Back

Point One Smart Antenna
on Windows

ntrip-example reads GGA from the antenna over a USB COM port, sends it to Point One, and forwards the RTCM corrections back to the antenna.

You need:

  • A Windows 10 or 11 PC with internet access

  • The Point One Smart Antenna 

  • Point One credentials (NTRIP username and password)

  • A clear view of the sky for testing

  1. Create a Free Point One account

You'll get a free six month extended trial of our highest accuracy service so you have plenty of time to get building. Sign up before starting the tutorials below.

Use the same email address you used to register for FUSE.

Get Your Point One Account

Get Your Point One Account

  1. Build the client

  • Install Visual Studio Build Tools and select the Desktop development with C++ workload.

  • Get the code. If you have Git for Windows, clone the repo; if not, use Code > Download ZIP on GitHub and extract it.

git

  • From the Start menu, open Developer Command Prompt for VS. Change to the repo folder and compile:

cd ntrip-example
cl /EHsc /std:c++17

When the build finishes, you'll have ntrip_client.exe in the folder.

3. Find the antenna's COM port

  • Plug in the antenna over USB.

  • Right-click Start and open Device Manager.

  • Expand Ports (COM) and write down the antenna's port, for example COM3.

To check you have the right one, unplug the antenna; the entry that disappears is the antenna. If you see no port, or a device with a yellow warning icon, install the USB-serial driver (see Troubleshooting). You can also list ports from PowerShell:

4. Edit config.json
Open config.json in the repo folder and fill in your values (replace COM3 with the proper value):
{
  "ntrip_host": "truertk.pointonenav.com",
  "ntrip_port": 2101,
  "ntrip_mountpoint": "AUTO",
  "ntrip_user": "<your NTRIP username>",
  "ntrip_password": "<your NTRIP password>",
  "serial_port": "COM3",
  "serial_baud": 115200,
  "tcp_port": 5000,
  "gga_interval_sec": 10


5. Run and verify
Run the client from the repo folder
If Windows Firewall asks about network access, click Allow. The client uses the network to reach the caster and to serve data on tcp_port.
Troubleshooting
Symptom
Fix
'cl' is not recognized
You're in a regular command prompt. Use Developer Command Prompt for VS instead.
Linker errors about WSAStartup or socket
You left out ws2_32.lib
"Access is denied" when opening the COM port
Another app has the port open.
No GGA, or garbled text
serial_baud doesn't match the antenna's baud rate (115200)
HTTP 401 from the caster / Unauthorized
Your username, password or mountpoint is wrong
Sample Smart Antenna output
Example GGA sentence
$GNGGA


Key
Value
Field
Meaning
$GNGGA
Sentence ID
GPS/GNSS fix data
212418.000 
Time (UTC)
21:24:18.000
3745.250501 N
Latitude
3745.250501 N → 37.45251°
12224.942773 W
Longitude
12224.942773 W → 122.24943°
5
Fix Quality
Fix Quality Codes: 0 = No Fix 1 = GPS/autonomous 2 = DGPS 4 = RTK Fixed 5 = RTK Float
21
Satellites
Satellites in use
0.83
HDOP
Horizontal precision indicator 
23.157 M
Geoid Separation
Height above sea-level (mean), in meters. 
1.0
Age of Corrections
Seconds since last RTCM correction
1056*51
Checksum
Integrity check, not data.