Jun 03, 2026 · BLE
Dragy Dash: Making Dragy Pro Sensor Data Easier to Use
A quick iPhone and ESP32 project for getting Dragy Pro BLE telemetry out of a single-purpose timing workflow and into simpler live dashboards.
Source
Why I built it
Dragy Pro is good at its core job, but I was less interested in building another race-timing interface and more interested in getting at the sensor data in a simpler way.
This was a quick, fun project around a practical question: if the device already knows speed, distance, GNSS state, battery, and movement, what else becomes easier once that data is available outside the normal timing workflow?
The useful part is the interface around the sensor. On the phone, I wanted a compact dashboard. On the ESP32, I wanted a small display I could keep in front of me without making the setup feel heavy.
What is there now
- BLE discovery and connection handling for the Dragy Pro service shape.
- A write/notify path for the device handshake and live packets.
- UBX NAV-PVT decoding from the
FD02stream rather than treating the device like a black box. - An iPhone dashboard for speed, averages, GNSS state, distance, and lateral / longitudinal G.
- LilyGO ESP32 display pages for quick speed, average speed, timing, peak speed, distance, accuracy, satellite, altitude, and battery views.
Why it interests me
This is the sort of project I like because it sits between a few different things: mobile UI, embedded display constraints, BLE protocol work, and a physical device that has to behave in the real world.
It also has a useful 4x4 angle. Race timing is one use case, but the same sensor can support more ordinary questions: average speed over a track section, before/after comparisons after changing a vehicle setup, speed consistency over distance, or accelerometer-aware views for hard hits and rough sections. Some of that depends on how reliable the data is in practice, but that is exactly the kind of thing a small project like this makes easier to test.
Where I would take it next
The next useful step would be to make this less about one sensor and more about a small vehicle telemetry surface.
That could mean Bluetooth or Wi-Fi integrations for secondary power system state, an EcoFlow Delta, alternator charger current rate, Starlink status, and OBD2 readings alongside the Dragy data. I do not think the value is a bigger app for its own sake. The value is having one simple place to see the signals that matter when the vehicle is being used as a system.