What is DigiHUD Speedometer?
DigiHUD Speedometer is an Android app designed to show speed and distance information based on the location data received from your device’s GPS receiver. It’s an ongoing project and will continue to evolve over time.
The free version will continue to have bug fixes as required but will not receive any additional features.
Pro will continue to improve with additional features.
In the future it’s hoped to also have an iOS version available.
Why did you make it?
Back in early 2012 I saw a speedometer app running on a friend’s iPhone that worked really well and thought I’d have a go at writing a similar app for my Android phone. The app I saw had a green digital readout of our speed, as well as a few bits of other information. The display also flipped so it could be used as a Heads-up display in the car windscreen. Cool app I thought.
It was one of those “I’m sure I can do that” moments. It was my first dip into Android/Java development but I soon became hooked.
DigiHUD is still only a hobby which I work on in my spare time when I can.
Who is it for?
Currently only Android devices, including tablets (and hopefully smartwatches eventually), however I’m starting to look at iOS development with a view to one day porting DigiHUD to iPhone/iPad.
I want it to be available to as many devices as possible and will continue to try to support Android 2.3 and up.
Some features may not be available on some versions of Android depending on what parts of the framework are required.
How does it work?
The app ‘listens’ for location data coming from the GPS receiver, which in turn depends on getting enough signals from the GPS satellite array to ‘fix’ your location. This location data contains the current position (latitude and longitude), speed, heading, altitude etc. It then translates this data into your required unit (MPH/miles etc) and displays it using images.
That’s essentially all the app does and therefore is totally at the mercy of the quality and accuracy of the GPS data it receives. It doesn’t perform any fancy maths to try to reduce the lag that is always present when calculating speed as I’m not confident that this would work reliably or be of benefit to every device.
What information does it collect from my device?
By collect we’re talking about sending information to any system or device other than the device itself. No personally identifiable information is collected. The unique Android device ID is sent to differentiate one device’s usage from another.
Free: Anonymous usage information is collected to help improve the app and fix issues more quickly. The data is only sent when connected to a WiFi network, therefore doesn’t use the device’s cell data. There is an option within the app’s Settings to opt out of this service.
Pro: No usage data is collected.
How accurate is it?
It will only ever be as accurate as the data coming from the GPS receiver.
The better the GPS signal then the better the accuracy will be. The higher the sensor refresh rate the lower the lag will be (both the free and Pro versions have been tested and work perfectly with external high refresh rate GPS receivers).
When near buildings, under foliage or with an obscured view of the sky the accuracy will be reduced. Inside tunnels and buildings it’s very unlikely to get any usable signal at all. If you’re sat indoors don’t expect to see accurate data, the signal will be so weak the location will probably be jumping all around your location giving a false speed reading.
With a clear view of the sky and a high accuracy reading the app has been found to show within +/-1MPH of UK roadside Police speed signs on a Samsung Galaxy S3 in a windscreen holder.
Don’t think that because the speed doesn’t match the speed shown by your vehicles speedometer that the app is inaccurate; vehicle manufacturers usually design the speedometer to read high (to account for tyre wear and other environmental variables) so that if you’re travelling at the speed limit your actual speed is several percent slower.
Having said that, don’t rely on it for your speed if it’s accuracy is unknown (read this post).
A small snippet from The Car Expert about car speedometer accuracy (UK specific):
The UK law is based on the EU standard, with some minor changes. A speedo must never show less than the actual speed, and must never show more than 110% of actual speed + 6.25mph. So if your true speed is 40mph, your speedo could legally be reading up to 50.25mph but never less than 40mph. Or to put it another way, if your speedo is reading 50mph, you won’t be doing more than 50mph but it’s possible you might actually only be travelling at 40mph.
To ensure that they comply with the law and make sure that their speedometers are never showing less than true speed under any foreseeable circumstances, car manufacturers will normally deliberately calibrate their speedos to read ‘high’ by a certain amount. As your satnav is not the designated device by which a car’s speed is measured, it does not need to incorporate any fudge factoring.
If you’d rather show the speed matching your vehicle’s speed the Pro version allows a percentage offset to be applied to the speed.
Why is there a screen burn-in warning, and what is burn-in? Other apps I use don’t have this warning.
Screen burn-in can happen on some types of screen and can cause permanent damage when a still image is displayed for a long period of time.
The display can exhibit areas of discolouration or darkening.
After many many hours of testing the app over the last two years one of my devices (a Samsung Galaxy S3) does now show some burn-in, which can be seen as a slight yellowing of the display where the speed and other information is displayed in landscape mode. Another older device (an HTC Wildfire) has no burn-in at all. The Samsung has an AMOLED screen whereas the HTC has an IPS screen.
Because of this I thought it worth making people aware of the potential for damage when using any app that displays a still image for a long period of time.
Please check your device documentation for more information on whether your device may be susceptible.
What are the minimum device requirements?
Android 2.3. The device must have a built-in or external GPS receiver.
Can I use it when walking, cycling, jogging, or in an aircraft, boat, train or hot air balloon?
Yes, as long as your device can pick up a good GPS signal you can use it almost anywhere.
It will work from as slow as .75 up to 999 MPH/KPH/KTS. I have personally recorded a speed of 704 MPH on a flight from Miami to London.
Will it work in my pocket?
In testing it has worked just fine in pockets but it just relies on being able to pick up a good GPS signal.
Currently the main full-screen app won’t continue running when the screen is off or another app comes to the foreground. A future improvement is to allow the app to continue running in the background when not in focus. For now you should switch to Window mode before pocketing the device so that the app continues to run.
Update: Since the last update both the free and Pro versions of the app now run in the background. Use with caution though, Android can still kill the app in the background if it needs to reclaim memory.
Will the screen go off when I'm using it?
When in full-screen mode the display will be kept on by the app. In Window mode it depends on the app that it’s running on top of.
I have a high accuracy external GPS receiver. Will DigiHUD work with it?
Yes. I’ve had reports that the app works with external GPS receivers and I’ve recently bought a Garmin GLO Bluetooth Receiver to test DigiHUD’s support for these devices. From my own testing I’ve found that the app works perfectly at a refresh rate of up to 10 times per second.
How well it works will depend on factors like the speed of the device running the app and the speed of updates that Bluetooth can handle. I’ve found that even on an old HTC Wildfire S it keeps up with the GPS updates without issue.
The Pro version is currently being updated to indicate when external data is being used, or GPS data from the internal receiver.
I love adverts. Does it have adverts?
No. Sorry about that. Neither the Free or Pro versions have adverts, and never will. Ever.
Having said that, I reserve the right to promote other applications or tech that I think is relevant to DigiHUD within the app.
Will it work with Privacy Guard enabled, or other third-party privacy apps?
Privacy Guard, which is built in to some versions of Android, will stop DigiHUD working if it’s enabled for the app.
Other apps may also prevent it working if they block other app’s access to the device location.
Will you be adding more features in the future?
Not to the free version but it will continue to receive bug fixes as required.
There will be lots more features added to the Pro version in the future, as a way of thanking everyone who has supported me by buying it.
Unfortunately as this is a spare-time project features won’t be added very often.
Will it always be free?
The free version of DigiHUD will always be free.
I see there is a paid-for version. What extra features will I get?
Currently the following extra features are only available in the Pro version:
- Hide unlit number segments – make those empty digits disappear
- More Speed Warnings – have practically as many as you like. Set a colour, trigger speed, if there’s a continuous/single or no alert sound. Trigger on over-speed or under-speed
- Custom background colours – choose any colour you like for the background
- Custom sounds for speed warnings – choose a short audio file on your device for each speed warning if you wish
- Logging – Log your routes and export to .KML, .GPX and .CSV file formats, or open in Google Earth if you have it installed. Shows start and end addresses so needs Internet access permission
- Pins – want to save the current location for later? Just tap the Pin icon when travelling. From the Pins list you can open the pin in a map or navigate to it with your chosen installed navigation app
- Profiles – create individual Profiles for different vehicles, modes of transport, running, walking etc. Each Profile stores its own data and settings which allows them to be completely separate. Switch between them with a couple of taps
- Compatible with Samsung’s Multi-Window & LG’s Dual-Window Modes – You can split the screen 50/50 between DigiHUD Pro and other apps (like Maps)
- Day/Night mode – choose a different colour and brightness setting for day and night. There’s an Auto mode which automatically switches at sunrise and sunset
- Speed offset – adjust the displayed value up or down (up to +/-20%). Useful if you’d like the app to match the speed of your vehicle
- Greater precision – for common values like speed, average, maximum and trip
- Shows altitude
- ‘Litespeed’ – have the display switch to Lite mode when you go over a specified speed. When travelling at high speed the speed becomes the most important information when you need your eyes on the road
- ‘Speedtouch Lock’ – turn off all screen touch detections over a chosen speed
- Speed with Google Map view – splits the screen between speed and a live Google Map showing your location. If logging is enabled then a trail is displayed, but as this is still an experimental feature the trail will be lost when the mode is changed again
- More decimal places – Choose the number of decimal places to show for values
- Speed to tenths of a unit – The speed can be changed to show one decimal place
- Show Android Status and Action bars – A setting allows you to choose if you want to show the status bar or the status and action bars. You can of course leave it at the default; full screen. Be careful…if you have no Menu button you might not be able to access the app’s Menu!
- Turn off screen taps opening the Menu – There’s a setting to turn them off but they’re on by default
- Additional font – a slightly more rounded font has been added to the Pro version (hold the ‘A‘ icon for the popup)
- Edit values – Edit speed and distance values, like odometer, trip and max speed
- Auto power-on/off – Start/stop the app on power connected/disconnected. Only applies to the full-screen app, not window mode.
- Elapsed time this trip – Tap the clock to switch between the time and elapsed time. Can be set to count continuously or only when moving
- Simple compass – Tap compass for simple compass, bearing and odometer (tap again for classic compass)
- Hide Window mode title bar – Automatically fades out after a few seconds
- Set Window mode transparency – Make the background invisible so that only the speed is shown
- Turn off warning dialogs – stop warning dialogs appearing for example when GPS is turned off
Why has it put two icons in my app drawer?
The free version installs an icon for both full-screen and window modes.
After receiving feedback from Pro users the window mode icon was removed (in the Pro version) and replaced with the ability to create a shortcut directly to window mode if it’s required. In Android Lollipop a Widget will appear that can be added to a homescreen, which opens the app in Window mode.
My friend has an iPhone, will it ever be available for Apple devices?
My long term goal is to learn how to develop apps for Apple devices with the intention of porting DigiHUD to iOS.
How often is DigiHUD updated?
The Free version will only receive bug fixes as and when required.
Pro will continue to develop with new features and fixes. Updates aren’t very frequent and could be a couple of weeks to months apart.