我正在尝试获取一个iOS Cordova应用程序以连接到Arduino Nano 33 BLE。我正在处理下面的Arduino BLE LED示例和Cordova Redbear BLE-Central示例。我的Arduino出现在应用程序中的设备列表中，但是当我尝试连接时，出现以下错误：
尝试在无对象引用上调用虚拟方法'java.util.UUID android.bluetooth.BluetoothGattCharacteristic.getUuid（）'。
有人可以告诉我我做错了什么或如何使它正常工作吗？谢谢。
Arduino草图：
#include <ArduinoBLE.h>
BLEService ledService("19B10000-E8F2-537E-4F6C-D104768A1214"); // BLE LED Service
// BLE LED Switch Characteristic - custom 128-bit UUID, read and writable by central
BLEByteCharacteristic switchCharacteristic("19B10001-E8F2-537E-4F6C-D104768A1214", BLERead | BLEWrite);
const int ledPin = LED_BUILTIN; // pin to use for the LED
void setup() {
Serial.begin(9600);
while (!Serial);
// set LED pin to output mode
pinMode(ledPin, OUTPUT);
// begin initialization
if (!BLE.begin()) {
Serial.println("starting BLE failed!");
while (1);
}
// set advertised local name and service UUID:
BLE.setLocalName("LED");
BLE.setAdvertisedService(ledService);
// add the characteristic to the service
ledService.addCharacteristic(switchCharacteristic);
// add service
BLE.addService(ledService);
// set the initial value for the characeristic:
switchCharacteristic.writeValue(0);
// start advertising
BLE.advertise();
Serial.println("BLE LED Peripheral");
}
void loop() {
// listen for BLE peripherals to connect:
BLEDevice central = BLE.central();
// if a central is connected to peripheral:
if (central) {
Serial.print("Connected to central: ");
// print the central's MAC address:
Serial.println(central.address());
// while the central is still connected to peripheral:
while (central.connected()) {
// if the remote device wrote to the characteristic,
// use the value to control the LED:
if (switchCharacteristic.written()) {
if (switchCharacteristic.value()) { // any value other than 0
Serial.println("LED on");
digitalWrite(ledPin, HIGH); // will turn the LED on
} else { // a 0 value
Serial.println(F("LED off"));
digitalWrite(ledPin, LOW); // will turn the LED off
}
}
}
// when the central disconnects, print it out:
Serial.print(F("Disconnected from central: "));
Serial.println(central.address());
}
}
科尔多瓦index.js：
'use strict';
// ASCII only
function bytesToString(buffer) {
return String.fromCharCode.apply(null, new Uint8Array(buffer));
}
// ASCII only
function stringToBytes(string) {
var array = new Uint8Array(string.length);
for (var i = 0, l = string.length; i < l; i++) {
array[i] = string.charCodeAt(i);
}
return array.buffer;
}
// this is RedBear Lab's UART service
var redbear = {
serviceUUID: "19B10000-E8F2-537E-4F6C-D104768A1214",
txCharacteristic: "19B10001-E8F2-537E-4F6C-D104768A1214", // transmit is from the phone's perspective
rxCharacteristic: "19B10002-E8F2-537E-4F6C-D104768A1214" // receive is from the phone's perspective
};
var app = {
initialize: function() {
this.bindEvents();
detailPage.hidden = true;
},
bindEvents: function() {
document.addEventListener('deviceready', this.onDeviceReady, false);
refreshButton.addEventListener('touchstart', this.refreshDeviceList, false);
sendButton.addEventListener('click', this.sendData, false);
disconnectButton.addEventListener('touchstart', this.disconnect, false);
deviceList.addEventListener('touchstart', this.connect, false); // assume not scrolling
},
onDeviceReady: function() {
app.refreshDeviceList();
},
refreshDeviceList: function() {
deviceList.innerHTML = ''; // empties the list
if (cordova.platformId === 'android') { // Android filtering is broken
ble.scan([], 5, app.onDiscoverDevice, app.onError);
} else {
ble.scan([redbear.serviceUUID], 5, app.onDiscoverDevice, app.onError);
}
},
onDiscoverDevice: function(device) {
var listItem = document.createElement('li'),
html = '<b>' + device.name + '</b><br/>' +
'RSSI: ' + device.rssi + ' | ' +
device.id;
listItem.dataset.deviceId = device.id;
listItem.innerHTML = html;
deviceList.appendChild(listItem);
},
connect: function(e) {
var deviceId = e.target.dataset.deviceId,
onConnect = function() {
// subscribe for incoming data
ble.startNotification(deviceId, redbear.serviceUUID, redbear.rxCharacteristic, app.onData, app.onError);
sendButton.dataset.deviceId = deviceId;
disconnectButton.dataset.deviceId = deviceId;
app.showDetailPage();
};
ble.connect(deviceId, onConnect, app.onError);
},
onData: function(data) { // data received from Arduino
console.log(data);
resultDiv.innerHTML = resultDiv.innerHTML + "Received: " + bytesToString(data) + "<br/>";
resultDiv.scrollTop = resultDiv.scrollHeight;
},
sendData: function(event) { // send data to Arduino
var success = function() {
console.log("success");
resultDiv.innerHTML = resultDiv.innerHTML + "Sent: " + messageInput.value + "<br/>";
resultDiv.scrollTop = resultDiv.scrollHeight;
};
var failure = function() {
alert("Failed writing data to the redbear hardware");
};
var data = stringToBytes(messageInput.value);
var deviceId = event.target.dataset.deviceId;
ble.writeWithoutResponse(deviceId, redbear.serviceUUID, redbear.txCharacteristic, data, success, failure);
},
disconnect: function(event) {
var deviceId = event.target.dataset.deviceId;
ble.disconnect(deviceId, app.showMainPage, app.onError);
},
showMainPage: function() {
mainPage.hidden = false;
detailPage.hidden = true;
},
showDetailPage: function() {
mainPage.hidden = true;
detailPage.hidden = false;
},
onError: function(reason) {
alert("ERROR: " + reason); // real apps should use notification.alert
}
};