Map Widget

✦ Special

The Map widget renders an interactive map and places a marker at the latitude/longitude reported by the device. Ideal for vehicle tracking, drone telemetry, asset monitoring, and mobile devices.

Default size: 3 × 3 grid cells

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Configuration

Property	Type	Default	Description
mapType	street | satellite | hybrid	street	Map tile style
showTrail	boolean	false	Draw a polyline of recent positions
trailLength	number	50	Number of trail points to show
Device	device	—	The device to read from
Pin	V0–V255	—	The virtual pin for GPS data
Label	string	—	Widget label

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Sending GPS from firmware

The Map widget expects a comma-separated string "lat,lng" or a JSON object:

String format (simplest)

#include <TinyGPS++.h>

void loop() {
  Vwire.run();

  while (gpsSerial.available())
    gps.encode(gpsSerial.read());

  if (gps.location.isUpdated()) {
    char buf[32];
    snprintf(buf, sizeof(buf), "%.6f,%.6f",
             gps.location.lat(), gps.location.lng());
    Vwire.virtualSend(V0, buf);  // "48.858844,2.294351"
  }
}

JSON format (with extra fields)

char buf[128];
snprintf(buf, sizeof(buf),
  "{\"lat\":%.6f,\"lng\":%.6f,\"speed\":%.1f,\"alt\":%.1f}",
  lat, lng, speedKmh, altMeters);
Vwire.virtualSend(V0, buf);

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Trail mode

Enable showTrail to draw a line connecting the device's last N positions. Useful for:

• Visualizing a delivery route
• Reviewing a flight path
• Checking if a vehicle deviated from expected path

Trail points come from the time-series DB — historical positions are shown even after a page reload.

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Tips

Update rate

GPS fixes typically update once per second. Updating VWire at ~1–5 second intervals is sufficient and conserves bandwidth and battery.

Accuracy

Consumer GPS modules have ±3–10 m accuracy. Use the marker for general tracking only; do not rely on pixel-perfect positioning.