• @fanoush

    So here I come back to one point, if I can flash Espruino (older version) to nRF 51822 based fitness band.

    In my previous attempt to perform RE on tracker I destroyed SWD CLK test pad because of over heated soldering iron. No no more hardware hacking. So I started looking H Band Android application.

    I found very interesting things from the android app .

    It uses battery service and characteristics to communicate with firmware for most of the commands like setting alarms, entering in DFU mode. Yes it enters in the DFU mode by issuing codes to firmware and FW starts the DFU services. I successfully entered in DFU mode and exits after timeout using nodeJS code.

    I also observed in android app how app is sending dfu packets to device. The code using Nordic android library for DFU and seems does not use the secure dfu classes, although library does have the secure dfu class. More analysis will confirm this.

    So the questions are.

    1- Does it means that Bootloader is not a Nordic one and customised?
    2- assuming that original firmware is built using SDK 11 and not encrypted /no secure dfu, can I flash Espruino (version???) via OTA DFU? I can create flashing tool on android by taking help of existing hband app and D6 flasher app.

    3- Since I cannot do flash dump and only have original firmware, is there anything that can be to to get useful information?

    Abhinav

About

Avatar for Abhigkar @Abhigkar started