SparkFun GPS-RTK Dead Reckoning ZED-F9R Hookup Guide

Contributors: bboyho, Elias The Sparkiest

Configure Your Pi

The Serial peripheral is not turned on by default. There are a few methods to adjust the settings. To enable it, you will need to do the following.

Raspberry Pi Configuration via Desktop GUI

Before we download the Python package, you will need to enable your serial UART port. There are a few methods of enabling the port but we recommend using the GUI: Raspberry Pi Start Menu > Interfaces > Raspberry Pi Configuration.

A window will pop up with different tabs to adjust settings. What we are interested is the Interfaces tab. Click on the tab and select Enable for Serial. If you would like to control the Raspberry Pi through the serial port terminal, you can select Enable for Serial Console. Since we are using the serial port to control another serial device, we will be selecting Disable At this point, you can enable additional interfaces depending on your project needs. Click on the OK button to save.

We recommend restarting your Pi to ensure that the changes to take effect. Click on the Pi Start Menu > Preferences > Shutdown. Since we just need to restart, click on the Restart button.

Shutdown	Turn Off, Restart, Log Off

raspi-config Tool via Terminal

If you prefer the old school method using a terminal, we can use raspi-config to enable it.

1. Run sudo raspi-config.
2. Use the down arrow to select 5 Interfacing Options
3. Arrow down to P6 Serial.
4. Select no if it asks about using the login shell to be accessible over serial.
5. Select yes when it asks you to enable hardware serial.
6. Select Ok to confirm.
7. Use the right arrow to select the <Finish> button.
8. Select yes when it asks to reboot.

The system will reboot. When it comes back up, log in and enter the following command

language:bash
ls /dev/ttyS0

or

language:bash
ls /dev/serial0

The Pi should respond with the port that was entered.

language:bash
/dev/ttyS0

or

language:bash
/dev/serial0

Note: If you are interested in testing the UART port with a serial loopback test, you can add a F/F jumper wire between Tx and Rx to echo characters back to the Pi using minicom. Just make sure to connect the pins when the Pi is powered down since the power pins are near the serial pins. First, install minicom using the following command in the terminal window. Make sure to agree to install and follow the prompts.

sudo apt-get install minicom

Once installed, type the following in the terminal to open minicom on the /dev/ttyS0 serial port.

sudo minicom -D /dev/ttyS0

With the jumper connected, any characters entered will loop back in the window. Sweet, we know that the serial port is working so you can remove the jumper at this point.

When finished, type CTRL+A followed by X to exit minicom.