RE: FLASHING THE HEX FILE

Rune Holmgren — Thu, 22 Mar 2018 09:19:12 GMT

When the bootloader start it will check the bootloader settings page to see if it has a valid application available in bank 0. If it does the bootloader will (unless you are holding a button or using the buttonless service) start the application. When you perform DFU to send the application to the device, the bootloader will update the settings page so that the application will be valid. If you want to flash an application to the device and have the bootloader running (useful both in development and production) you will have to generate a settings page and flash it to the device. nrfutil supports the command nrfutil settings generate which will create a settings page valid for the application you send in as an argument. See documentation in the link above for explanations and an example of use.

You will typically have a small script or some command line input which generates the settings page from the application hex and then flashes everything you need to the device. It just makes development simpler when you don't have to do each step manually every time you want to flash a new firmware.

Best regards,
Rune Holmgren