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date server GNSS(u-blox) 🗣️
2025-06 Pi 4Pi 5 LEA-M8TMAX-M8QNEO-7MNEO-6M discuss

M8T

The Huawei GNSS module has a LEA-M8T chip which supports GPS, Galileo, Beidou, and GLONASS. Due to having a Survey-In mode, this unit can attain a time fix with a single satellite. In practice, it means this GNSS module works great indoors and never loses its fix. It is highly recommended.

This module has no USB port, so connect it to a USB to TTL adapter for programming with u-blox u-center. Configure per the recommendations on the gnss page.

Huawei WD22UGRC pinout

pin 1 2 3 4 5 6 7 8
desc ANT 3V3/5V VCC/3V3 TXD NC RXD TP1/1PPS NC TP2 GND

This photo shows the pinouts on the board (click to enlarge):

Note that the TxD and RxD pins must be crossed. If the module isn't spewing data, verify that the pins are crossed. If the antenna supports it (all of mine do), connect 5V to pin 1.

pi 4 pi 5

Bill of Materials

Item Vendor(s) Cost
Huawei WD22UGRC GPS module eBay $25
SMA-F to SMB-F connector Amzn, AE $2
Active GPS Antenna, 30dB gain Amzn $11
2P-F to 1P-F 2mm to 2.54mm Jumper wires Amzn $8
Total $46

M8Q

Product: Waveshare MAX-M8Q GNSS hat

Configure the USB block jumpers to A mode and plug a USB cable into the HAT and a Windows computer with u-blox u-center installed. Configure per the recommendations on the gnss page.

Restore the jumpers to B mode (shown) and connect the hat to your Pi.

More docs are on the Waveshare wiki page.

Bill of Materials

Item Vendor(s) Cost
Waveshare MAX-M8Q GNSS hat AliExpress $30
Total $30

The link is for a kit which includes an antenna and the IPEX to SMA pigtail.

7M

As shown, getting the GNSS chip on a breakout board with a SMA connector makes it very easy to connect with an antenna. The breakout boards with pins connect easily to the GPIO on a Pi, the pins on a USB to TTL adapter, or a RS-232 serial to TTL adapter.

pi 4 front pi 4 back

Bill of Materials

Item Vendor(s) Cost
Bear GPS module 7M AliExpress $7
Active GPS Antenna, 30dB gain Amzn $11
5 Jumper wires AliExpress $2
Total $20

6M

1: Connect the NEO-6M to a USB to Serial TTL adapter and plug the USB port into a Windows computer with u-blox u-center installed. Configure per the recommendations on the gnss page.

As shown, getting the GNSS chip on a breakout board with a SMA connector makes it very easy to connect with an antenna. The breakout boards with pins connect easily to the GPIO on a Pi, the pins on a USB to TTL adapter, or a RS-232 serial to TTL adapter.

2: Connect the wires as shown.

pi 5 front pi 4 front pi 4 back

Bill of Materials

Item Vendor(s) Cost
Bear GPS module 6M AliExpress $6
Active GPS Antenna, 30dB gain Amzn $11
5 Jumper wires AliExpress $2
Total $19

References