Reference Manual

Table Of Contents
2. during a reset and while restarting, a low signal has to be present on the BOOT pin of
the module to start it in bootloader mode
The bootloader mode has started successfully if LED_1 has turned on. After the boot-
loader has started successfully, the module goes into the advertising mode using the name
"DFUProteus-III". Now, any BLE device hosting an application that understands the com-
mands of the Nordic nRF52 BLE DFU Bootloader can connect in order to update the Proteus-
III firmware.
The DFU application of the used App (see Table
23
) is such an application. For more details,
please refer to chapter
14.2.1
. As soon as a connection has been set up, LED_1 turns off
again and LED_2 turns on.
The implemented Nordic nRF52 BLE DFU bootloader uses a dual bank
method to update the firmware. Thus, the old firmware is only replaced once
the new firmware has been transferred successfully. This prevents the module
from being flashed with a faulty firmware.
An OTA firmware update will take several minutes to be performed, the duration
is also dependent how much of the firmware shall be updated (application only
or complete update).
The max connection interval of the update service is set to 30ms. Please check
whether your mobile supports this speed.
This method is only applicable if the Proteus-III still contains an intact boot-
loader. In order to be able to recover a faulty module, we recommend to have
access to the relevant JTAG pins required to perform a wired firmware update.
Proteus-III reference manual version 0.11 © November 2019
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