66 Channel LS20031 GPS 5Hz Receiver Quick Start Guide


LS20031 10Hz GPS Receiver

The LS20031 is a high performance, reliable, and inexpensive GPS module. It is the premier choice for most of our engineers, since it has a 5Hz update rate, a backup power source for quick locks (time to first fix), and a small form factor. The only downside is that it doesn't come with a connector. There is some minor assembly required, but it is very easy with the help of the LS20031 Assembly Guide.

Here are some good pieces of information to know about the LS20031, more details can be found in the datasheet:

  • There is a status LED that blinks when there is a fix. A fix means there are enough satellites in view to accurately calculate your position.
  • Configurable 10Hz update rate means you can get valid position, time, etc. data 10 times a second. Default setting is 1Hz.
  • The ceramic patch antenna is the large tan and white object soldered onto the green PCB. This must always point towards the sky.
  • The TX and RX pins are 3.3V TTL tolerant. This means you can directly connect this module to another 3.3V TTL device without the need of logic level conversion.
  • Commands can be sent to the module to configure settings. There is a handy program called Mini GPS that will help you configure your module. More information about configuration can be found here.

We also have a few other tutorials about GPS you might want to check out: GPS Buying Guide and GPS Tracking Comparisons.

Assembly

You might notice there is not a connector on the GPS, only bare pads. The first thing that needs to be done is to solder headers onto the bare pads, so you can connect the GPS to the system of your choice.

Here is the LS20031 GPS Assembly Guide.

Keep in mind, you will need the following tools and supplies:

 

Getting Started - Basic

Here is a quick and easy test is to check to see if the GPS is sending out valid NMEA data. Remember, the GPS antenna needs to be in clear view of the sky in order to receive valid NMEA data. It might work inside or next to a window, but I wouldn't rely on it!

Here is what you will need:

  • Assembled LS20031
  • FTDI Basic Breakout - 3.3V (RTL-09893)
  • M/F Jumper Wires (PRT-09140)

 

   

                                           LS20031 GPS                                                                 FTDI Basic - 3.3V

 

Now you need to connect the FTDI Basic to the LS20031 GPS. Here is a list of the required connections:

  • GPS Pin 5: No connection (or ground)
  • GPS Pin 4: to FTDI Basic ground (GND) pin
  • GPS Pin 3: to FTDI Basic pin RX
  • GPS Pin 2: No connection
  • GPS Pin 1: to FTDI Basic 3.3V pin

After you have the GPS and FTDI basic connected, plug the FTDI into a USB cable connected to your computer. Depending on your OS, you will need to install drivers for the FTDI Basic.

See the FTDI Basic Quick Start Guide for instructions on installing FTDI Drivers.

If the FTDI driver install was successful, the FTDI Basic should enumerate as a COM port. To check this in Windows: right click on 'My Computer', goto 'Properties' -> Hardware' -> 'Device Manager'. In the Device Manager under 'Ports (COM & LTP)', you should see 'USB Serial Port (COMxx)'.

Next, you need to open a serial terminal program. Most Windows machines have a program called hyperterminal already installed. You can use hyperterminal or any other alternative, FYI, there are many, i.e. TeraTerm, Minicom, etc. To find hyperterminal, goto the Start menu, 'Programs' -> 'Accesories' -> 'Communication' -> 'HyperTerminal'. Open the program and hit the 'properties' button.

  Make sure you select the same COM number as shown in device manager.

Also, click on the 'Configure' button and make sure 9600 baud rate is selected.

And finally, click the 'Call' button. (Note: if hyperterminal asks you to name your session, just name it whatever you like and move on). 

Once you hit the 'Call' button or open the terminal, you should see the TX LED on the FTDI Basic blink and you should see NMEA data streaming in the terminal window. If you are inside a building or if you GPS cannot get a lock, you will see something like this:

 

Once you have gotten this far, the next step is to learn how to connect your LS20031 GPS to an Arduino!

Comments 1 comment

  • I just looked at your NMEA data stream- and if you look at your $GPRMC line(sentences) you might notice that after the time 003544.226 (hhmmss.sss) your second part(status code) is V which means the data is Void (invalid). If it was an A that means it’s Active (The GPS could get a lock/fix). TinyGPS will have a fit if you don’t have an A for this sentences. Also, If TinyGPS does not parse your $GPRMC sentence correctly then you will never get the time or date (also in your $GPRMC sentences)- just thought I should point that out.