Use the CRC we generate for the image in the init packet.

dist/dfu.js

@@ -162,10 +162,11 @@
         return view;
     }
 
-    function provision(device, arrayBuffer, imageType) {
+    function provision(device, arrayBuffer, imageType, crc) {
         return new Promise(function(resolve, reject) {
             var versionChar = null;
             imageType = imageType || ImageType.Application;
+            initPacket.crc = crc;
 
             connect(device)
             .then(function(chars) {

example_node.js

@@ -1,5 +1,6 @@
 var dfu = require('./index').dfu;
 var hex2bin = require('./index').hex2bin;
+var crc16 = require('./index').crc16;
 var fs = require('fs');
 
 var log = console.log;
@@ -40,8 +41,9 @@ dfu.findDevice({ services: [0x180D] })
     var hex = file.toString();
     var buffer = hex2bin(hex);
     log("file length: " + buffer.byteLength);
+    var crc = crc16(buffer);
 
-    return dfu.provision(device, buffer);
+    return dfu.provision(device, buffer, 4, crc);
 })
 .then(() => process.exit())
 .catch(error => {

example_web.html

@@ -27,6 +27,7 @@
 
     <script src="dist/dfu.js"></script>
     <script src="dist/hex2bin.js"></script>
+    <script src="dist/crc16.js"></script>
 
     <script>
         var resultsEl = document.getElementById("results");
@@ -68,8 +69,9 @@
                 .then(hex => {
                     var buffer = hex2bin(hex);
                     log("downloaded length: " + buffer.byteLength);
+                    var crc = crc16(buffer);
 
-                    return dfu.provision(device, buffer);
+                    return dfu.provision(device, buffer, 4, crc);
                 })
                 .then(() => {
                     log('dfu complete');

index.js

@@ -2,8 +2,10 @@ require('bleat');
 
 var dfu = require('./dist/dfu');
 var hex2bin = require('./dist/hex2bin');
+var crc16 = require('./dist/crc16');
 
 module.exports = {
     dfu: dfu,
-    hex2bin: hex2bin
+    hex2bin: hex2bin,
+    crc16: crc16
 };