lPtr = 2; //Start at first MIDI status -- SHALL be "MIDI status"
|
||||
|
||||
//While statement contains incrementing pointers and breaks when buffer size exceeded.
|
||||
while(1){
|
||||
lastStatus = buffer[lPtr];
|
||||
if( (buffer[lPtr] < 0x80) ){
|
||||
//Status message not present, bail
|
||||
return;
|
||||
}
|
||||
//Point to next non-data byte
|
||||
rPtr = lPtr;
|
||||
while( (buffer[rPtr + 1] < 0x80)&&(rPtr < (bufferSize - 1)) ){
|
||||
rPtr++;
|
||||
}
|
||||
//look at l and r pointers and decode by size.
|
||||
if( rPtr - lPtr < 1 ){
|
||||
//Time code or system
|
||||
sendMIDI(lastStatus);
|
||||
} else if( rPtr - lPtr < 2 ) {
|
||||
sendMIDI(lastStatus, buffer[lPtr + 1]);
|
||||
} else if( rPtr - lPtr < 3 ) {
|
||||
sendMIDI(lastStatus, buffer[lPtr + 1], buffer[lPtr + 2]);
|
||||
} else {
|
||||
//Too much data
|
||||
//If not System Common or System Real-Time, send it as running status
|
||||
switch( buffer[lPtr] & 0xF0 )
|
||||
{
|
||||
case NoteOff:
|
||||
case NoteOn:
|
||||
case AfterTouchPoly:
|
||||
case ControlChange:
|
||||
case PitchBend:
|
||||
for(int i = lPtr; i < rPtr; i = i + 2)
|
||||
sendMIDI(lastStatus, buffer[i + 1], buffer[i + 2]);
|
||||
break;
|
||||
case ProgramChange:
|
||||
case AfterTouchChannel:
|
||||
for(int i = lPtr; i < rPtr; i = i + 1)
|
||||
sendMIDI(lastStatus, buffer[i + 1]);
|
||||
break;
|
||||
default:
|
||||
break;
|
||||
}
|
||||
}
|
||||
//Point to next status
|
||||
lPtr = rPtr + 2;
|
||||
if(lPtr >= bufferSize){
|
||||
//end of packet
|
||||
return;
|
||||
}
|
||||
}
|
||||
|
||||
}
|
||||
|
||||
END_BLEMIDI_NAMESPACE
|
||||
|
|
@ -12,4 +12,5 @@
|
|||
|
||||
#if defined(ESP32)
|
||||
#include "Ble_esp32.h"
|
||||
#include "BleMidiClient_esp32.h"
|
||||
#endif
|
||||
|
|
|
|||
|
|
@ -16,6 +16,11 @@ BEGIN_BLEMIDI_NAMESPACE
|
|||
#define BLEMIDI_CREATE_INSTANCE(Name) \
|
||||
BLEMIDI_NAMESPACE::BleMidiInterface Name;
|
||||
|
||||
/*! \brief Create an instance of the library
|
||||
*/
|
||||
#define BLEMIDI_CREATE_CLIENT_INSTANCE(Name) \
|
||||
BLEMIDI_NAMESPACE::BleMidiInterfaceClient Name;
|
||||
|
||||
|
||||
/*! \brief
|
||||
*/
|
||||
|
|
|
|||
Loading…
Reference in New Issue