01 · Challenge
City bus platforms publish arrival data in their own protocols. Stop signs had to register, take that data over a mobile link and show it clearly in two languages.
Case · Public transport · 4G + platform protocol
The bus platform talks.
The stop sign answers.
Smart bus-stop signs for city bus networks in East Asia. Each sign connects over 4G to the city's bus platform and shows when every route will arrive.
- Integration
- City bus platform protocol
- Link
- 4G, no cable to the stop
- Controllers
- C-Power 3 and 5 Series · custom firmware
- Layouts
- Single-row, three-row, double-sided
The sign, following the buses
Replica · sample routes · time runs 10×Within four minutes a route shows "arriving". Beyond an hour it shows the clock time instead of minutes. When the last bus has gone, the sign says so. Languages alternate automatically.
Reduced motion · manual controls
CITY HALL14:05
36CENTRAL STATION8 MIN
12SCIENCE PARKARRIVING
305AIRPORT15:20 ARR
36 CENTRAL STATION 8 MIN; 12 SCIENCE PARK ARRIVING; 305 AIRPORT 15:20 ARR
PAGE 1 / 2 · EN
UNDER 4 MIN
"Arriving" instead of minutes.
UP TO 60 MIN
Minutes until arrival.
OVER 60 MIN
The expected clock time.
LAST BUS GONE
Says so, instead of a stale estimate.
How the job was done
One firmware, each city's platform rules.
02 · Constraints
- No data cable to the stop: 4G only
- The platform protocol is fixed
- Data can arrive out of order or only once
- Different sign sizes per stop
- Readable at a glance, day and night
03 · Approach
- Custom firmware implements the platform protocol over 4G
- Route list and names configured per stop
- Arrival logic built from the platform's estimates
- Layouts chosen by sign size
- Route-based voice announcements on later versions
04 · Result
Signs register with the platform, show arrivals per route with clock and notices, and keep working as each city's platform rules change, through firmware updates rather than new hardware.
Signal path
From the bus platform to the passenger
03 · OURS · Controller
Registers with the platform, requests route information, keeps data that arrives out of order, works out what each line should say and reports status back on a schedule.
Project specification
- Controllers
- C-Power 3 and 5 Series, custom firmware
- Link
- 4G module on the controller
- Protocol
- The city bus platform's own protocol
- Layouts
- Single-row, three-row and double-sided signs
- Content
- Route, destination, arrival time, clock, notices, animations
- Languages
- Two, alternating
- Audio
- Route-based voice announcements (later versions)
- Schedule
- Timed screen on and off
Running a transit platform?
Send us your platform's interface document. We will tell you how a stop sign can register, what it can show and how it is updated.