An experimental logger for skydivers
This is a stand-alone, battery-powered data logger designed to be carried by a skydiver during their jump. It includes a GPS, IMU, and altitude sensors. Data from all sensors is logged onto a Micro-SD card. The logged data can be reviewed post-jump by to-be-designed software.
The current sidekick design is composed of four off-the-shelf boards:
- Adafruit Feather M0 Adalogger - https://www.adafruit.com/product/2796
- Adafruit Ultimate GPS FeatherWing - https://www.adafruit.com/product/3133
- Adafruit MPU-6050 6-DoF Accel and Gyro Sensor - STEMMA QT Qwiic - https://www.adafruit.com/product/3886
- Adafruit DPS310 Precision Barometric Pressure / Altitude Sensor - STEMMA QT / Qwiic - https://www.adafruit.com/product/4494
- 2500 mAH LiPoly 3.7V rechargeable battery
- enclosure - Fusion 360 enclosure; designed to be 3D-printed
- src - Arduino-based firmware for the microcontroller
- images - supporting images and videos
Power: rechargeable 2500mAh Li-Polymer battery
Storage: removable microSD card
Log file format: one log file for each jump; raw log format is an extension of NMEA0183. Details to follow.
USB micro-B connector (for recharging and programming)
Bootloader programmed via a 10-pin J-Link compatible connector; routine Arduino programming via the USB connector.
The enclosure is designed to be 3D printed. Tolerances between the upper enclosure, lower enclosure, and the PCB are quite tight - printing precision will be important. Since 3D printing technologies will vary in their precision, you may need to scale or otherwise modify the objects to adequately match the final measurements in the original design.
For example, I printed the prototype enclosure on a MakerBot Replicator 2 (PLA) printer. Using the default print settings I know that an object will shrink typically by about 1% post-printing. I set the scale to 101% to compensate for that in the MakerBot Desktop tooling and the end result works well.
This PCB design uses several Adafruit Feather and Stemma QT sensor boards. Adafruit maintains a family of excellent microcontroller and sensor evalation boards and companion software. Support them. They deserve it.
The enclosure for this project was designed using the personal edition of Fusion 360. Autodesk supports the Maker community through access to this epic design tool. Try it out.
THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.