AN4486

The concept of OTA bootloading

DocID026293 Rev 2

5/29

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The concept of OTA bootloading

The OTA bootloader is essentially a tool that allows a slave device to receive a firmware

image over-the-air from a master device and write it into Flash memory. To put things in the

context of Bluetooth low energy, the OTA bootloader is a service offering its own

characteristics and can coexist with other services used by any given application running

on the BLE stack. In our implementation, the BLE master will be a combined system made

up of BlueNRG and BlueNRG-MS kits platforms connected to a PC through USB. The

BlueNRG or BlueNRG-MS platform is driven by the BlueNRG GUI running on the

connected PC. This choice allows us to benefit from numerous resources available from

the PC, specifically with regard to compilers for firmware image generation and the memory

space required to store images before they are sent over-the-air for bootloading.

Figure 1: BlueNRG, BlueNRG-MS OTA master & slave devices

Note: For more information related to the BlueNRG and BlueNRG-MS kit platforms, refer to

the related user manuals available on ST BlueNRG web pages (see Section 6: "Related

documentation and references").

Table 1: "BlueNRG and BlueNRG-MS platform naming convention" describes the naming

convention used for referring to the BlueNRG and BlueNRG-MS platform LEDs and

buttons.

Table 1: BlueNRG and BlueNRG-MS platform naming convention

Resource name

BlueNRG, BlueNRG-MS

development platforms

BlueNRG, BlueNRG-MS USB

dongles

LED_D1

DL1 (yellow LED)

D2 (red LED)

LED_D2

DL2 (orange LED)

D3 (orange LED)

BUTTON_1

Push_Button

SW1

BUTTON_2

Joystick SEL

SW2