• State Verified Answer
  • Replies 66 replies
  • Subscribers 65 subscribers
  • Views 7601 views
  • Users 0 members are here
Attachments (4) Download All
Nordic Case Info
  • Case ID: 292222
Options

nrf52840 S140 Central DFU Bluetooth Zephyr 2.0.0 nrf52840 peripheral

DavidKaplan

We have nrf52840 S140 BLE Central device that currently connects to TI based sensors. I have implemented code that can upgrade those TI sensors' firmware using the TI BLE protocol.

Now we are developing our own BLE peripheral sensors also based on the nrf52840 but now using the newly supported Zephyr 2.0.0. RF connect stuff. I can update the sensors using the Nordic Android program (unauthenticated for now) and now need to implement upgrading BLE DFU using our central device which connects to a cellular gateway.

I do not want to reinvent the wheel, writing existing code, like I had to do with the TI sensors.

Could you point me to code that allows a Central device to update a peripheral device BLE DFU?

If not where can I look to reinvent another wheel?

Thanks David

Parents
  • 0

    Have a look at the sample Bluetooth: Central SMP Client

    Then use the SMP sever Sample on the Bluetooth Peripheral device

    Currently it is only possible to send the echo command from the Central SMP Client, so you would have to implement the other commands yourself, like upload, list, test and so on.. 

    Best regards,

    Simon

  • 0 in reply to Simon

    Now I have gotten back to this issue with our custom sensor hardware to arrive next week.

    I have used the Android nRF Toolbox app successfully to update an unsigned image whereas the Nordic DFU tool did not work.

    I understand that the Android apps use the SMP protocol that ties in with the img_mgmt libraries.

    Where can I find documentation on what the Android app does so I can reproduce it in c in my central device?

    Without any documentation it will be very hard for me to reverse engineer the Java somehow.

    I do not want to have to add more code in the sensor to handle a custom DFU if possible since it already exists and the Zephyr junk makes a giant image anyway.

    I saw a post with my exact request,  but I understand that it is not a priority issue.

     BLE DFU, MCU to MCU (Zephyr), GATT DFU SMP Service Clinet 

    I also saw a SoftDevice (not Zephyr) example post of what I need but uses the old DFU stuff I think and SoftDevice APIs

     Mesh DFU: Serial transfer of DFU archive 

    I need much more information to implement upload,list & test SMP commands that evidently exist in my sensor using the SMP server.

    Could it be that the Android app used some legacy DFU?

    Thanks David

  • 0 in reply to DavidKaplan
    DavidKaplan said:
    Where can I find documentation on what the Android app does so I can reproduce it in c in my central device?

    I would recommend you to use the nRF Connect Device Manager app. It is made for just this purpose, perform DFU updates using the mcumgr protocol. Here is the source code https://github.com/NordicSemiconductor/Android-nRF-Connect-Device-Manager

    Regarding documentation about this app, maybe take a look at the readme file: https://github.com/NordicSemiconductor/Android-nRF-Connect-Device-Manager#readme 

    To answer your question, you can find the list of commands you need to run in the smp_svr documentation. To summarize, these commands needs to run in this order from the central SMP Client sample:

    This is basically the commands you need to run to perform a DFU update

    You can try to make an attempt to merge these commands into the SMP Client sample, and let me know if you have issues, and I will try to assist. It is a little bit hectic now in support since a huge part of the support team are on summer vacation, but I can make an attempt on this if you would like after my vacation ends around the 15th of august.

    However, you don't really need to use the mcumgr protocol to perform the update. See my explanation in this ticket:  RE: Update code via UART instead of FOTA nRF9160  

    If it's too difficuilt to implement the mcumgr command you can just use the approach I explained in this ticket

    In this ticket UART is used. However, this is just the transfer medium, so what I say is also valid for you.

    Best regards,

    Simon

  • 0 in reply to Simon

    Our hardware is supposed to arrive by the end of the day.

    Our Gateway, uses a host microcontroller with a cellular modem, connected by a uart serial channel to a MS88SF2 module with the nRF52840 chip as a Central device.
    The nRF52840 has no external storage.
    When updating TI sensors, the image information is first sent, which is used to start the TI OAD.
    Then, I stream the new image bytes to a 64K ram buffer on the nRF52840 while it writes TI BLE OAD packets.
    I must keep the ram buffer filled or the TI OAD process will fail with a timeout.

    It does look very daunting to reconstruct the Kotlin code using the SMP protocol in my Central code.
    I am still exploring my different options but I was thinking of trying something based on the multi-NUS-master example.

    Very roughly something like this:
    1) The Central will receive an image update message with the new image information (size,crc,etc) and which Peripherals to update from its host.
    2) The Central will connect to all of its peripherals that need the image update.
    Every message below will be broadcast to all connected periperals.
    3) The Central will send a message to erase its slot#1 image
    Is Slot#1 correct?
    What API should I call?
    4) The Central will send image block packets to fill up a 64K ram buffer.
    5) The Central will send a message to flash the 64K to Slot#1 at the specified offset.
    What API should I call?
    6) The Central will continue with steps 4) & 5) until the whole image has been written.
    7) The Central will send a message to get the image's hash.
    What API should I call?
    8) The Central will send a message to "test" the image
    What API should I call?
    9) The Central will send a message to reset the peripheral.
    What API should I call?
    10) Upon reconnection, the Central will send a message to "confirm" the image.

    If the nRF Toolbox app is able to upgrade the peripheral, do I need any new prog.confg defines for the suggested API?

    Another quick question that is related.
    If I design the project with a mode that leaves the Peripherals always connected,
    I understand that I may be able to get an even lower Peripheral current drain.
    If a Peripheral is at the edge of the BLE signal range or there is a lot of interference ,
    will I end up wasting a lot for current?

    Thanks David

Reply
  • 0 in reply to Simon

    Our hardware is supposed to arrive by the end of the day.

    Our Gateway, uses a host microcontroller with a cellular modem, connected by a uart serial channel to a MS88SF2 module with the nRF52840 chip as a Central device.
    The nRF52840 has no external storage.
    When updating TI sensors, the image information is first sent, which is used to start the TI OAD.
    Then, I stream the new image bytes to a 64K ram buffer on the nRF52840 while it writes TI BLE OAD packets.
    I must keep the ram buffer filled or the TI OAD process will fail with a timeout.

    It does look very daunting to reconstruct the Kotlin code using the SMP protocol in my Central code.
    I am still exploring my different options but I was thinking of trying something based on the multi-NUS-master example.

    Very roughly something like this:
    1) The Central will receive an image update message with the new image information (size,crc,etc) and which Peripherals to update from its host.
    2) The Central will connect to all of its peripherals that need the image update.
    Every message below will be broadcast to all connected periperals.
    3) The Central will send a message to erase its slot#1 image
    Is Slot#1 correct?
    What API should I call?
    4) The Central will send image block packets to fill up a 64K ram buffer.
    5) The Central will send a message to flash the 64K to Slot#1 at the specified offset.
    What API should I call?
    6) The Central will continue with steps 4) & 5) until the whole image has been written.
    7) The Central will send a message to get the image's hash.
    What API should I call?
    8) The Central will send a message to "test" the image
    What API should I call?
    9) The Central will send a message to reset the peripheral.
    What API should I call?
    10) Upon reconnection, the Central will send a message to "confirm" the image.

    If the nRF Toolbox app is able to upgrade the peripheral, do I need any new prog.confg defines for the suggested API?

    Another quick question that is related.
    If I design the project with a mode that leaves the Peripherals always connected,
    I understand that I may be able to get an even lower Peripheral current drain.
    If a Peripheral is at the edge of the BLE signal range or there is a lot of interference ,
    will I end up wasting a lot for current?

    Thanks David

Children
  • 0 in reply to DavidKaplan

    Hello and sorry for the delay. I've been gone on vacation the last two weeks.

    Could you update me on the current state of this ticket? Then I will help you accordingly.

    Best regards,

    Simon

  • 0 in reply to Simon

    I have been working on other things in this project and on other more urgent projects changes and fixes. 

    Now I am back on this and still need to get this working somehow.

    If you could just write the correct APIs in every step, I may be able to advance this. quicker.

    One of my peripheral sensors stopped working when trying to measure its current.

    It is not detected by the SDK. Is there any way to brick a nRF52840 or have I just damaged a pin?

    Thanks David

  • 0 in reply to DavidKaplan
    DavidKaplan said:
    3) The Central will send a message to erase its slot#1 image
    Is Slot#1 correct?
    What API should I call?

    You should put the update into the secondary slot, so if you refer to the primary slot as slot#0 and the secondary slot as slot#1, then slot#1 is correct yes.

    Regarding what API to call to erase the secondary slot, you can take a look at the function img_mgmt_upload()-->img_mgmt_impl_erase_image_data() (called in response to an mcumgr upload command), as you can see, it uses the function flash_area_erase() to erase the secondary slot.

    DavidKaplan said:
    5) The Central will send a message to flash the 64K to Slot#1 at the specified offset.
    What API should I call?

    Take a look at the same function img_mgmt_impl_erase_image_data(), as mentioned above. It will write to the secondary slot using img_mgmt_impl_write_image_data()-->flash_img_buffered_write()-->stream_flash_buffered_write()

    If using fota_download+dfu_target_mcuboot (used by nRF91 to update appl.) the same function is used: dfu_target_write-->dfu_target_mcuboot_write()-->

    stream_flash_buffered_write().
    I guess it could work to just use flash_map.h-->flash_area_write() or flash.h-->flash_write, but as mentioned in the documentation, there are some advantages with using the Stream Flash API:
    "One typical use of a stream write operation is when receiving a new firmware image to be used in a DFU operation.

    There are several reasons why one might want to use buffered writes instead of writing the data directly as it is made available. Some devices have hardware limitations which does not allow flash writes to be performed in parallel with other operations, such as radio RX and TX. Also, fewer write operations result in faster response times seen from the application."

    DavidKaplan said:
    7) The Central will send a message to get the image's hash.
    What API should I call?

    Check how it's done in the function \zephyr\subsys\mgmt\mcumgr\lib\cmd\img_mgmt\src\img_mgmt.c-->img_mgmt_read_info(), which will read the version and build hash from the specified image slot.

    DavidKaplan said:
    8) The Central will send a message to "test" the image
    What API should I call?

    Check out how how the image management library does it: \zephyr\subsys\mgmt\mcumgr\lib\cmd\img_mgmt\include\img_mgmt\img_mgmt.h-->img_mgmt_state_set_pending()-->img_mgmt_impl_write_pending()-->boot_request_upgrade_multi()

    So you can set the image to a "test" (run once and then revert) state by running boot_request_upgrade_multi(int image_index, int permanent) with permanent=0, or confirm the image by setting permanent=1 (run image forever).

    DavidKaplan said:
    9) The Central will send a message to reset the peripheral.
    What API should I call?

    You can use \zephyr\lib\os\reboot.c-->sys_reboot() for this.

    DavidKaplan said:
    10) Upon reconnection, the Central will send a message to "confirm" the image.

    You can do this by running boot_write_img_confirmed() from within the app itself, like it's done in the http_update sample: https://github.com/nrfconnect/sdk-nrf/blob/v2.0.2/samples/nrf9160/http_update/application_update/src/main.c#L60 

    DavidKaplan said:
    If the nRF Toolbox app is able to upgrade the peripheral, do I need any new prog.confg defines for the suggested API?

    If you wan't to perform a DFU app from the phone using custom BLE commands and the APIs I suggested above, you can use the nRF Connect for Mobile app: https://www.nordicsemi.com/Products/Development-tools/nrf-connect-for-mobile 

    If you want to perfom a DFU using mcumgr protocol, I suggest using the nRF Connect Device Manager app and follow the DFU guide.

    DavidKaplan said:
    Another quick question that is related.
    If I design the project with a mode that leaves the Peripherals always connected,
    I understand that I may be able to get an even lower Peripheral current drain.
    If a Peripheral is at the edge of the BLE signal range or there is a lot of interference ,
    will I end up wasting a lot for current?

    This is not my area of expertise. Could you open a new ticket and ask about it there. I think you will get better help then.

    Best regards,

    Simon

  • 0 in reply to Simon

    I successfully upgraded a unit once but did not saved immediately the code and evidently changed something and it now fails when calling img_mgmt_impl_write_pending().

    I guess I could build a small project for the nRF52840-DK  using the serial uart interface.

    It is hard to debug break with the BLE running.

    In my main program when running the debugger it always says the image is not confirmed.

    I expected this to occur just once after DFU.

      //---------------------------------------------------------------------------
  // DFU upgraded and not confirmed, confirm
  //---------------------------------------------------------------------------
  if (!boot_is_img_confirmed()){
    err = boot_write_img_confirmed();
	  if (err) {
		  d_printf(LINE_INFO,kDbg_Error|kDbg_Display,"BootConfirmErr:%d",err);
    }else{
          d_printf(LINE_INFO,kDbg_Error|kDbg_Display,"BootConfirmed");
    }
  }

    Here is my DFU code if you see anything wrong.

    I could not find a way to set the global area_id except for setting it myself.

    I would think that some function should set it.

    g_img_mgmt_state.area_id = UPLOAD_FLASH_AREA_ID;

    Fullscreen ami_dfu.c Download 
    #include <stddef.h>
#include <string.h>
#include <stdio.h>
#include <errno.h>
#include <kernel.h>
#include <zephyr.h>

#include <sys/printk.h>

#include <zcbor_encode.h>
#include <zcbor_decode.h>
#include <zcbor_common.h>

#include <zephyr/bluetooth/bluetooth.h>
#include <zephyr/bluetooth/hci.h>
#include <zephyr/bluetooth/hci_vs.h>
#include <zephyr/bluetooth/conn.h>
#include <zephyr/bluetooth/uuid.h>
#include <zephyr/bluetooth/gatt.h>
#include <bluetooth/gatt_dm.h>
#include <zephyr/sys/byteorder.h>
#include <bluetooth/services/dfu_smp.h>
#include <sys/reboot.h>
#include <zephyr/sys/ring_buffer.h>

#include <dfu/mcuboot.h>
#include <zephyr/dfu/mcuboot.h>
#include <dfu/dfu_target.h>
#include <dfu/dfu_target_stream.h>
#include <dfu/dfu_target_mcuboot.h>

#include <img_mgmt/img_mgmt_impl.h>
#include <img_mgmt/img_mgmt.h>
#include <img_mgmt/image.h>
#include <storage/flash_map.h>
#include <dfu/flash_img.h>
#include <devicetree.h>

#if FLASH_AREA_LABEL_EXISTS(image_1)
	#define UPLOAD_FLASH_AREA_ID FLASH_AREA_ID(image_1)
#endif


#include "aqua_def.h"
#include "d_printf.h"
#include "ami_ble.h"
#include "ami_main_serv.h"
#include "ami_setup_serv.h"
#include "ami_learn_serv.h"
#include "ami_transfer_serv.h"
#include "ami_timer.h"
#include "ami_dfu.h"
#include "ami_watchdog.h"

//-----------------------------------------------------------------------------
// define Ring buffers
//-----------------------------------------------------------------------------
RING_BUF_ITEM_DECLARE_SIZE(dfu_ring_buf, AMI_DFU_RING_BUF_SIZE);

//-----------------------------------------------------------------------------
// Variables
//-----------------------------------------------------------------------------
ami_dfu_state_struct    *dfu_state = NULL;
static struct	flash_img_context flash_img;

//-----------------------------------------------------------------------------
// ami_dfu_HandlePacket
//  Description
//   Parses an incoming BLE image packet
//  Parameters
//  Returns
//   0 = OK
//-----------------------------------------------------------------------------
int ami_dfu_HandlePacket(uint8_t *buf,uint16_t buf_pos,uint16_t len)
{
  //---------------------------------------------------------------------------
  // transfer_receive_cb
  //---------------------------------------------------------------------------
  int       err = 0;
  uint16_t  data_len;
  //---------------------------------------------------------------------------
  // FileRxOffset
  //---------------------------------------------------------------------------
  dfu_state->FileRxOffset.bytes[LSB_LO_BYTE] = buf[buf_pos++];
  dfu_state->FileRxOffset.bytes[LSB_HI_BYTE] = buf[buf_pos++];
  dfu_state->FileRxOffset.bytes[MSB_LO_BYTE] = buf[buf_pos++];
  dfu_state->FileRxOffset.bytes[MSB_HI_BYTE] = buf[buf_pos++];
  //---------------------------------------------------------------------------
  // If FileRxOffset==0 then FileSize sent
  //---------------------------------------------------------------------------
  if (!dfu_state->FileRxOffset.ulong){
    dfu_state->FileSize.bytes[LSB_LO_BYTE] = buf[buf_pos++];
    dfu_state->FileSize.bytes[LSB_HI_BYTE] = buf[buf_pos++];
    dfu_state->FileSize.bytes[MSB_LO_BYTE] = buf[buf_pos++];
    dfu_state->FileSize.bytes[MSB_HI_BYTE] = buf[buf_pos++];
  }
  data_len = (len-buf_pos);
  //---------------------------------------------------------------------------
  // Something to write to Flash 
  //---------------------------------------------------------------------------
  if (data_len){
    //-------------------------------------------------------------------------
    // Store image data 
    //-------------------------------------------------------------------------
    if (dfu_state->FileRingWrOffset==dfu_state->FileRxOffset.ulong){
      uint16_t num_put = ring_buf_put(&dfu_ring_buf,&buf[buf_pos],data_len);
      if (num_put!=data_len) {
        dfu_state->err = AMI_DFU_CENTRAL_ERR_RING_OVERFLOW;
        d_printf(LINE_INFO,kDbg_Error|kDbg_General,"RingPut:%u Rx:%u Off:%ld",num_put,data_len,dfu_state->FileRxOffset.ulong);
        return err;
      }else{
            dfu_state->FileRingWrOffset += data_len;
      }
    }else{
          // This was a retry that the Central did not received an acknowledgemnet
    }
  }
  return err;
} // ami_dfu_HandlePacket

//-----------------------------------------------------------------------------
// ami_dfu_HandleBlock
//  Description
//   Handles the incoming DFU image block
//  Parameters
//  Returns
//  the offset to send back o the Central
//-----------------------------------------------------------------------------
uint32_t ami_dfu_HandleBlock(void)
{
  static   uint8_t wr_buf[CONFIG_IMG_BLOCK_BUF_SIZE];
  bool     bLast      = false;
  //---------------------------------------------------------------------------
  // If there was a fatal error, just return the last error
  //---------------------------------------------------------------------------
  if (dfu_state->err){
    return dfu_state->err;
  }
  //---------------------------------------------------------------------------
  // All bytes were received?
  //---------------------------------------------------------------------------
  bool bRxFinished = (dfu_state->FileRingWrOffset>=dfu_state->FileSize.ulong);
  do{
      //-----------------------------------------------------------------------
      // Peek and see how many bytes accumulated exist
      //-----------------------------------------------------------------------
      uint32_t accum_bytes = ring_buf_size_get(&dfu_ring_buf);
      //-----------------------------------------------------------------------
      // Wait to write until we have CONFIG_IMG_BLOCK_BUF_SIZE bytes or last packet 
      //-----------------------------------------------------------------------
      if (accum_bytes<CONFIG_IMG_BLOCK_BUF_SIZE && !bRxFinished){
        break;
      }
      //-----------------------------------------------------------------------
      // Don't write more than CONFIG_IMG_BLOCK_BUF_SIZE bytes at a time
      //-----------------------------------------------------------------------
      if (accum_bytes>CONFIG_IMG_BLOCK_BUF_SIZE){
        accum_bytes = CONFIG_IMG_BLOCK_BUF_SIZE;
      }
      //-----------------------------------------------------------------------
      // Calculate the number of bytes left to write to flash
      //-----------------------------------------------------------------------
      uint32_t bytes_to_wr = (dfu_state->FileSize.ulong-dfu_state->FileWrOffset);
      //-----------------------------------------------------------------------
      // Last block to write?
      //-----------------------------------------------------------------------
      if (accum_bytes>=bytes_to_wr){
        accum_bytes = bytes_to_wr;
        bLast       = true;
      }
      //-----------------------------------------------------------------------
      // Get the bytes from the ring buffer
      //-----------------------------------------------------------------------
      uint32_t data_len   = ring_buf_get(&dfu_ring_buf,wr_buf,accum_bytes);
      //-----------------------------------------------------------------------
      // Nothing to write?
      //-----------------------------------------------------------------------
      if (!data_len){        
        break;
      }
      //-----------------------------------------------------------------------
      // Write the data to the flash
      //-----------------------------------------------------------------------
      int err = img_mgmt_impl_write_image_data(dfu_state->FileWrOffset,wr_buf,data_len,bLast);
      if (err!=0) {
        dfu_state->err = AMI_DFU_CENTRAL_ERR_WR_BLOCK;
        d_printf(LINE_INFO,kDbg_Error|kDbg_General,"ImageWrErr:%d",err);
        return dfu_state->err;
      }else{
            //-----------------------------------------------------------------
            // Update last offset written
            //-----------------------------------------------------------------
            dfu_state->FileWrOffset += data_len;
            //-----------------------------------------------------------------
            // All of the image was written?
            //-----------------------------------------------------------------
            if (dfu_state->FileWrOffset>=dfu_state->FileSize.ulong){
              int image_slot = 1;
              struct image_version ver;
              uint8_t  hash;
              uint32_t flags;
              bool permanent = false;
              
              err = img_mgmt_read_info(image_slot,&ver,&hash,&flags);
              if (err==0){
                err = img_mgmt_impl_write_pending(image_slot,permanent);
                if (err==0){
                  d_printf(LINE_INFO,kDbg_Error|kDbg_General,"FinishedDFU");
                }else{
                      dfu_state->err = AMI_DFU_CENTRAL_ERR_SET_PENDING;                
                }
              }else{
                    dfu_state->err = AMI_DFU_CENTRAL_ERR_RD_INFO;
                    d_printf(LINE_INFO,kDbg_Error|kDbg_General,"ImageInfoErr:%d",err);
              }
              //---------------------------------------------------------------
              // Reset after reply
              //---------------------------------------------------------------
              ami_state->reset_secs = 2;
            }
      }
  }while (bRxFinished);
  return dfu_state->FileRxOffset.ulong;
} // ami_dfu_HandleBlock

//-----------------------------------------------------------------------------
// ami_dfu_Start
//  Description
//   Inits the dfu state and sets the dfu streaming buffer
//  Parameters
//  Returns
//   0 = OK
//-----------------------------------------------------------------------------
int ami_dfu_Start(void)
{
  //---------------------------------------------------------------------------
  // Clear dfu state
  //---------------------------------------------------------------------------
  memset(dfu_state,0,sizeof(ami_dfu_state_struct));
  //---------------------------------------------------------------------------
  // Reset dfu ring buffer
  //---------------------------------------------------------------------------
  ring_buf_reset(&dfu_ring_buf);
  //---------------------------------------------------------------------------
  // Erase upload slot
  //---------------------------------------------------------------------------
  int err = img_mgmt_impl_erase_slot();
  if (err!=0){
    //-------------------------------------------------------------------------
    // Reset after reply
    //-------------------------------------------------------------------------
    ami_state->reset_secs = 2;
    dfu_state->err = AMI_DFU_CENTRAL_ERR_ERASE;
    d_printf(LINE_INFO,kDbg_Error|kDbg_General,"ImageEraseErr:%d", err);
    return err;
  }      
  //---------------------------------------------------------------------------
  // Init Flash stream writer (CONFIG_IMG_BLOCK_BUF_SIZE)
  //---------------------------------------------------------------------------
  g_img_mgmt_state.area_id = UPLOAD_FLASH_AREA_ID;
  err = flash_img_init(&flash_img);
  if (err!=0){
    d_printf(LINE_INFO,kDbg_Error|kDbg_General,"FlashInitErr:%d", err);
    dfu_state->err = AMI_DFU_CENTRAL_ERR_IMAGE_INIT;
    //-------------------------------------------------------------------------
    // Reset after reply
    //-------------------------------------------------------------------------
    ami_state->reset_secs = 2;
    return err;
  }
  g_img_mgmt_state.area_id = UPLOAD_FLASH_AREA_ID;
  return err;
} // ami_dfu_Start

//-----------------------------------------------------------------------------
// ami_dfu_Init
//  Description
//   Alolocates memory
//  Parameters
//  Returns
//   0 = OK
//-----------------------------------------------------------------------------
int ami_dfu_Init(void)
{
  int err = 0;

  //---------------------------------------------------------------------------
  // Allocate memory
  //---------------------------------------------------------------------------
  dfu_state  = k_malloc(sizeof(ami_dfu_state_struct));
  while (!dfu_state);
  memset(dfu_state,0,sizeof(ami_dfu_state_struct));
  return err;
} // ami_dfu_Init

    Thanks David

  • 0 in reply to DavidKaplan

    Hello David, 

    I would just like to point you to this solution I just completed: https://github.com/simon-iversen/ncs_samples/tree/master/central_smp_client_dfu 

    With this sample you will be able to perform a DFU from one nRF52840DK to another nRF52840DK

    This sample seems to address the exact issue this post is about.

    Let me know if you still want me to look into your last questions.

    Best regards,

    Simon

    • Related