This repository is a collection point for a number of jump logging devices I designed for skydivers.
Three boards are part of the Tempo project: Tempo-BT, Tempo, and Peakick. All three explore modern sensor ICs for use in skydiving. The Peakick board is more research oriented. Peakick is design as a daughter board for experimentation with a range of microcontroller boards. It is most easily connected to SparkFun "Thing Plus" form factor boards, although it can be connected to almost any modern MCU/SOC board designed for 3.3V peripherals.
Tempo is a purpose built single board logger derived from Peakick. Essentially, it is a SAMD51 MCU dropped onto a Peakick board. This project includes PlatformIO-based firmware to drive this board as a stand-alone skydiving data logger. The firmware is operational and reliable and I use this board most often for my logging experiments.
This project was originally designed to experiment with real-time audible feedback at assist a skydiver in freefall. The original Peakick design stacks a SparkFun ESP32 Thing Plus atop a custom GNSS/sensor combo board. The SparkFun board supports an audio connection to Bluetooth earbuds or headphones. That work led me to design the Tempo-BT board.
- GPS/GNSS using a u-blox SAM-M10Q
- 6-DOF Inertial measurement / gyro using a ICM-42688-V
- Barometric pressure / temperature using a BPM390
- 3-DOF Compass/Magnetic measurement using a MMC5983MA
I am just getting started with this project, so all I'm doing for now is validating the sensor board designs and (soon) experimenting with basic BT audio capabilities.
| Folder | Description |
|---|---|
| hardware | KiCad PCB projects (using KiCad 7) |
| hardware/peakick | (original) u-blox GNSS + IMU + Barometric sensor PCB |
| hardware/tempo | (newer design) SAMD51 + u-blox GNSS + IMU + Barometric sensor PCB |
| hardware/tempo-bt | (newest design) u-blox NORA-B106 Bluetooth SOC (Nordic nRF5340) + u-blox GNSS + IMU + Barometric sensor PCB |
| enclosure | 3D-printable enclosures (Fusion360 format) |
| firmware | various Arduino sketches (mostly for historical reference) |
| platformio | Platformio test and operational projects for the Tempo board |
| platformio/tempo-logger | Skydiving logger firmware for the Tempo board - tested and reliable |
The enclosures are designed to be SLA printable. I print using a MakerBot Replicator 2 with Cura 5.3.1 as the slicer. Print resolution set to 0.15mm.
The PCBs are secured to the enclosure using M2.5 brass inserts and screws. The inserts are heat-inserted into the bottom shell using a soldering iron after printing.
All three boards were created using KiCad. In Peakick, in order to get the header alignment with the parent board as accurate as possible, I imported the SparkFun STM32 Thing Plus GitHub project to use its PCB layout.
I prefer 1 oz. Copper with ENIG finish. I ordered the Peakick V1 PCB from OSHPark and stencils from OSH as well. Tempo boards were ordered from PCBWay.
| QTY | MPN | Description |
|---|---|---|
| 1 | WRL-15663 | SparkFun ESP32 Thing Plus WROOM |
| 1 | N/A | peakick PCB assembly |
| 3 | 6 POS 5mm 0.10" receptacle (soldered to peakick PCB) | |
| 3 | 6 POS 0.10" headers | |
| 1 | 1578 | Adafruit 3.7V 500mAH LiPoly rechargeable battery |
| 3 | 1GNL7 | Grainger M2.5 Brass Inserts |
| 3 | M2.5 x 16 mm phillips screws | |
| 1 | N/A | Project enclosure (Top and bottom shells) |
The two boards are interconnected using 0.1" headers and receptacles. The header/receptacle parts were selected to minimize the gap between the two boards and still allow for quick interchange of each board when required. Nylon spacers are used with each of the mounting screws to minimize the effect of shock and vibration in the electrical interconnections.