<?xml version="1.0" encoding="UTF-8" ?>
<?xml-stylesheet type="text/xsl" href="https://devzone.nordicsemi.com/cfs-file/__key/system/syndication/rss.xsl" media="screen"?><rss version="2.0" xmlns:dc="http://purl.org/dc/elements/1.1/" xmlns:slash="http://purl.org/rss/1.0/modules/slash/" xmlns:wfw="http://wellformedweb.org/CommentAPI/" xmlns:atom="http://www.w3.org/2005/Atom"><channel><title>UNABLE TO GENERATE PRIVATE KEY</title><link>https://devzone.nordicsemi.com/f/nordic-q-a/43955/unable-to-generate-private-key</link><description>Hi, 
 I am following a tutorial in order to learn the procedure for DFU OTA . I installed the nrfutil but still unable to generate the private key. 
 I have tried several commands like : 
 nrfutil.exe keys generate private.key nrfutil.exe keys generate</description><dc:language>en-US</dc:language><generator>Telligent Community 13</generator><lastBuildDate>Wed, 03 Apr 2019 05:52:33 GMT</lastBuildDate><atom:link rel="self" type="application/rss+xml" href="https://devzone.nordicsemi.com/f/nordic-q-a/43955/unable-to-generate-private-key" /><item><title>RE: UNABLE TO GENERATE PRIVATE KEY</title><link>https://devzone.nordicsemi.com/thread/179874?ContentTypeID=1</link><pubDate>Wed, 03 Apr 2019 05:52:33 GMT</pubDate><guid isPermaLink="false">137ad170-7792-4731-bb38-c0d22fbe4515:6a466f68-05b6-4b8e-944a-b23d70bb4382</guid><dc:creator>AndreasF</dc:creator><description>&lt;p&gt;Hi&lt;/p&gt;
&lt;p&gt;Great, I will close this ticket then.&lt;/p&gt;
&lt;p&gt;Best regards,&lt;/p&gt;
&lt;p&gt;Andreas&lt;/p&gt;&lt;div style="clear:both;"&gt;&lt;/div&gt;</description></item><item><title>RE: UNABLE TO GENERATE PRIVATE KEY</title><link>https://devzone.nordicsemi.com/thread/179861?ContentTypeID=1</link><pubDate>Wed, 03 Apr 2019 00:38:20 GMT</pubDate><guid isPermaLink="false">137ad170-7792-4731-bb38-c0d22fbe4515:06665e75-edca-463b-b615-bcb68feed1c2</guid><dc:creator>inghowe83</dc:creator><description>&lt;p&gt;Hi Andrea,&lt;/p&gt;
&lt;p&gt;I fixed the problem.&lt;/p&gt;
&lt;p&gt;I assigned a wrong softdevice code when prepare the dfu package! I should use 0xAE.&lt;/p&gt;&lt;div style="clear:both;"&gt;&lt;/div&gt;</description></item><item><title>RE: UNABLE TO GENERATE PRIVATE KEY</title><link>https://devzone.nordicsemi.com/thread/179738?ContentTypeID=1</link><pubDate>Tue, 02 Apr 2019 11:47:36 GMT</pubDate><guid isPermaLink="false">137ad170-7792-4731-bb38-c0d22fbe4515:1a9c3978-6b50-407c-aaa4-f35633a000e7</guid><dc:creator>AndreasF</dc:creator><description>&lt;p&gt;Hi.&lt;/p&gt;
&lt;p&gt;Could you create a new ticket for this issue?&lt;/p&gt;
&lt;p&gt;Since this question is not the same as the one asked in the start of this ticket, and it will be hard for other community members to find it when they are searching.&lt;/p&gt;
&lt;p&gt;Best regards,&lt;/p&gt;
&lt;p&gt;Andreas&lt;/p&gt;&lt;div style="clear:both;"&gt;&lt;/div&gt;</description></item><item><title>RE: UNABLE TO GENERATE PRIVATE KEY</title><link>https://devzone.nordicsemi.com/thread/179621?ContentTypeID=1</link><pubDate>Tue, 02 Apr 2019 00:46:10 GMT</pubDate><guid isPermaLink="false">137ad170-7792-4731-bb38-c0d22fbe4515:941ac4f8-9158-49c3-a7e1-c345116fa395</guid><dc:creator>inghowe83</dc:creator><description>&lt;p&gt;Hi Andreas,&lt;/p&gt;
&lt;p&gt;Thanks for providing the step. I verify your step and notice I wasn&amp;#39;t able to program the device.&lt;/p&gt;
&lt;p&gt;1) Connect to DFUTARG.&lt;/p&gt;
&lt;p&gt;2) Select file type -&amp;gt; Distribution packet (Zip)&lt;/p&gt;
&lt;p&gt;3) Select app_dfu_package.zip&lt;/p&gt;
&lt;p&gt;4) The app show Disconnecting without the dfu programming progress bar.&lt;/p&gt;
&lt;p&gt;&lt;img src="https://devzone.nordicsemi.com/resized-image/__size/640x480/__key/communityserver-discussions-components-files/4/pastedimage1554165947721v1.png" alt=" " /&gt;&lt;/p&gt;&lt;div style="clear:both;"&gt;&lt;/div&gt;</description></item><item><title>RE: UNABLE TO GENERATE PRIVATE KEY</title><link>https://devzone.nordicsemi.com/thread/175839?ContentTypeID=1</link><pubDate>Wed, 13 Mar 2019 08:36:39 GMT</pubDate><guid isPermaLink="false">137ad170-7792-4731-bb38-c0d22fbe4515:264f5ab6-954b-490b-b57d-27acfe5f6c88</guid><dc:creator>AndreasF</dc:creator><description>&lt;p&gt;Hi.&lt;/p&gt;
&lt;p&gt;If you want to enter DFU mode there are other ways to do that without the use of a button. For example:&lt;/p&gt;
&lt;p&gt;&lt;/p&gt;
&lt;ul&gt;
&lt;li&gt;Pin reset (&lt;a href="https://www.nordicsemi.com/DocLib/Content/SDK_Doc/nRF5_SDK/v15-3-0/group__nrf__bootloader__config#gaa89bea64482f2c4d83919922e5e84bc3"&gt;NRF_BL_DFU_ENTER_METHOD_PINRESET&lt;/a&gt;),&lt;/li&gt;
&lt;li&gt;Special value in GPREGRET register (&lt;a href="https://www.nordicsemi.com/DocLib/Content/SDK_Doc/nRF5_SDK/v15-3-0/group__nrf__bootloader__config#ga4e1297da5d25948277b4323a6fb87659"&gt;NRF_BL_DFU_ENTER_METHOD_GPREGRET&lt;/a&gt;),&lt;/li&gt;
&lt;li&gt;Request from the application written to the settings page (&lt;a href="https://www.nordicsemi.com/DocLib/Content/SDK_Doc/nRF5_SDK/v15-3-0/group__nrf__bootloader__config#gab540083b75cd50e020bbd166198476c4"&gt;NRF_BL_DFU_ENTER_METHOD_BUTTONLESS&lt;/a&gt;).&lt;/li&gt;
&lt;/ul&gt;
&lt;p&gt;All these are described in the &lt;a href="https://www.nordicsemi.com/DocLib/Content/SDK_Doc/nRF5_SDK/v15-3-0/lib_bootloader?307#lib_bootloader_dfu_mode"&gt;DFU mode&lt;/a&gt; section in DocLib.&lt;/p&gt;
&lt;p&gt;&lt;/p&gt;
&lt;p&gt;If you want to start in DFU mode just enter DFU mode on start up and set for example &lt;a href="https://www.nordicsemi.com/DocLib/Content/SDK_Doc/nRF5_SDK/v15-3-0/group__nrf__bootloader__config#gac4b458d2cbbdc42f27f223871360b546"&gt;NRF_BL_DFU_INACTIVITY_TIMEOUT_MS&lt;/a&gt; to 30 seconds.&lt;/p&gt;
&lt;p&gt;You can follow the &lt;a href="https://www.nordicsemi.com/DocLib/Content/SDK_Doc/nRF5_SDK/v15-3-0/service_dfu"&gt;implementation guide &lt;/a&gt;of the Buttonless Secure DFU service, this will show you how to enter DFU mode from the Application.&lt;/p&gt;
&lt;p&gt;Best regards,&lt;/p&gt;
&lt;p&gt;Andreas&lt;/p&gt;&lt;div style="clear:both;"&gt;&lt;/div&gt;</description></item><item><title>RE: UNABLE TO GENERATE PRIVATE KEY</title><link>https://devzone.nordicsemi.com/thread/175781?ContentTypeID=1</link><pubDate>Tue, 12 Mar 2019 19:38:34 GMT</pubDate><guid isPermaLink="false">137ad170-7792-4731-bb38-c0d22fbe4515:8ded87b8-4671-4c7e-bdbb-8cae5ca971e8</guid><dc:creator>arshdeep</dc:creator><description>&lt;p&gt;Hi Andreas,&lt;/p&gt;
&lt;p&gt;&lt;/p&gt;
&lt;p&gt;I have been told that i will be answered on Thursday/Friday. We are in a rush now. Will you able to provide some insights on this ?&lt;/p&gt;
&lt;p&gt;&lt;/p&gt;
&lt;p&gt;Thanks,&amp;nbsp;&lt;/p&gt;&lt;div style="clear:both;"&gt;&lt;/div&gt;</description></item><item><title>RE: UNABLE TO GENERATE PRIVATE KEY</title><link>https://devzone.nordicsemi.com/thread/175586?ContentTypeID=1</link><pubDate>Tue, 12 Mar 2019 09:54:39 GMT</pubDate><guid isPermaLink="false">137ad170-7792-4731-bb38-c0d22fbe4515:d4366349-7f45-47ef-af25-5be8ca1b8b8e</guid><dc:creator>AndreasF</dc:creator><description>&lt;p&gt;Hi.&lt;/p&gt;
&lt;p&gt;I see that you created a new ticket for this question, so it will be answered there by one of my colleagues.&lt;/p&gt;
&lt;p&gt;Best regards,&lt;/p&gt;
&lt;p&gt;Andreas&lt;/p&gt;&lt;div style="clear:both;"&gt;&lt;/div&gt;</description></item><item><title>RE: UNABLE TO GENERATE PRIVATE KEY</title><link>https://devzone.nordicsemi.com/thread/175492?ContentTypeID=1</link><pubDate>Mon, 11 Mar 2019 22:17:25 GMT</pubDate><guid isPermaLink="false">137ad170-7792-4731-bb38-c0d22fbe4515:1db0010c-c86c-4b2b-92a7-e8607c3a6daa</guid><dc:creator>arshdeep</dc:creator><description>&lt;p&gt;Hi Andreas,&lt;/p&gt;
&lt;p&gt;&lt;/p&gt;
&lt;p&gt;Yes i figured that by reading through the app notes that I will not have to upload the bootloader again. But my big question is how to switch to DFU mode without a button ??Our custom board does not have a dedicated button for this task .&amp;nbsp;&lt;/p&gt;
&lt;p&gt;So we will like our board to always start in a&amp;nbsp; DFU mode, look for new firmware package for initial 30sec and switch back to normal application after that.&amp;nbsp; This will happen every time we power up the board.&amp;nbsp;&lt;/p&gt;
&lt;p&gt;To achieve this, I was reading a lot about DFU_BUTTONLESS example but could not figure out the right procedure to do so.&amp;nbsp;&amp;nbsp;&lt;/p&gt;
&lt;p&gt;Will I have to change the structure of my application or will this logic be implemented inside the bootloader?&amp;nbsp;&lt;/p&gt;
&lt;p&gt;&lt;/p&gt;
&lt;p&gt;Can you please provide some guiding steps to do so and if possible a pseudo code .&lt;/p&gt;
&lt;p&gt;&lt;/p&gt;
&lt;p&gt;Thanks,&lt;/p&gt;
&lt;p&gt;Arshdeep&lt;/p&gt;&lt;div style="clear:both;"&gt;&lt;/div&gt;</description></item><item><title>RE: UNABLE TO GENERATE PRIVATE KEY</title><link>https://devzone.nordicsemi.com/thread/175297?ContentTypeID=1</link><pubDate>Mon, 11 Mar 2019 11:36:33 GMT</pubDate><guid isPermaLink="false">137ad170-7792-4731-bb38-c0d22fbe4515:16ed58ce-d309-4681-bf3d-089f930b72cd</guid><dc:creator>AndreasF</dc:creator><description>&lt;p&gt;Hi.&lt;br /&gt;&lt;br /&gt;Sorry for the late reply, I have been away for a few days.&lt;br /&gt;&lt;br /&gt;It depends on what you want to upgrade.&lt;br /&gt;&lt;br /&gt;The reason for programming the bootloader first in the examples, is that we need a bootloader in order to do the DFU. If your Application already has a bootloader, you don&amp;#39;t need to program another bootloader.&lt;/p&gt;
&lt;p&gt;&lt;br /&gt;The DFU procedure is well documented &lt;a href="https://www.nordicsemi.com/DocLib/Content/SDK_Doc/nRF5_SDK/v15-3-0/lib_bootloader_dfu_process"&gt;here&lt;/a&gt;, could you take a look at that? &lt;/p&gt;
&lt;p&gt;Best regards,&lt;/p&gt;
&lt;p&gt;Andreas&lt;/p&gt;&lt;div style="clear:both;"&gt;&lt;/div&gt;</description></item><item><title>RE: UNABLE TO GENERATE PRIVATE KEY</title><link>https://devzone.nordicsemi.com/thread/174638?ContentTypeID=1</link><pubDate>Wed, 06 Mar 2019 16:48:14 GMT</pubDate><guid isPermaLink="false">137ad170-7792-4731-bb38-c0d22fbe4515:a57ce5ac-5e5c-4395-a704-f52a92cc7705</guid><dc:creator>arshdeep</dc:creator><description>&lt;p&gt;Hi Andreas,&lt;/p&gt;
&lt;p&gt;It did work!!!&amp;nbsp; You were a great help and support . I am glad to be using a Nordic product.&lt;/p&gt;
&lt;p&gt;I only have one last question, which if you will say I can open a separate ticket for:&lt;/p&gt;
&lt;p&gt;What will be the procedure for our customers to be able to upgrade the firmware using OTA DFU? I see that every time we will have to do a DFU, we need to program the bootloader first . How will our customer using the product will do that ?&lt;/p&gt;
&lt;p&gt;Every time we have a new firmware release, will we have to generate a new set of private and public key ?&lt;/p&gt;
&lt;p&gt;&lt;/p&gt;
&lt;p&gt;Thanks again Andreas for all the help.&lt;/p&gt;
&lt;p&gt;&lt;/p&gt;
&lt;p&gt;Regards,&lt;/p&gt;
&lt;p&gt;Arshdeep&lt;/p&gt;&lt;div style="clear:both;"&gt;&lt;/div&gt;</description></item><item><title>RE: UNABLE TO GENERATE PRIVATE KEY</title><link>https://devzone.nordicsemi.com/thread/174523?ContentTypeID=1</link><pubDate>Wed, 06 Mar 2019 11:42:52 GMT</pubDate><guid isPermaLink="false">137ad170-7792-4731-bb38-c0d22fbe4515:05081797-0010-4144-bee1-5cfcc234b302</guid><dc:creator>AndreasF</dc:creator><description>&lt;p&gt;Hi.&lt;/p&gt;
&lt;p&gt;Sorry for the confusion, I will try to make things a bit clearer.&lt;/p&gt;
&lt;p&gt;nrfjprog is a part of the nRF5x Command Line Tools and you can find a user guide &lt;a href="https://www.nordicsemi.com/DocLib/Content/User_Guides/nrf5x_cltools/latest/UG/cltools/nrf5x_command_line_tools_lpage"&gt;here&lt;/a&gt;. The installation is described &lt;a href="https://www.nordicsemi.com/DocLib/Content/User_Guides/nrf5x_cltools/latest/UG/cltools/nrf5x_installation"&gt;here&lt;/a&gt;. And a command reference list is described &lt;a href="https://www.nordicsemi.com/DocLib/Content/User_Guides/nrf5x_cltools/latest/UG/cltools/nrf5x_nrfjprogexe_reference"&gt;here&lt;/a&gt;.&amp;nbsp; When you have installed the Command Line Tools, you can open a &lt;strong&gt;cmd&amp;nbsp;&lt;/strong&gt;window and type &amp;quot;nrfjprog.exe -e&amp;quot;. This will erase available code and UICR flash areas and reset the device, like this:&lt;/p&gt;
&lt;p&gt;&lt;img src="https://devzone.nordicsemi.com/resized-image/__size/320x240/__key/support-attachments/beef5d1b77644c448dabff31668f3a47-03b17c4fe5f249bb94a4b3187c6f7777/pastedimage1551866114875v1.png" alt=" " /&gt;&lt;/p&gt;
&lt;p&gt;&lt;/p&gt;
&lt;p&gt;The bootloader question:&lt;/p&gt;
&lt;p&gt;Can we start from scratch, where you follow this procedure:&lt;/p&gt;
&lt;p&gt;&lt;strong&gt;Step 1.&lt;/strong&gt;&lt;/p&gt;
&lt;p&gt;Generate a private key by running this command in &lt;strong&gt;cmd&lt;/strong&gt; in your SDK 15 folder:&lt;/p&gt;
&lt;p&gt;&lt;strong&gt;nrfutil keys generate priv.pem&lt;/strong&gt;&lt;/p&gt;
&lt;p&gt;&lt;strong&gt;Step 2.&lt;/strong&gt;&lt;/p&gt;
&lt;p&gt;Generate a public key file from that private key by running this command in &lt;strong&gt;cmd&lt;/strong&gt; in your SDK 15 folder:&lt;/p&gt;
&lt;p&gt;nrfutil keys display --key pk --format code priv.pem --out_file dfu_public_key.c&lt;/p&gt;
&lt;p&gt;You should now have a file named &lt;strong&gt;dfu_public_key.c&lt;/strong&gt; in your SDK 15 folder.&lt;/p&gt;
&lt;p&gt;&lt;strong&gt;Step 3.&lt;/strong&gt;&lt;/p&gt;
&lt;p&gt;Open the folder &lt;strong&gt;nRF5_SDK_15.0.0_a53641a\examples\dfu&lt;/strong&gt;&lt;/p&gt;
&lt;p&gt;You see that there is a file named &lt;strong&gt;dfu_public_key.c&lt;/strong&gt;, delete this file.&lt;/p&gt;
&lt;p&gt;Take the file you generated in &lt;strong&gt;step 2&lt;/strong&gt; and move it to this folder.&lt;/p&gt;
&lt;p&gt;&lt;strong&gt;Step 4.&lt;/strong&gt;&lt;/p&gt;
&lt;p&gt;Open up the &lt;strong&gt;SES&lt;/strong&gt; project in the folder &lt;strong&gt;nRF5_SDK_15.0.0_a53641a\examples\dfu\secure_bootloader\pca10056_ble\ses&lt;/strong&gt; and build it.&lt;/p&gt;
&lt;p&gt;After you have built it the folders: \Output\Release\Exe will appear in the folder structure. Open these folders and copy the file named &lt;strong&gt;secure_bootloader_ble_s140_pca10056.hex&lt;/strong&gt; to your SDK 15 folder. This is the &lt;strong&gt;.hex &lt;/strong&gt;file for the secure bootloader you have created.&lt;/p&gt;
&lt;p&gt;&lt;strong&gt;Step 5.&lt;/strong&gt;&lt;/p&gt;
&lt;p&gt;Open the folder &lt;strong&gt;nRF5_SDK_15.0.0_a53641a\components\softdevice\s140\hex, &lt;/strong&gt;and copy the &lt;strong&gt;.hex file &lt;/strong&gt;&lt;strong&gt;s140_nrf52_6.0.0_softdevice.hex&lt;/strong&gt; to your SDK 15 folder.&lt;/p&gt;
&lt;p&gt;&lt;strong&gt;Step 6.&lt;/strong&gt;&lt;/p&gt;
&lt;p&gt;Create an application, for example the ble_app_bms example, and copy the &lt;strong&gt;.hex file&lt;/strong&gt; as you did for the bootloader to your SDK 15 folder (you find the &lt;strong&gt;.hex file &lt;/strong&gt;in&lt;strong&gt; nRF5_SDK_15.0.0_a53641a\examples\ble_peripheral\ble_app_bms\pca10056\s140\ses\Output\Release\Exe, named ble_app_bms_pca10056_s140.hex&lt;/strong&gt;)&lt;/p&gt;
&lt;p&gt;&lt;strong&gt;Step 7.&lt;/strong&gt;&lt;/p&gt;
&lt;p&gt;Generate a &lt;a href="https://www.nordicsemi.com/DocLib/Content/User_Guides/nrfutil/latest/UG/nrfutil/nrfutil_settings_generate_display"&gt;bootloader settings&lt;/a&gt; page by running this command in &lt;strong&gt;cmd&lt;/strong&gt; in your SDK 15 folder:&lt;/p&gt;
&lt;p&gt;&lt;strong&gt;nrfutil settings generate --family NRF52840 --application ble_app_bms_pca10056_s140.hex --application-version 3 --bootloader-version 2 --bl-settings-version 1 settings.hex&lt;/strong&gt;&lt;/p&gt;
&lt;p&gt;The output looks like this:&lt;/p&gt;
&lt;p&gt;&lt;img src="https://devzone.nordicsemi.com/resized-image/__size/320x240/__key/support-attachments/beef5d1b77644c448dabff31668f3a47-03b17c4fe5f249bb94a4b3187c6f7777/pastedimage1551867851662v3.png" alt=" " /&gt;&lt;/p&gt;
&lt;p&gt;&lt;strong&gt;Step 8.&lt;/strong&gt;&lt;/p&gt;
&lt;p&gt;&lt;strong&gt;&lt;/strong&gt;Merge the &lt;strong&gt;settings.hex&lt;/strong&gt; and &lt;strong&gt;secure_bootloader_ble_s140_pca10056.hex&lt;/strong&gt; together by running this command in &lt;strong&gt;cmd&lt;/strong&gt; in your SDK 15 folder:&lt;/p&gt;
&lt;p&gt;mergehex.exe --merge settings.hex secure_bootloader_ble_s140_pca10056.hex --output my_bootloader.hex&lt;/p&gt;
&lt;p&gt;The output looks like this:&lt;/p&gt;
&lt;p&gt;&lt;img src="https://devzone.nordicsemi.com/resized-image/__size/320x240/__key/support-attachments/beef5d1b77644c448dabff31668f3a47-03b17c4fe5f249bb94a4b3187c6f7777/pastedimage1551867966220v4.png" alt=" " /&gt;&lt;/p&gt;
&lt;p&gt;&lt;strong&gt;Step 9.&lt;/strong&gt;&lt;/p&gt;
&lt;p&gt;Generate the DFU packet by running this command in &lt;strong&gt;cmd&lt;/strong&gt; in your SDK 15 folder:&lt;/p&gt;
&lt;p&gt;nrfutil pkg generate --hw-version 52 --application-version 3 --application ble_app_bms_pca10056_s140.hex --sd-req 0xA9 --key-file priv.pem app_dfu_package.zip&lt;/p&gt;
&lt;p&gt;The output looks like this:&lt;/p&gt;
&lt;p&gt;&lt;img src="https://devzone.nordicsemi.com/resized-image/__size/320x240/__key/support-attachments/beef5d1b77644c448dabff31668f3a47-03b17c4fe5f249bb94a4b3187c6f7777/pastedimage1551868167893v5.png" alt=" " /&gt;&lt;/p&gt;
&lt;p&gt;&lt;strong&gt;Step 10&lt;/strong&gt;.&lt;/p&gt;
&lt;p&gt;You should now have these files in the SDK 15 folder:&lt;/p&gt;
&lt;p&gt;&lt;img src="https://devzone.nordicsemi.com/resized-image/__size/320x240/__key/support-attachments/beef5d1b77644c448dabff31668f3a47-03b17c4fe5f249bb94a4b3187c6f7777/pastedimage1551868212135v6.png" alt=" " /&gt;&lt;/p&gt;
&lt;p&gt;app_dfu_package.zip&lt;/p&gt;
&lt;p&gt;ble_app_bms_pca10056_s140.hex&lt;/p&gt;
&lt;p&gt;my_bootloader.hex&lt;/p&gt;
&lt;p&gt;priv.pem&lt;/p&gt;
&lt;p&gt;s140_nrf52_6.0.0_softdevice.hex&lt;/p&gt;
&lt;p&gt;secure_bootloader_ble_s140_pca10056.hex&lt;/p&gt;
&lt;p&gt;settings.hex&lt;/p&gt;
&lt;p&gt;&lt;strong&gt;Step 11.&lt;/strong&gt;&lt;/p&gt;
&lt;p&gt;Open the SDK 15 folder in &lt;strong&gt;cmd&lt;/strong&gt;, and write the commands:&lt;/p&gt;
&lt;p&gt;nrfjprog.exe -e&lt;/p&gt;
&lt;p&gt;nrfjprog.exe --program s140_nrf52_6.0.0_softdevice.hex --verify&lt;/p&gt;
&lt;p&gt;nrfjprog.exe --program my_bootloader.hex --verify -r&lt;/p&gt;
&lt;p&gt;The output looks like this:&lt;/p&gt;
&lt;p&gt;&lt;img src="https://devzone.nordicsemi.com/resized-image/__size/320x240/__key/support-attachments/beef5d1b77644c448dabff31668f3a47-03b17c4fe5f249bb94a4b3187c6f7777/pastedimage1551868413604v7.png" alt=" " /&gt;&lt;/p&gt;
&lt;p&gt;You have now programmed the SoftDevice and the Bootloader including the bootloader settings page.&lt;/p&gt;
&lt;p&gt;&lt;strong&gt;Step 12.&lt;/strong&gt;&lt;/p&gt;
&lt;p&gt;Open &lt;strong&gt;nRF Connect&lt;/strong&gt; on your mobile phone and scan:&lt;/p&gt;
&lt;p&gt;&lt;img src="https://devzone.nordicsemi.com/resized-image/__size/320x240/__key/support-attachments/beef5d1b77644c448dabff31668f3a47-03b17c4fe5f249bb94a4b3187c6f7777/pastedimage1551872332747v8.png" alt=" " /&gt;&lt;/p&gt;
&lt;p&gt;When you find &lt;strong&gt;DfuTarg&lt;/strong&gt; click on &lt;strong&gt;Connect&lt;/strong&gt;.&lt;/p&gt;
&lt;p&gt;&lt;img src="https://devzone.nordicsemi.com/resized-image/__size/320x240/__key/support-attachments/beef5d1b77644c448dabff31668f3a47-03b17c4fe5f249bb94a4b3187c6f7777/pastedimage1551872379259v9.png" alt=" " /&gt;&lt;/p&gt;
&lt;p&gt;And click on the DFU button and Select distribution packet (ZIP)&lt;/p&gt;
&lt;p&gt;&lt;img src="https://devzone.nordicsemi.com/resized-image/__size/320x240/__key/support-attachments/beef5d1b77644c448dabff31668f3a47-03b17c4fe5f249bb94a4b3187c6f7777/pastedimage1551872425756v10.png" alt=" " /&gt;&lt;/p&gt;
&lt;p&gt;And select the &lt;strong&gt;&lt;/strong&gt;file &lt;strong&gt;app_dfu_package.zip&lt;/strong&gt;.&lt;/p&gt;
&lt;p&gt;After you have finished the device will reset and start advertising as &lt;strong&gt;Nordic_BMS&lt;/strong&gt;&lt;/p&gt;
&lt;p&gt;&lt;img src="https://devzone.nordicsemi.com/resized-image/__size/320x240/__key/support-attachments/beef5d1b77644c448dabff31668f3a47-03b17c4fe5f249bb94a4b3187c6f7777/pastedimage1551872548133v11.png" alt=" " /&gt;&lt;/p&gt;
&lt;p&gt;Does this make things a bit clearer?&lt;/p&gt;
&lt;p&gt;Best regards,&lt;/p&gt;
&lt;p&gt;Andreas&lt;/p&gt;&lt;div style="clear:both;"&gt;&lt;/div&gt;</description></item><item><title>RE: UNABLE TO GENERATE PRIVATE KEY</title><link>https://devzone.nordicsemi.com/thread/174397?ContentTypeID=1</link><pubDate>Tue, 05 Mar 2019 23:58:01 GMT</pubDate><guid isPermaLink="false">137ad170-7792-4731-bb38-c0d22fbe4515:cf616e47-e8ee-42b4-a43f-725c26a527d8</guid><dc:creator>arshdeep</dc:creator><description>&lt;p&gt;Also can you please tell the steps to erase the memory using command line tools (nrfprog -e) . Have never used command line tool. or is there any other way to do so ? if knew how to do it using nrfGo studio but now that does not work .&amp;nbsp;&lt;/p&gt;
&lt;p&gt;&lt;/p&gt;
&lt;p&gt;Thanks,&amp;nbsp;&lt;/p&gt;&lt;div style="clear:both;"&gt;&lt;/div&gt;</description></item><item><title>RE: UNABLE TO GENERATE PRIVATE KEY</title><link>https://devzone.nordicsemi.com/thread/174349?ContentTypeID=1</link><pubDate>Tue, 05 Mar 2019 16:07:32 GMT</pubDate><guid isPermaLink="false">137ad170-7792-4731-bb38-c0d22fbe4515:74f64844-5a4e-4be2-b2e4-db34a2d76730</guid><dc:creator>arshdeep</dc:creator><description>&lt;p&gt;How do I build the bootloader using the private key? it should be the public key right ??&lt;/p&gt;
&lt;p&gt;As I told you, I did try this procedure once but now every time I flash (with normal&amp;nbsp;SES IDE using a USB cable, not even with dfu)&amp;nbsp;any program from ble_peripheral example, I end up in a DFU mode Though it works fine if I flash any program from peripheral example.&lt;/p&gt;
&lt;p&gt;&lt;/p&gt;
&lt;p&gt;see in the attached pictures, I flashed ble_app_bms example&amp;nbsp;but the board is advertising as DfuTarg&lt;/p&gt;
&lt;p&gt;&lt;img src="https://devzone.nordicsemi.com/resized-image/__size/640x480/__key/communityserver-discussions-components-files/4/pastedimage1551801824463v1.png" alt=" " /&gt;&lt;/p&gt;
&lt;p&gt;&lt;img src="https://devzone.nordicsemi.com/resized-image/__size/640x480/__key/communityserver-discussions-components-files/4/pastedimage1551801949135v2.png" alt=" " /&gt;&lt;/p&gt;&lt;div style="clear:both;"&gt;&lt;/div&gt;</description></item><item><title>RE: UNABLE TO GENERATE PRIVATE KEY</title><link>https://devzone.nordicsemi.com/thread/174195?ContentTypeID=1</link><pubDate>Tue, 05 Mar 2019 09:36:25 GMT</pubDate><guid isPermaLink="false">137ad170-7792-4731-bb38-c0d22fbe4515:90296c82-b4eb-4fa8-8f52-ab537527394e</guid><dc:creator>AndreasF</dc:creator><description>&lt;p&gt;Hi.&lt;/p&gt;
&lt;p&gt;Sorry about the confusion, I wrote wrong in step one, i should have been &amp;quot;build&amp;quot;, and then you could program it later.&lt;/p&gt;
&lt;p&gt;If you use your phone, then you don&amp;#39;t need a second board, I thought that you had two boards, sorry about that.&lt;/p&gt;
&lt;p&gt;nRFgoStudio is outdated, so you should not use that. You should use &lt;a href="https://www.nordicsemi.com/Software-and-Tools/Development-Tools/nRF-Connect-for-desktop/Download#infotabs"&gt;nRF Connect for Desktop&lt;/a&gt; and the &lt;a href="https://www.nordicsemi.com/DocLib/Content/User_Guides/nc_programmer/latest/UG/nrf_connect_programmer/ncp_introduction"&gt;nRF Connect Programmer Application.&lt;/a&gt;&lt;/p&gt;
&lt;p&gt;I did the procedure with my mobile phone now, and it succeeded.&lt;/p&gt;
&lt;p&gt;I built the bootloader with the private key and programmed it onto the board.&lt;/p&gt;
&lt;p&gt;I then built the blinky application.&lt;/p&gt;
&lt;p&gt;I then created the DFU packet with the command in my previous reply.&lt;/p&gt;
&lt;p&gt;And then I did as you show in your pictures and selected the &lt;strong&gt;zip file&lt;/strong&gt; I generated.&lt;/p&gt;
&lt;p&gt;&lt;img alt=" " src="https://devzone.nordicsemi.com/resized-image/__size/320x240/__key/support-attachments/beef5d1b77644c448dabff31668f3a47-03b17c4fe5f249bb94a4b3187c6f7777/dfu_5F00_over_5F00_ble_5F00_phone.jpg" /&gt;&lt;/p&gt;
&lt;p&gt;When I finished, the board resets and LED 1 is on.&lt;/p&gt;
&lt;p&gt;Does this happen with your board?&lt;/p&gt;
&lt;p&gt;Best regards,&lt;/p&gt;
&lt;p&gt;Andreas&lt;/p&gt;&lt;div style="clear:both;"&gt;&lt;/div&gt;</description></item><item><title>RE: UNABLE TO GENERATE PRIVATE KEY</title><link>https://devzone.nordicsemi.com/thread/174105?ContentTypeID=1</link><pubDate>Mon, 04 Mar 2019 23:58:54 GMT</pubDate><guid isPermaLink="false">137ad170-7792-4731-bb38-c0d22fbe4515:2ad3a841-a2ad-4fc1-8191-77ed77977769</guid><dc:creator>arshdeep</dc:creator><description>&lt;p&gt;Hi Andreas,&lt;/p&gt;
&lt;p&gt;&lt;/p&gt;
&lt;p&gt;1) Program the bootloader found in the folder&lt;strong&gt;\examples\dfu\secure_bootloader\pca10056_ble_debug&lt;/strong&gt;&lt;span&gt;&amp;nbsp;&lt;/span&gt;with the private key you generated. : &lt;span style="text-decoration:underline;"&gt;You mean public_key.c right ??? and not the private key .&amp;nbsp;&lt;/span&gt;&lt;/p&gt;
&lt;p&gt;&lt;span&gt;5) Program the bootloader from step 1. :&lt;span style="text-decoration:underline;"&gt; Program the bootloader again? I did not understand this . should I program the bootloader in the second board ?&amp;nbsp;&lt;/span&gt;&lt;/span&gt;&lt;/p&gt;
&lt;p&gt;&lt;span&gt;6) Open nRF Connect Bluetooth Low Energy and try to do the DFU from your second board. &lt;span style="text-decoration:underline;"&gt;How to do the DFU using the second board ? I do not know. Do you have any link where i can learn how to do DFU using second board.&amp;nbsp;&lt;/span&gt;&lt;/span&gt;&lt;/p&gt;
&lt;p&gt;&lt;span&gt;&lt;/span&gt;&lt;/p&gt;
&lt;p&gt;&lt;span&gt;Also, my nrfGo studio is not able to detect boards :&lt;/span&gt;&lt;/p&gt;
&lt;p&gt;&lt;span&gt;&lt;img src="https://devzone.nordicsemi.com/resized-image/__size/640x480/__key/communityserver-discussions-components-files/4/pastedimage1551741505083v2.png" alt=" " /&gt;&lt;/span&gt;&lt;/p&gt;
&lt;p&gt;&lt;span&gt;It used to work fine in past. I tried uninstalling and installing it again. Did not work. Does this give any clues for DFU ?&lt;/span&gt;&lt;/p&gt;
&lt;p&gt;&lt;span&gt;&lt;/span&gt;&lt;/p&gt;
&lt;p&gt;&lt;span&gt;Also please check the steps that i do when connected through nrfConnect app:&lt;/span&gt;&lt;/p&gt;
&lt;p&gt;&lt;span&gt;&lt;img src="https://devzone.nordicsemi.com/resized-image/__size/640x480/__key/communityserver-discussions-components-files/4/pastedimage1551741687826v3.png" alt=" " /&gt;&lt;/span&gt;&lt;/p&gt;
&lt;p&gt;&lt;span&gt;&lt;img src="https://devzone.nordicsemi.com/resized-image/__size/640x480/__key/communityserver-discussions-components-files/4/pastedimage1551741712744v4.png" alt=" " /&gt;&lt;/span&gt;&lt;/p&gt;
&lt;p&gt;&lt;span&gt;&lt;/span&gt;&lt;/p&gt;
&lt;p&gt;&lt;span&gt;&lt;/span&gt;&lt;/p&gt;
&lt;p&gt;&lt;span&gt;&lt;/span&gt;&lt;/p&gt;&lt;div style="clear:both;"&gt;&lt;/div&gt;</description></item><item><title>RE: UNABLE TO GENERATE PRIVATE KEY</title><link>https://devzone.nordicsemi.com/thread/173944?ContentTypeID=1</link><pubDate>Mon, 04 Mar 2019 11:40:33 GMT</pubDate><guid isPermaLink="false">137ad170-7792-4731-bb38-c0d22fbe4515:3bc7e3f0-f5ea-4d08-8f17-c967476a2cd4</guid><dc:creator>AndreasF</dc:creator><description>&lt;p&gt;Hi Arshdeep.&lt;/p&gt;
&lt;p&gt;Can you try to do it the following way:&lt;/p&gt;
&lt;p&gt;1) Program the bootloader found in the folder&lt;strong&gt; \examples\dfu\secure_bootloader\pca10056_ble_debug&lt;/strong&gt; with the private key you generated.&lt;/p&gt;
&lt;p&gt;2) Compile the project found in the folder &lt;strong&gt;\examples\ble_peripheral\ble_app_blinky\pca10056&lt;/strong&gt;.&lt;/p&gt;
&lt;p&gt;3) Take the &lt;strong&gt;.hex file&lt;/strong&gt; from &lt;strong&gt;step 2&lt;/strong&gt; and generate the DFU packet with the private key from &lt;strong&gt;step 1.&lt;/strong&gt;&lt;/p&gt;
&lt;p&gt;&lt;span&gt;nrfutil pkg generate --hw-version 52 --application-version 1 --application ble_app_blinky_pca10056_s140.hex --sd-req 0xA9 --key-file private.pem app_dfu_package.zip&lt;/span&gt;&lt;/p&gt;
&lt;p&gt;&lt;span&gt;4) Do a nrfjprog -e on the board to erase the pervious stored memory.&lt;/span&gt;&lt;/p&gt;
&lt;p&gt;&lt;span&gt;5) Program the bootloader from step 1.&lt;/span&gt;&lt;/p&gt;
&lt;p&gt;&lt;span&gt;6) Open nRF Connect Bluetooth Low Energy and try to do the DFU from your second board.&lt;/span&gt;&lt;/p&gt;
&lt;p&gt;&lt;span&gt;Can you post some screenshots and log of the process? Does this work?&lt;/span&gt;&lt;/p&gt;
&lt;p&gt;&lt;span&gt;Best regards,&lt;/span&gt;&lt;/p&gt;
&lt;p&gt;&lt;span&gt;Andreas&lt;/span&gt;&lt;/p&gt;&lt;div style="clear:both;"&gt;&lt;/div&gt;</description></item><item><title>RE: UNABLE TO GENERATE PRIVATE KEY</title><link>https://devzone.nordicsemi.com/thread/173913?ContentTypeID=1</link><pubDate>Mon, 04 Mar 2019 10:09:02 GMT</pubDate><guid isPermaLink="false">137ad170-7792-4731-bb38-c0d22fbe4515:4b59198c-a0e4-4604-86e5-4fef212f71aa</guid><dc:creator>arshdeep</dc:creator><description>&lt;p&gt;Hi Andreas&lt;/p&gt;
&lt;p&gt;&lt;/p&gt;
&lt;p&gt;I did try with bsp example to check if the issue is in softdevice but the error was same.&amp;nbsp;&lt;/p&gt;
&lt;p&gt;&lt;/p&gt;
&lt;p&gt;Thanks&lt;/p&gt;
&lt;p&gt;Arshdeep&lt;/p&gt;&lt;div style="clear:both;"&gt;&lt;/div&gt;</description></item><item><title>RE: UNABLE TO GENERATE PRIVATE KEY</title><link>https://devzone.nordicsemi.com/thread/173890?ContentTypeID=1</link><pubDate>Mon, 04 Mar 2019 09:09:31 GMT</pubDate><guid isPermaLink="false">137ad170-7792-4731-bb38-c0d22fbe4515:527fcc9e-15be-42f3-b37c-d43b749b0250</guid><dc:creator>AndreasF</dc:creator><description>&lt;p&gt;Hi.&lt;/p&gt;
&lt;p&gt;Can you try to create a DFU packet and add a compiled self compiled version of the blinky project? And don&amp;#39;t merge it with the SoftDevice.&lt;/p&gt;
&lt;p&gt;Do you get the error then?&lt;/p&gt;
&lt;p&gt;Best regards,&lt;/p&gt;
&lt;p&gt;Andreas&lt;/p&gt;&lt;div style="clear:both;"&gt;&lt;/div&gt;</description></item><item><title>RE: UNABLE TO GENERATE PRIVATE KEY</title><link>https://devzone.nordicsemi.com/thread/173751?ContentTypeID=1</link><pubDate>Fri, 01 Mar 2019 15:37:23 GMT</pubDate><guid isPermaLink="false">137ad170-7792-4731-bb38-c0d22fbe4515:312258a9-820d-4fa5-982d-f6111f216a83</guid><dc:creator>arshdeep</dc:creator><description>&lt;p&gt;&lt;span&gt;nrfutil pkg generate --hw-version 52 --application-version 3 --application ble_app_blinky_pca10056_s140.hex --sd-req 0xA9 --key-file private.pem app_dfu_package.zip&lt;/span&gt;&lt;/p&gt;&lt;div style="clear:both;"&gt;&lt;/div&gt;</description></item><item><title>RE: UNABLE TO GENERATE PRIVATE KEY</title><link>https://devzone.nordicsemi.com/thread/173615?ContentTypeID=1</link><pubDate>Fri, 01 Mar 2019 07:27:58 GMT</pubDate><guid isPermaLink="false">137ad170-7792-4731-bb38-c0d22fbe4515:ac2e863c-485a-45af-a2ca-25c0c84af840</guid><dc:creator>AndreasF</dc:creator><description>&lt;p&gt;Hi.&lt;/p&gt;
&lt;p&gt;Could you please post the &lt;strong&gt;nrfutil command&lt;/strong&gt; that you used to generate the DFU packet? :-)&lt;/p&gt;
&lt;p&gt;Best regards,&lt;/p&gt;
&lt;p&gt;Andreas&lt;/p&gt;&lt;div style="clear:both;"&gt;&lt;/div&gt;</description></item><item><title>RE: UNABLE TO GENERATE PRIVATE KEY</title><link>https://devzone.nordicsemi.com/thread/173575?ContentTypeID=1</link><pubDate>Thu, 28 Feb 2019 21:57:36 GMT</pubDate><guid isPermaLink="false">137ad170-7792-4731-bb38-c0d22fbe4515:3c444729-c6d6-4144-89ed-d4981c5dd8bf</guid><dc:creator>arshdeep</dc:creator><description>&lt;p&gt;Thanks Andreas, I was able to generate the zip folder using the nrfutil but now i am running into 2 new issue -&amp;gt;&lt;/p&gt;
&lt;p&gt;1) After uploading the DFU.zip folder to nrf52840 DK from nrf Connect app, it does not run my application and kind of erases everything from board. The upload goes till 100% and seems like it did upload it successfully.&amp;nbsp;&lt;/p&gt;
&lt;p&gt;2) After I upload the DFU.zip folder, every time i try to flash another program using SES,&amp;nbsp; it keeps on going in DFU mode. I am unable to exit from DFU mode.&amp;nbsp;&lt;/p&gt;
&lt;p&gt;&lt;/p&gt;
&lt;p&gt;Please Suggest .&amp;nbsp;&lt;/p&gt;
&lt;p&gt;Regards,&amp;nbsp;&lt;/p&gt;&lt;div style="clear:both;"&gt;&lt;/div&gt;</description></item><item><title>RE: UNABLE TO GENERATE PRIVATE KEY</title><link>https://devzone.nordicsemi.com/thread/173371?ContentTypeID=1</link><pubDate>Thu, 28 Feb 2019 06:19:50 GMT</pubDate><guid isPermaLink="false">137ad170-7792-4731-bb38-c0d22fbe4515:31a494f1-84b6-46d3-a39a-3f8547a0eed1</guid><dc:creator>AndreasF</dc:creator><description>&lt;p&gt;Hi&lt;/p&gt;
[quote user="arshdeep"]Then created a zip folder in Desktop, DFU.zip . Copied the hex file from example SDK ble_app_blinky_pca10056_s140.hex into DFU.zip folder and also copied the private.key in the same folder.&amp;nbsp;[/quote]
&lt;p&gt;&amp;nbsp;Which command did you use in CMD? :-) &lt;/p&gt;
&lt;p&gt;You have to use &lt;strong&gt;&lt;a href="https://www.nordicsemi.com/DocLib/Content/User_Guides/nrfutil/latest/UG/nrfutil/nrfutil_pkg"&gt;nrfutil&lt;/a&gt; &lt;/strong&gt;to generate a DFU packet.&lt;/p&gt;
&lt;p&gt;Best regards,&lt;/p&gt;
&lt;p&gt;Andreas&lt;/p&gt;&lt;div style="clear:both;"&gt;&lt;/div&gt;</description></item><item><title>RE: UNABLE TO GENERATE PRIVATE KEY</title><link>https://devzone.nordicsemi.com/thread/173338?ContentTypeID=1</link><pubDate>Wed, 27 Feb 2019 23:25:35 GMT</pubDate><guid isPermaLink="false">137ad170-7792-4731-bb38-c0d22fbe4515:eb6e1303-61a6-4105-81ba-45878f1637dd</guid><dc:creator>arshdeep</dc:creator><description>&lt;p&gt;Yes Of course.&amp;nbsp;&lt;/p&gt;
&lt;p&gt;&lt;strong&gt;A1. Generate your own private key : Generated&amp;nbsp;&lt;/strong&gt;&lt;/p&gt;
&lt;p&gt;&lt;strong&gt;A2. Generate your public key based on your private key : Generated&lt;/strong&gt;&lt;/p&gt;
&lt;p&gt;&lt;strong&gt;B1. Compile the uECC library : Compiled, looks like this :&lt;img height="184" src="https://devzone.nordicsemi.com/resized-image/__size/320x240/__key/communityserver-discussions-components-files/4/pastedimage1551309368024v1.png" width="249" alt=" " /&gt;&lt;/strong&gt;&lt;/p&gt;
&lt;p&gt;&lt;strong&gt;Then went inside folder&amp;nbsp;\nRF5_SDK_15.0.0_a53641a\external\micro-ecc\nrf52nf_keil\armgcc and typed make.&lt;/strong&gt;&lt;/p&gt;
&lt;p&gt;&lt;strong&gt;B2. Copy the public_key.c file : copied the public_key.c file here \nRF5_SDK_15.0.0_a53641a\examples\dfu\secure_bootloader and built the example successfully.&lt;/strong&gt;&lt;/p&gt;
&lt;p&gt;&lt;strong&gt;Then created a zip folder in Desktop, DFU.zip . Copied the hex file from example SDK ble_app_blinky_pca10056_s140.hex into DFU.zip folder and also copied the private.key in the same folder.&amp;nbsp;&lt;/strong&gt;&lt;/p&gt;
&lt;p&gt;&lt;strong&gt;Then tried to send this DFU.zip folder using nrfConnect app.&amp;nbsp;&lt;/strong&gt;&lt;/p&gt;
&lt;p&gt;&lt;strong&gt;Thanks,&amp;nbsp;&lt;/strong&gt;&lt;/p&gt;&lt;div style="clear:both;"&gt;&lt;/div&gt;</description></item><item><title>RE: UNABLE TO GENERATE PRIVATE KEY</title><link>https://devzone.nordicsemi.com/thread/173156?ContentTypeID=1</link><pubDate>Wed, 27 Feb 2019 06:24:22 GMT</pubDate><guid isPermaLink="false">137ad170-7792-4731-bb38-c0d22fbe4515:4a40a300-7ef9-449e-a25d-d1edc60efae1</guid><dc:creator>AndreasF</dc:creator><description>&lt;p&gt;Hi.&lt;/p&gt;
&lt;p&gt;How did you generate the DFU.zip file? What command did you run?&lt;/p&gt;
&lt;p&gt;Could you please explain every step you took from &lt;strong&gt;start&lt;/strong&gt; until you &lt;strong&gt;generated the DFU.zip&lt;/strong&gt; file :-)&lt;/p&gt;
&lt;p&gt;Best regards,&lt;/p&gt;
&lt;p&gt;Andreas&lt;/p&gt;&lt;div style="clear:both;"&gt;&lt;/div&gt;</description></item><item><title>RE: UNABLE TO GENERATE PRIVATE KEY</title><link>https://devzone.nordicsemi.com/thread/173137?ContentTypeID=1</link><pubDate>Wed, 27 Feb 2019 01:25:55 GMT</pubDate><guid isPermaLink="false">137ad170-7792-4731-bb38-c0d22fbe4515:41f6515d-d585-47b8-a54a-4723811c5c6f</guid><dc:creator>arshdeep</dc:creator><description>&lt;p&gt;Thanks Andreas, It worked with Python2.7&amp;nbsp;&lt;/p&gt;
&lt;p&gt;i followed this tutorial:&amp;nbsp;&lt;a href="https://devzone.nordicsemi.com/b/blog/posts/getting-started-with-nordics-secure-dfu-bootloader"&gt; https://devzone.nordicsemi.com/b/blog/posts/getting-started-with-nordics-secure-dfu-bootloader&lt;/a&gt;&lt;/p&gt;
&lt;p&gt;I tried sending DFU.zip file using nrfConnect app but the application was not able to send the file.&amp;nbsp;&lt;/p&gt;
&lt;p&gt;&lt;img height="188" src="https://devzone.nordicsemi.com/resized-image/__size/320x240/__key/communityserver-discussions-components-files/4/pastedimage1551230554947v1.png" width="165" alt=" " /&gt;&lt;/p&gt;
&lt;p&gt;&lt;/p&gt;
&lt;p&gt;See the attached DFU.zip generated by me.&amp;nbsp;&lt;/p&gt;
&lt;p&gt;&lt;a href="https://devzone.nordicsemi.com/cfs-file/__key/communityserver-discussions-components-files/4/8270.DFU.zip"&gt;devzone.nordicsemi.com/.../8270.DFU.zip&lt;/a&gt;&lt;/p&gt;
&lt;p&gt;&lt;/p&gt;
&lt;p&gt;can you suggest where i could have been wrong in the steps ?&amp;nbsp;&lt;/p&gt;
&lt;p&gt;&lt;/p&gt;
&lt;p&gt;Thanks,&amp;nbsp;&lt;/p&gt;&lt;div style="clear:both;"&gt;&lt;/div&gt;</description></item></channel></rss>