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Personal project

HUD Map

Directions in plain sight.

HUD Map sends each turn from the iPhone to the car’s built-in head-up display.

iPhone · CarPlay · Apple Watch

A drawing from the driver’s seat at dusk: a left-turn arrow and 0.8 mi float on the windshield above the dashboard, and the car’s screen shows HUD Map in CarPlay with the same turn.

Under the hood.

HUD Map is really a connector. Each turn leaves the iPhone as a one-line message, crosses the adapter’s Wi-Fi next to wireless CarPlay, and reaches the car as an iAP2 route guidance update, the kind an iPhone sends over a cable. Nothing in the car is modified.

A drawing of how a turn travels: 1, HUD Map on the iPhone sends the next turn over CarPlay’s wireless connection; 2, the CarPlay adapter passes it through its cable into the car; 3, the car’s own head-up display shows the turn on the windshield.

  1. HUD Map

    iPhone

    MapKit plans the routes. HUD Map’s guidance system tracks where you are on the route, picks the next turn and reroutes if you miss one. The guidance system sends the turn and its distance in meters to the adapter over TCP.

  2. A relay added to its software

    CarPlay adapter

    It still runs wireless CarPlay, standing in for a plugged-in iPhone. The relay starts when the adapter powers on, listens for HUD Map on its Wi-Fi and turns HUD Map’s lines into route guidance updates for the car.

  3. Its own head-up display

    The car

    The car converts the meters to miles and draws the turn on the windshield.

TCP
over the adapter’s Wi-Fi, next to wireless CarPlay
Up to 2
updates a second near a turn, and a heartbeat every 2 seconds
1,494
lines from real drives replayed against the relay on the bench

Heads up.

HUD Map does its own turn-by-turn navigation on iPhone, CarPlay and Apple Watch.

  1. Directions say when a turn comes at a light or a stop sign.

  2. The next turn on your wrist, with a tap before each turn.

  3. See how routes compare.

  4. The next turn and the arrival time on the Lock Screen and in the Dynamic Island.

HUD Map on iPhone during a drive: in 0.8 mi, at the traffic light, turn left onto Elmwood Ave, with the light marked on the map. Arrival is at 12:51 PM, 22 min and 10 mi away.
HUD Map on Apple Watch Ultra: in 0.8 mi, at the traffic light, turn left onto Elmwood Ave, then US-21 S.Three routes to Riverbanks Zoo & Garden: 7 min via Taylor St, the fastest; 8 min via Gervais St, 1 min slower; and 7 min via I-126 W, about the same time. A Go button is below.The iPhone Lock Screen at 12:30 on Friday, October 16, with HUD Map’s next turn in 0.2 mi onto Elmwood Ave, and Riverbanks Zoo at 12:50 PM, 21 min away.

Also in HUD Map

Turns on the glass

The next turn shows on the head-up display.

Reroutes

Spots a wrong turn and picks a new route that heads the way you’re going.

Keeps up with traffic

The time left follows the traffic, and HUD Map offers a faster route when one opens up.

Find Nearby

Gas, food, coffee, parking and EV chargers close by.

Skip the typing

Search finds your contacts’ addresses, upcoming events with a place show up before they start, and an address you copy is ready to open.

CarPlay

The full app runs on the car’s screen and on the CarPlay Dashboard, with Home and Work one tap away.

A screen for the passenger

A second screen on the iPhone for adding a stop or switching routes while CarPlay keeps guiding.

The arrival

When you’ll get there and how far is left. Double tap to end.

3D map

Buildings and hills in 3D, and an arrow that glides along the road between updates.

A personal project.

Why it was built

CarPlay handles almost everything in the car, but the head-up display only shows directions from the car’s own navigation. That system’s 3G connection is no longer supported, and getting an address from a phone into it is tedious.

Apple Maps doesn’t send its turns to the head-up display, and it doesn’t share them with other apps. So HUD Map is a connector that gets each turn from the iPhone, through the adapter, to the car. That meant building the navigation too.

Why it won’t be released

Releasing it would mean modifying a CarPlay adapter for every car it runs in.

Personal project

HUD Map

Status
Personal project
Works with
iPhone with iOS 27
CarPlay
Approved by Apple
Apple Watch
Yes
Developer
NUTTR