Buttonless DFU - Consecutive flash will fail to ENTER_BOOTLOADER

[parco]

Steps to reproduce:

1. Flash softdevice_s132.hex
2. Flash bootloader_secure_ble_debug_with_bonds_s132.hex
3. Flash ble_app_buttonless_dfu_with_bonds_s132_with_setting_page.hex
4. Connect and bond with device using nRF-Connect
5. DFU and select ble_app_buttonless_dfu_with_bonds_s132_with_setting_page.zip
6. Note that the DFU is successful, and reconnect to device
7. Attempt step 5 again
8. Receive this error: "When writing 'ENTER_BOOTLOADER' command to Buttonless Characteristic of DFU Target: Operation code 1 (ENTER_BOOTLOADER) failed on DFU Target. Result code 4 (OPERATION_FAILED)"

This will continue to happen until there is a power cycle.

Please advise.

[bjorn-spockeli]

Hi Parco, I apologize for the late response. The DFU settings page should not be merged with the application when you create DFU images. The settings file should only be merged with the bootloader hex when you want to flash SD+BL+APP to the device and you want the device to jump to the application and not stay in bootloader mode.