Skip to content

Latest commit

 

History

History
20 lines (14 loc) · 2.02 KB

README.md

File metadata and controls

20 lines (14 loc) · 2.02 KB
Raw

Coin Firmware

This directory contains the firmware that creates a BLE peripheral loading the BLE bond and the SPACEKEY from flash using zephyr's settings API.

Usage

Please refer to the top level README file for flashing instructions. Especially, this firmware will not work properly when flashed onto a virgin, mass-erased chip, because the settings partition needs to be flashed too.

Flashing can be done using a BlackMagic Probe or using an STLinkV2 with OpenOCD.

Please note that you will not be able to lift the Access Port Protection with an STLinkV2. That means the coins are locked down from flashing until you get another flash tool. Don't worry - some STLinkV2 clones can be turned into BlackMagic Probes if they have sufficient (128K) flash. You could also buy a real BlackMagic Probe, an FT2232H breakout board or a SEGGER JLink. It is possible to remove the nRF52 Flash Protection with a Raspberry Pi.

When flashed, press the button on the coin to wake it up. The LED will light up and the coin will send BLE advertisements to the central signaling that it wants to connect. The LED starts flashing when the coin finds its central.

When finished authenticating, on connection loss or when a timeout of 10s is triggered, the coin goes into deep sleep mode.

Code Structure

The code is structured in 4 parts:

  • bas: contains ADC boilerplate code and GATT Battery Service
  • io: contains LED (blinking) and Button handling
  • spaceauth: registers settings handler for loading the SPACEKEY and the custom GATT Spaceauth Service that uses the BLAKE2s hash function to implement a challenge-response authentication
  • main: handles the connection and power management while (obviously) containing the main function