-blue){kind=icon}
Sensor server for Android with real-time 3D visualization, written in Delphi FireMonkey (FMX).
It reads the phone's accelerometer, magnetometer and gyroscope, broadcasts them over UDP as JSON to subscribed clients, and shows them in a 3D scene where the cube represents the phone and tilts with its real orientation (gravity always stays vertical).
It is a Delphi FMX port of the original SensorCast project written in B4A (Basic4Android), extended with gyroscope and 3D visualization.
- Accelerometer (
TYPE_ACCELEROMETER) — m/s² - Magnetometer (
TYPE_MAGNETIC_FIELD) — µT - Gyroscope (
TYPE_GYROSCOPE) — rad/s
Reading is by polling: the sensor callback stores the latest value under a lock and the UI reads it at its own pace. This avoids flooding the main thread.
- Listens on port 51042.
- A client subscribes by sending the text
HOLAtoPHONE_IP:51042. - Every 200 ms it sends each registered client a JSON to port 51043:
{
"accelerometer": { "x": 0.10, "y": 0.50, "z": 9.81 },
"magnetometer": { "x": -51.2, "y": -58.4, "z": 22.0 },
"gyroscope": { "x": 0.01, "y": -0.02, "z": 0.00 }
}- Wireframe cube = the phone, with X (red) / Y (green) / Z (blue) axes labeled in 3D.
- World frame: the cube tilts according to the phone's real orientation; gravity always points down (the smoothed accelerometer is used as the vertical reference).
- Sensor arrows: accelerometer (orange), magnetometer (magenta) and gyroscope (yellow ring perpendicular to the spin axis + axis arrow).
- Orbital camera: drag to rotate, wheel to zoom.
Sensors and timers are started in FormActivate and stopped in FormDeactivate so as not to drain battery in the background.
| File | Responsibility |
|---|---|
SensorCast.dpr / .dproj |
FMX project (Win64 for debugging + Android64) |
uMain.pas / .fmx |
UI, data panel, orchestration (timers, lifecycle) |
uSensorServer.pas |
UDP server + JSON serialization (Indy 10, no UI) |
uAndroidSensors.pas |
Sensor reading via JNI + local IP; simulated stub on desktop |
uScene3D.pas |
3D scene: cube, axes, arrows, world-frame tilt, camera |
Built with Delphi 12 Athens. Other versions will trigger the .dproj upgrade dialog on open.
- Open
SensorCast.dprojin RAD Studio. - Test on Windows: platform Win64, run. A stub generates simulated data, so the 3D view animates and the UDP server can be tested without a phone.
- Android: platform Android 64-bit, Debug configuration, connect the device (USB debugging) and run (F9).
Declared in the .dproj: INTERNET, ACCESS_NETWORK_STATE, ACCESS_WIFI_STATE. The accelerometer/magnetometer/gyroscope require no runtime permission.
$ip = "PHONE_IP" # the one shown by the app (wlan0 interface)
$udp = New-Object System.Net.Sockets.UdpClient
$udp.Connect($ip, 51042)
$hola = [Text.Encoding]::UTF8.GetBytes("HOLA")
$udp.Send($hola, $hola.Length) | Out-Null
$recv = New-Object System.Net.Sockets.UdpClient 51043
$ep = New-Object System.Net.IPEndPoint([Net.IPAddress]::Any, 0)
while ($true) { [Text.Encoding]::UTF8.GetString($recv.Receive([ref]$ep)) }See LICENSE.
Eduardo Balvís. Delphi FMX port of the B4A project SensorCast (UVigo / SCOA).