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| /* Arduino analog to BLE MIDI | |
| Ubi de Feo @ Bar Arduino | |
| https://www.youtube.com/watch?v=0zNmt_IKwRg | |
| supported boards: | |
| - Arduino MKR WiFi 1010 | |
| - Arduino Nano 33 IoT | |
| - Arduino Nano 33 BLE | |
| - Arduino Nano 33 BLE Sense | |
| - Arduino UNO WiFI Rev. 2 | |
| **** Sketch for USB MIDI version (Nano 33 BLE not supported) **** | |
| **** can be found here https://gist.github.com/ubidefeo/6098d95332b6529f1b0599bfd443ebae **** | |
| **** Thank you Larry Bank for pointing out the lack of a BLE version **** | |
| BLE init code courtesy of T. Igoe | |
| https://tigoe.github.io/SoundExamples/midi-ble.html | |
| */ | |
| #include <ArduinoBLE.h> | |
| byte midiData[] = {0x80, 0x80, 0x00, 0x00, 0x00}; | |
| const byte emptyMIDIMessage[] = {0x80, 0x80, 0x00, 0x00, 0x00}; | |
| // set up the MIDI service and MIDI message characteristic: | |
| BLEService midiService("03B80E5A-EDE8-4B33-A751-6CE34EC4C700"); | |
| BLECharacteristic midiCharacteristic("7772E5DB-3868-4112-A1A9-F2669D106BF3", | |
| BLEWrite | BLEWriteWithoutResponse | | |
| BLENotify | BLERead, | |
| sizeof(midiData)); | |
| bool isMIDIOn = false; | |
| void controlChange(byte channel, byte control, byte value) { | |
| midiData[2] = 0xB0 | channel; | |
| midiData[3] = control; | |
| midiData[4] = value; | |
| midiCharacteristic.setValue(midiData, sizeof(midiData)); | |
| } | |
| const int SAMPLES_COUNT = 20; | |
| // FIFO | |
| int samplesBuffer[SAMPLES_COUNT] = {0}; | |
| int sampleIndex = 0; | |
| const int knobInputPin = A1; | |
| const int changeThreshold = 20; | |
| int lastSensorValue; | |
| int lastMappedValue; | |
| unsigned long samplesSum = 0; | |
| void setup() { | |
| Serial.begin(57600); | |
| delay(5000); | |
| // Initialize BLE: | |
| if (!BLE.begin()) { | |
| Serial.println("starting BLE failed!"); | |
| while (true) | |
| ; | |
| } | |
| // set local name and advertised service for BLE: | |
| BLE.setLocalName("ARDUINO_MIDI_BLE"); | |
| BLE.setAdvertisedService(midiService); | |
| // add the characteristic and service: | |
| midiService.addCharacteristic(midiCharacteristic); | |
| BLE.addService(midiService); | |
| // start advertising | |
| BLE.advertise(); | |
| Serial.println("SETUP"); | |
| } | |
| void loop() { | |
| int knobReadOut = filterAnalogValue(knobInputPin); | |
| int mappedValue = map(knobReadOut, 0, 1023, 0, 127); | |
| BLEDevice central = BLE.central(); | |
| // When a central is connected to the peripheral we initially send | |
| // an empty MIDI command in order to let certain platforms acknowledge the MIDI device | |
| // Once that is done we set isMIDIOn to true and do not send the empty message until | |
| // a reconnection happens upon disconnection (isMIDIOn needs to be false) | |
| if (central && !isMIDIOn) { | |
| midiCharacteristic.setValue(emptyMIDIMessage, sizeof(emptyMIDIMessage)); | |
| isMIDIOn = true; | |
| }else{ | |
| isMIDIOn = false; | |
| } | |
| if(isMIDIOn){ | |
| if (lastMappedValue != mappedValue) { | |
| // Serial.println("************ CHANGE ***************"); | |
| // Serial.print(">>> "); | |
| // Serial.print(mappedValue); | |
| // Serial.println(" <<<"); | |
| controlChange(0, 4, mappedValue); | |
| } | |
| lastMappedValue = mappedValue; | |
| } | |
| //delay(100); | |
| } | |
| int filterAnalogValue(int _inputPin) { | |
| samplesSum = 0; | |
| int analogValue = analogRead(_inputPin); | |
| // int valueDelta = abs(analogValue - lastSensorValue); | |
| // Serial.print(analogValue); | |
| // Serial.print(" - "); | |
| // Serial.println(lastSensorValue); | |
| // if(valueDelta < changeThreshold){ | |
| // analogValue = lastSensorValue; | |
| // } | |
| if (sampleIndex < SAMPLES_COUNT) { | |
| samplesBuffer[sampleIndex] = analogValue; | |
| sampleIndex++; | |
| } else { | |
| for (int samplePosition = 0; samplePosition < sampleIndex - 1; | |
| samplePosition++) { | |
| 0; | |
| samplesBuffer[samplePosition] = samplesBuffer[samplePosition + 1]; | |
| } | |
| samplesBuffer[SAMPLES_COUNT - 1] = analogValue; | |
| } | |
| for (int samplePosition = 0; samplePosition < sampleIndex; samplePosition++) { | |
| 0; | |
| samplesSum += samplesBuffer[samplePosition]; | |
| } | |
| // lastSensorValue = analogValue; | |
| if (samplesSum == 0) | |
| return 0; | |
| unsigned int filteredValue = samplesSum / sampleIndex; | |
| return filteredValue; | |
| } |
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