NEO-M8T GNSS TIMING HAT
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Working with windows
1. Download and install u-centersoftware, then open the u-center
2. Set the jumpers in A area, connect GNSS antenna,Put the receiver of the antenna in an open area outside for receive GPS signal, Connect the Module to PC by Micro USB cable
3. Note that you need to set the side of the antenna without sticker upward, check the COM port in Device Manager. Use the u-center to connect MAX-M8Q by select the COM port and select auto baud rate.
4. Enable 3D mode and export the file by selecting File -> Database Export -> Google Map Html.
5. Download Text_Release software and unzip. Open the file by Chrome, then import the HTML file which we saved above to check the position.
6. For detailed information about the u-center software, please refer to User guide
Working with Raspberry Pi
Hardware connection
| PIN | Raspberry Pi(BCM) | Raspberry Pi(WiringPi) | Description |
| 5V | - | - | 5V Power input |
| GND | - | - | Ground |
| RXD | P14 | P15 | Receive pin of UART |
| TXD | P15 | P16 | Transmit pin of UART |
| SDA | P2 | P8 | SDA pin of I2C |
| SCL | P3 | P9 | SCL pin of I2C |
| PPS | P18 | P1 | PPS pin of Module |
| INT | P27 | P2 | Wakeup pin, low active |
Enable UART interface
Open a terminal and run the following commands
sudo raspi-config #Choose Interfacing Options -> Serial -> No -> Yes sudo reboot
Libraries installation
- Install Python libraries
sudo apt-get update sudo apt-get install gpsd gpsd-clients sudo pip3 install gps3
- Modify gpsd
#Open gpsd file sudo nano /etc/default/gpsd #Change the lines below and save USBAUTO="false" DEVICES="/dev/ttyS0" GPSD_OPTIONS="/dev/ttyUSB0"
- Donwload demo codes
mkdir ~/Documents/MAX-XXX_GNSS_HAT_Code cd ~/Documents/MAX-XXX_GNSS_HAT_Code/ wget https://www.waveshare.net/w/upload/0/0f/MAX-XXX_GNSS_HAT_Code.zip unzip MAX-XXX_GNSS_HAT_Code.zip
python Examples
Enter the folded rand run the following commands:
cd ~/Documents/MAX-XXX_GNSS_HAT_Code/RaspberryPi/python/coordinate_converter sudo python3 main.py
NTP Server
The system clock of drivers like personal compute or server always has calibration issues as the figure below. In high-frequency trading systems, this issue affects High-precision clock requirement applications like automated production lines, etc. The NEO-M8T's enhanced sensitivity and concurrent constellation reception extend coverage and integrity to challenging signal environments. It uses the atomic clocks of the satellite to get rid of the included network and other factors. Here we use NEO-M8T and Raspberry Pi to build an NTP server and provide a clock for the WLAN network indoor.
1. Connect the antenna to NEO-M8T GNSS TIMING HAT, and set the receiver close to windows.
2. Connect the NEO-M8T to Raspberry Pi, Power on, and wait for the PPS signal.
3. Open a terminal and run the following commands.
sudo apt-get install git cd ~/Documents sudo git clone https://github.com/beta-tester/RPi-GPS-PPS-StratumOne.git cd RPi-GPS-PPS-StratumOne sudo chmod 777 install-gps-pps.sh
4. Reboot Raspberry Pi after installing.
5. Open and modify /boot/config.txt file, change the gpiopin=4 to gpiopin=18 of the last line and save it.
sudo nano /boot/config.txt dtoverlay=pps-gpio,gpiopin=18,capture_clear # /dev/pps0
6. Test pps0 by the following command. And now the Raspberry Pi uses the time of NEO-M8T.
watch -n1 chronyc sourcestats -v
7. To provide time for other devices, you can access it by the IP address of Raspberry Pi like:192.168.6.93
8. You can check the time by the following command in a Linux device.
sudo apt install ntpdate sudo ntpdate 192.168.6.93
Working with STM32
Hardware connection
| PIN | XNUCLEO-F103RB | Description |
| 5V | - | 5V power input |
| GND | GND | Ground |
| RXD | P9(TX) | Receive pin of UART |
| TXD | P10(RX) | Transmit pin of UART |
HAL examples
- Download the demo codes
- Unzip and go into the directory of STM32 example
- Open the STM32 project by Keil software
- Compile and download the code to the XNUCLEO-F103RB board.
- Connect the UART2 of the XNUCLEO-F103RB board to PC and check the debug information by Serial Port Utility
Expected result
- 1. Cloudy day
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- 2. Rain day
Using with Jetson Nano
- Install Python library
sudo apt-get update sudo apt-get install python-serial sudo apt-get install gpsd gpsd-clients sudo pip3 install gps3
- Modify gpsd parameters
Open the gpsd file on the terminal
sudo nano /etc/default/gpsd
Modify the following parameters of the gpsd file, then save and exit the file.
USBAUTO="false" DEVICES="/dev/ttyTHS1" GPSD_OPTIONS="/dev/ttyUSB0"
+Download the demo
mkdir ~/Documents/MAX-XXX_GNSS_HAT_Code cd ~/Documents/MAX-XXX_GNSS_HAT_Code/ wget https://www.waveshare.com/w/upload/0/0f/MAX-XXX_GNSS_HAT_Code.zip unzip MAX-XXX_GNSS_HAT_Code.zip
- Check the port for data
sudo chmod 777 /dev/ttyTHS1 sudo minicom -D /dev/ttyTHS1 -b 9600 sudo cat /dev/ttyTHS1 sudo gpsd /dev/ttyTHS1 -F /var/run/gpsd.sock sudo cgps -s sudo killall gpsd sudo reboot
python
Enter the python directory and run the demo, and you can view the information directly on Google Maps
cd ~/Documents/MAX-XXX_GNSS_HAT_Code/RaspberryPi/python/coordinate_converter sudo python3 main.py
