Added secure web example

examples/secure_dfu_node.js

@@ -0,0 +1,98 @@
+var fs = require('fs');
+var bluetooth = require("bleat").webbluetooth;
+var crc = require("crc-32");
+var progress = require('progress');
+var secureDfu = require("../index").secure;
+var bluetoothDevices = [];
+
+var dat = fs.readFileSync("test_images_update_nrf52832/dfu_test_app_hrm_s132/nrf52832_xxaa.dat");
+var bin = fs.readFileSync("test_images_update_nrf52832/dfu_test_app_hrm_s132/nrf52832_xxaa.bin");
+
+function logError(error) {
+    console.log(error);
+    process.exit();
+}
+
+process.stdin.setEncoding('utf8');
+process.stdin.on('readable', () => {
+    var input = process.stdin.read();
+    if (input === '\u0003') {
+        process.exit();
+    } else {
+        var index = parseInt(input);
+        if (index && index <= bluetoothDevices.length) {
+            process.stdin.setRawMode(false);
+            selectDevice(index - 1);
+        }
+    }
+});
+
+function toArrayBuffer(buffer) {
+    var ab = new ArrayBuffer(buffer.length);
+    var view = new Uint8Array(ab);
+    for (var i = 0; i < buffer.length; ++i) {
+        view[i] = buffer[i];
+    }
+    return ab;
+}
+
+function selectDevice(index) {
+    var bar = null;
+    var device = bluetoothDevices[index];
+    var dfu = new secureDfu(crc.buf);
+    dfu.addEventListener("progress", event => {
+        if (bar) bar.update(event.currentBytes / event.totalBytes);
+    });
+
+    console.log();
+
+    dfu.connect(device)
+    .then(() => {
+        process.stdout.write("Transferring init packet...");
+        return dfu.transferInit(toArrayBuffer(dat));
+    })
+    .then(data => {
+        console.log("Done");
+        var data = toArrayBuffer(bin);
+        bar = new progress('Transferring firmware [:bar] :percent :etas', {
+            complete: '=',
+            incomplete: ' ',
+            width: 20,
+            total: data.byteLength
+        });
+        return dfu.transferFirmware(data);
+    })
+    .then(() => {
+        console.log("\nComplete!");
+        process.exit();
+    })
+    .catch(logError);
+}
+
+function handleDeviceFound(bluetoothDevice) {
+    var discovered = bluetoothDevices.some(device => {
+        return (device.id === bluetoothDevice.id);
+    });
+    if (discovered) return;
+
+    if (bluetoothDevices.length === 0) {
+        process.stdin.setRawMode(true);
+        console.log("Select a device to update:");
+    }
+
+    bluetoothDevices.push(bluetoothDevice);
+    console.log(bluetoothDevices.length + ": " + bluetoothDevice.name);
+}
+
+console.log("Scanning for DFU devices...");
+bluetooth.requestDevice({
+    filters: [{ services: [0xFE59] }],
+	deviceFound: handleDeviceFound
+})
+.then(() => {
+    if (bluetoothDevices.length === 0) {
+        console.log("no devices found");
+        process.exit();
+    }
+})
+.catch(logError);