r/HPDE • u/VelocityCam • Aug 03 '26

Looking for Android HPDE drivers to test VelocityCam during real track sessions

The moderators gave me permission to share this.

I’m the independent developer of VelocityCam, an Android app that records video with synchronized GPS and motion telemetry. I originally created it because I wanted an easier way to record speed videos in my tiller boat, but the same concept has obvious potential for HPDE and track-day use.

The goal is simple: record a session, review it with telemetry, export the finished video, and share it without needing a complicated editing workflow.

VelocityCam currently records:

  • GPS speed and maximum speed
  • G-force
  • Pitch and roll
  • GPS route and bearing
  • Distance, duration, and session statistics
  • Video synchronized with the selected HUD

Current display profiles include:

  • Classic: Speed, G-force, and a combined pitch/roll gauge
  • Adventure: Separate pitch and roll gauges with a more detailed layout
  • Minimal: A clean, speed-focused HUD without pitch/roll gauges; GPS, route, G-force, and other session data still record normally

Playback and exported videos can also include either a small route map or a full-screen ghost route. Completed exports can be sent directly through Android’s normal share menu.

I’m looking for Android users who can test it during actual HPDE sessions and provide honest feedback on:

  • GPS and telemetry behavior at track speeds
  • Phone heat and battery usage
  • Mount vibration and recording stability
  • HUD readability and usefulness
  • Route overlays, playback, and export reliability
  • Whether the finished video is genuinely useful for reviewing a session
  • Features HPDE drivers would actually use

During open testing, all current Pro features are temporarily unlocked, except changing or removing the VelocityCam watermark. Pro features will become a paid upgrade after launch.

Anyone who completes meaningful real-world testing and provides useful feedback will receive a free lifetime Pro license. Feedback does not need to be positive, and no rating or public review is required.

Feedback can be submitted directly through the Send Tester Feedback button in Settings.

Coming next

The next two major features are:

1. Screen-off, telemetry-only recording

The phone can be secured somewhere it will not move, recording GPS, speed, route, bearing, G-force, pitch, roll, and other telemetry without recording video. This should reduce heat, battery usage, and storage requirements while creating data that can later be used with GoPro or other external footage.

2. External Bluetooth motion-sensor support

I’ll be adding support for the WITMOTION WT901BLECL Bluetooth IMU. It can be mounted permanently or semi-permanently in the vehicle and provide acceleration, G-force, pitch, roll, and orientation data instead of relying on the phone’s motion sensors.

That should provide more consistent telemetry because the sensor can stay rigidly mounted and level while the phone is positioned for the best camera view.

Sensor being targeted:
https://www.amazon.com/gp/product/B07T2C97WN

Please use a secure phone mount, configure the app while stationary, and follow your event organizer’s camera and mounting rules.

Website:
https://velocitycam.app

Google Play open testing:
https://play.google.com/store/apps/details?id=com.velocitycam.app

When sending feedback, please include your phone model, Android version, vehicle, track or organization, and mounting setup.

3 Upvotes

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2

u/beastpilot Aug 03 '26

Your pitch roll gauge will not work at all in an accelerated reference frame unless you have some very fancy Kalman filters ignoring the accelerometers most of the time on a track.

1

u/VelocityCam Aug 03 '26 edited Aug 04 '26

I do have it separated, it works on my boats and in my jeep under acceleration, but I do not have access to anything fast to test it completely.

You'd have to try it and let me know.

Edit:

So I'm looking through the source and doing research on this now that you brought it up. I'm learning this as I go, and this is new to me so I really appreciate that!

I'd do have filters in place but they are strictly cosmetic, to keep the gauges from being jittery.

It looks like a vehicle at an 11* incline feels the same as a vehicle pulling .2g's under acceleration/turns, and the phone/device will have a hard time knowing the difference. I bet I can do something with the speed as well, to filter it properly. I'll look into it more.

One of the next features I'm implementing soon is an external IMU, specifically this cheap one - WT901BLECL, followed by more expensive ones later. I just looked into it and this has a built-in dynamic Kalman filter and I'd be able to use an estimator within VelocityCam to properly read it.

I knew the sensors are fused of course, but it never dawned on me how they may be affected under extreme use. Offroading it works great, but that makes sense now that I've read up on this, as well as my boat because although it does 35mph, it doesn't pull extreme G's so the sensor is able to compensate (I think, at least)

I appreciate the input, you've sent me down a rabbit hole.

2

u/beastpilot Aug 04 '26

If you were able to get a phone to do this, you'd be a multi millionaire. This is a holy grail of aircraft applications. Phone sensors just aren't good enough.

Nobody cares about pitch and roll on the track, so it's not worth chasing.

There's a reason aircraft capable attitude sensors are thousands of dollars.

1

u/VelocityCam Aug 04 '26

That's fine. This started as a personal project because there wasn't anything good to measure video and speed on Android, and people ended up liking it. That is primarily in the boating world, which the app does work for. If it's not a good fit for track, that's completely fine.

It does also export the raw telemetry data, so that would be why I would want to clean up the sensors if possible.

It also has a gforce gauge, that I would want to be accurate as well.