Q: What would be more accurate, my vehicles speedometer or a GPS I have on my dashboard? A: They both can be accurate and inaccurate. Speedometer: Aftermarket modifications, such as different tire ...

The display itself is a gutted marine speedometer fitted with the movement ... [Grant] stuffed an ATTiny85 with a GPS module into the gauge and cooked up a script to convert the GPS velocity ...

Built for simplicity, elegance, and extreme practicality, Speed is a GPS speedometer that uses the iPad’s location data to tell you how fast you’re traveling. It works with iPads that have GPS ...