Getting Started

Raspberry Pi Setup

1. Enable UART and I2C

   Open Raspberry Pi configuration and enable the serial port and I2C interface:

   sudo raspi-config
   # Interface Options → Serial Port → Yes
   # Interface Options → I2C → Yes

2. Connect the HAT

   • Mount the LC29H HAT onto the Pi’s 40-pin GPIO header
   • Set the yellow jumper to position B (UART mode)
   • Connect the L1/L5 antenna to the IPEX socket
   • Place the antenna with clear sky visibility

3. Verify the serial port

   Pi 4B

   ls -la /dev/ttyS0
   # Should show the serial device

   Pi 5

   ls -la /dev/ttyAMA0
   # Pi 5 uses a different UART device path

4. Install the lc29h CLI

   # Install via uv (recommended)
   uv tool install lc29h
   
   # Or use pipx
   pipx install lc29h

5. Get your first fix

   lc29h --port /dev/ttyS0 monitor

   You should see NMEA sentences streaming within seconds. A full 3D position fix typically takes 26 seconds from cold start (under open sky), or as fast as 1 second for a hot start.

First Position Fix

Once the module powers up with antenna connected, it begins searching for satellites automatically. Watch the PPS LED — when it starts blinking once per second, you have a fix.

# Check module info and firmware version
lc29h --port /dev/ttyS0 info

# Stream position data
lc29h --port /dev/ttyS0 monitor

Example output:

Fix: 3D | Lat: 22.54114 N | Lon: 114.07791 E | Alt: 42.3m
Satellites: 18 | HDOP: 0.7 | Speed: 0.00 kn | Course: 125.29°

Tip

If the module doesn’t acquire a fix within 2 minutes, verify:

• Antenna is connected firmly to the IPEX socket
• Antenna has clear sky view (not indoors or under metal roofing)
• Module label faces downward (toward ground) with antenna facing sky

Alternative: gpsd

For applications that use gpsd, install and configure it:

sudo apt-get update
sudo apt-get install gpsd gpsd-clients

Edit /etc/default/gpsd:

USBAUTO="false"
DEVICES="/dev/ttyS0"
GPSD_OPTIONS="-n"

Restart the daemon and test:

sudo systemctl restart gpsd
gpsmon

What’s Next?

Depending on your variant and use case:

• LC29H(AA) → AGNSS Fast Fix to reduce cold start to 5 seconds
• LC29H(DA) → RTK Rover Setup for centimeter positioning
• LC29H(BA/CA) → Dead Reckoning for tunnel/canyon navigation
• LC29H(BS) → RTK Base Station to set up your own reference station
• Any variant → Python CLI Guide for full command reference

FAQ

No GPS signal indoors?

GNSS signals are too weak to penetrate buildings reliably. Connect the antenna to the IPEX socket and position it with clear sky view. Allow approximately 1 minute for initial acquisition; base station survey-in requires extended observation time.

RTKBase deployment on Raspberry Pi?

The Stefal RTKBase project provides a web-based interface for LC29H(BS) base station operation on Raspberry Pi. See the RTK Base Station guide for setup instructions.