Flight Sensor Firmware/Software Repository

• common: Shared common source used by multiple projects
• flight-recorder: Python tool to interface to the flight sensor firmware over BLE
• libs: external dependencies used by the build
• nRF5_SDK: Nordic SDK 17.3
• projects: All firmware applications
  • flash-dev: project used by flash debugging/development
  • flight-sensor: main firmware application for stream and recording flight data

Project Overview

This project is intended to be used as data collection and analysis platform for measuring the orientation of disc golf discs. A sensor node with a processor and an inertial measurment unit (IMU) is attached to a disc. During flight, the node records IMU data to local memory. After the disc is recovered, the flight data is retreived via Bluetooth using the flight-recorder python tool. After data is collected, the flight-analysis python tool is used to process, analyze, plot, and animate flight data.

Sensor Node

The sensor node contains the following components:

• Nordic nrf52840: Bluetooth SoC build around ARM Cortex-M4 processor
• Invensense ICM20948: 9-axis inertial measurement unit with on-chip Cortex-M0 digital motion processor for sensor fusion
• Macronix MX25R6435F: 64 Mbit Serial NOR Flash with QSPI

Flight Recorder

To communicate with the sensor node via Bluetooth, the flight-recorder tool uses the blatann python library, a high level interface for performing bluetooth operations via Nordic's pc-ble-driver-py and connectivity firmware running on a PCA10056 evaluation board. The flight-recorder tool uses the imu-service command set consisting of the following operations:

• stream: enables IMU and starts transmitting raw IMU data via BLE notifications
• record: enables IMU and starts saving raw IMU data to flash
• playback: retrieves IMU data from flash and transmits via BLE notifications
• calibrate: starts calibrations of IMU

Build Instructions

Downloads

• GNU ARM Embedded Toolchain here (Version: v10.3.1 10 2021)
• Segger J-Link Drivers here (Version V7.58b)
• Nordic Command Line Tools here
• Visual Studio Code here

Installs

GNU ARM Embedded Toolchain

• Verify that correct installer version is downloaded
• Run the installer using default options
• Ensure that the install path is here: C:\Program Files (x86)\GNU Arm Embedded Toolchain\10 2021.10

Segger J-Link Drivers

• Run the installer using default options

Nordic Command Line Tools

• Run the installer using default options

Visual Studio Code

• Run the installer using default options

Make

• A copy of the make execute is located in /libs. Copy this to your local directory and add to path.
• Run make --version to verify that it has been correctly added to your path.

Fimware Build Instructions

Building

1. Navigate to a project. Example: projects/flight-sensor
2. Run make setup to install necessary python packages
3. Run make to build the firmware
4. For Softdevice projects, run make flash_softdevice to program the softdevice
5. Run make flash to program the firmware application

Config Editor

1. Run make sdk_config to run the config editor

VSCode Setup Instructions

C/C++ Properties

1. Open the root directory in VS Code
2. Select the Extensions view icon on the Activity bar
3. Search for and install C/C++
4. Open the command palette (CTRL+SHIFT+P) and run >C/C++: Edit Configurations (JSON) to generate a c_cpp_properties.json file.
5. Update .vscode/c_cpp_properties.json to have the following settings:
   • "compilerPath": "C:/Program Files (x86)/GNU Arm Embedded Toolchain/10 2021.10/bin/arm-none-eabi-gcc.exe"
   • "cStandard": "c11"
   • "cppStandard": "c++17"
   • "intelliSenseMode": "gcc-arm"
6. Navigate to a project and run make vscode. This will update the c_cpp_properties.json file with the correct include paths and defines for the project

Logging

1. Under C:\Program Files (x86)\SEGGER\JLink, run JLinkRTTViewer.exe
2. The log viewer can be buggy, use F3 to disconnect and F2 to connect after programming the device

Debugger

1. Select the Extensions view icon on the Activity bar
2. Search for and install C/C++
3. Under the .vscode directory create a file, launch.json
4. Update the file with the following text:

{
    "version": "0.2.0",
    "configurations": [
      {
      "name": "debug",
      "type": "cortex-debug",
      "request": "launch",
      "cwd": "${workspaceRoot}",
      "executable": "${workspaceRoot}/projects/flight-sensor/_build/nrf52840_xxaa.out",
      "serverpath": "C:/Program Files (x86)/SEGGER/JLink/JlinkGDBServerCL.exe",
      "armToolchainPath": "C:/Program Files (x86)/GNU Arm Embedded Toolchain/10 2021.10/bin",
      "servertype": "jlink",
      "device": "nrf52840_xxaa",
      "interface": "swd",
      "serialNumber": "", //If you have more than one J-Link probe, add the serial number here.
      "jlinkscript":"",
      "svdFile": ""
      }
      ]
}

5. In the Run tab, select Start Debugging or press F5