Use a GNSS Module to Add Navigation to Your Product

I remember when I bought my first car, and my parents bought me an aftermarket GPS unit for my birthday. The thing was bulky and attached to the windshield with a suction cup, and it was more of an eyesore than a frequently-used navigation unit. Today, these systems are much smaller and more accurate, thanks to greater integration at the board and component levels.

If you want to add accurate GPS navigation capabilities to your new product, a GNSS module gives you accurate positioning in a small package. Instead of using separate components to build a custom module and signal chain on your board, you can use a pre-packaged module to save on part count and board space. These modules incorporate the required antenna, amplifiers, signal conditioning components, and other components into a compact package.

What’s in a GNSS Module?

A GNSS module is designed to provide global positioning using multiple satellite constellations. Mobile products that will cross borders or are at risk of travelling outside GPS-accessible areas should use a GNSS module to access a different regional system (GLONASS, Galileo, BeiDou and/or QZSS).

A GNSS module is much like other system-on-modules (SoMs) in that it integrates multiple components into a small PCB. This can then be easily added to your main board through an edge connector, surface-mount connection, or coax connector. The idea is to prepackage all the required components needed for signal acquisition, amplification/filtering, and data output over positioning data over a standard interface (SPI, UART, etc.). Some GNSS modules include an integrated antenna, either as a printed patch antenna or ceramic chip antenna.

These modules also include integrated LNAs and filters to capture a GNSS signal from the antenna. The input may or may not be impedance matched, so make sure to check your data sheets. You’ll generally need to provide impedance matching, which will depend on the exact antenna being used to capture the signal. An additional RF amplifier in the signal chain should not be used as this will cause the input amplifier to saturate and produce strong intermodulation products.

Typical block diagram for a GNSS module.

Whether you use an integrated GNSS module or you build something custom, the output digital interface will provide position data over a standard protocol. UART and I2C are most common, but SPI is also available. Some modules can be easily integrated into a computer system over USB, allowing easy interfacing with a host application or a web application. Using a prepackaged GNSS module with integrated USB also makes application development easier before you build out a custom module.

GNSS Module Options

Instead of using separate components to build a custom GPS module for your new product, take a look at some of the GNSS module options below. These prepackaged GNSS modules can provide the same capabilities alongside other integrated features and with a smaller footprint.

The modules shown below do not include an integrated antenna and are bare-bones options for integration into a main board. The manufacturers shown below and other manufacturers offer modules under the same product line that include antennas or additional digital interfaces.

U-blox, NEO-M8P-2

The NEO-M8P-2 GNSS module from U-blox is one of the most common options for new IoT products. This GNSS receiver enables concurrent receiving and tracking on multiple GNSS systems. These receivers are configured for concurrent GPS and GLONASS reception by default, or a combination of BeiDou and GPS can be used. This surface-mount component is easy to place on a PCB and includes everything except an antenna and host MCU. Data is supplied over UART, SPI, an I2C compliant DCC interface, or over an integrated USB 2.0 PHY.

The U-blox NEO-M8P-2 GNSS module supports a rover operation mode between two different modules. A fixed module and rover module can communicate using a stream of RTCM 3 messages. Another configuration is to set-up the NEO-M8P-2 as a static or mobile base station. These modules also include integrated support for applications like geofencing and attitude sensing.

NEO-M8P-2 GNSS module block diagram. From the NEO-M8P-2 datasheet.

STMicroelectronics, TESEO-LIV3R

The TESEO-LIV3R from STMicroelectronics is a low-power surface-mount GNSS module with high sensitivity and multi-constellation support (GPS/Glonass/BeiDou/QZSS). This module has a smaller footprint than other GNSS products, although it doesn’t include an integrated antenna, matching networks, or power conditioning. However, it does include an integrated low-noise clock.

Positioning data is output from this component via I2C or UART. This module includes support for applications like geofencing, odometers, differential GPS, and IoT products. If integrated USB 2.0 communication is not needed, this GNSS module provides accurate positioning and navigation with lower cost and smaller footprint than the previous U-blox module.

TESEO LIV3R GNSS module from STMicroelectronics. From the TESEO LIV3R datasheet.

mikroElectronica, MIKROE-2670

If you’re looking for a prepackaged solution for development or production, the MIKROE-2670 GNSS module from mikroElectronica is a compact module that can act as a GPS tracking solution in concert with a host MCU. Positioning data can be captured from the module by the host MCU over a micro USB 2.0 cable, I2C, or UART. Simple add a GPS-compatible active antenna and a rechargeable battery, and package the module with an MCU board to create a complete GNSS solution.

Complete battery-powered GNSS module from mikroElectronica.

Other Components to Support GNSS Modules

The products shown above do not include an integrated antenna, although other modules are available that do include an integrated patch antenna or ceramic chip antenna. Any product with a GNSS module will need other components for full system operation. Here are some of the other components you’ll need for your positioning and navigation system:

• MCU, FPGA, or other PLD

• GPS/GNSS antennas

• Passives for matching networks

More products are including positioning and navigation capabilities, ranging from IoT products to robotics and autonomous vehicles. When you need to select a GNSS module for your product, try using the advanced search and filtration features in Octopart. When you use Octopart, you’ll have a complete solution for sourcing and supply chain management. Take a look at our integrated circuits page to start searching for the components you need.

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