SparkFun
GNSS Flex pHAT with u-blox ZED-X20P
· MPN: GPS-29887
Bring high-precision GNSS to a Raspberry Pi with this GNSS Flex pHAT and u-blox ZED-X20P receiver module. It is built for centimetre-level positioning in dem...
Bring high-precision GNSS to a Raspberry Pi with this GNSS Flex pHAT and u-blox ZED-X20P receiver module. It is built for centimetre-level positioning in demanding navigation and control projects such as UAVs, guidance systems, auto-steering and high-speed robotics.
The pHAT connects to a Raspberry Pi through an extended 40-pin header and links to the included GNSS Flex module using standardised 2x10-pin headers, so the receiver module can be swapped for repair or future upgrades. It also includes USB-C data access, Qwiic, microSD, status LEDs and both SMA and U.FL antenna options.
An external GNSS antenna is required, along with a Raspberry Pi or similar single-board computer. By default, communication uses the Raspberry Pi primary serial bus: TX: GPIO14/Pin 8 and RX: GPIO15/Pin 9, although other interfaces can also be used.
According to u-blox, support for Precise Point Positioning (PPP) and full L-band correction services is still under development and will be made available through a future firmware update.
Features:
- Raspberry Pi Connectivity: Standard 40-pin GPIO header for a direct, secure connection.
- USB-C Port: Provides an alternative data interface to the GNSS module. (Read USB note)
- Versatile Antenna Connections: Equipped with both SMA and U.FL connectors to accommodate various antenna types.
- Mounting Hardware Included: Comes with the necessary standoffs, screws, and an extended header for a clean, stable setup.
- RTK & PPP Ready: Supports Real-time Kinematics (RTK), PPP-RTK, and Precise Point Positioning* for ultimate flexibility.
- L-Band Corrections: Natively supports L-band correction services*, eliminating the need for external receivers.
- High Update Rate: Ensures smooth and reliable operation in high-speed robotics and vehicle control systems.
- Uncompromising Security: Features multi-layered defenses including a Root of Trust, advanced jamming and spoofing detection, and Galileo OSNMA cryptographic authentication.
- ZED-X20P feature: Programmable flash memory
- ZED-X20P feature: Carrier phase output
- ZED-X20P feature: Jamming detection
- ZED-X20P feature: Galileo OSNMA
- ZED-X20P feature: Secure boot
Specifications:
- GNSS Flex pHAT connector: 40-pin socket for Raspberry Pi header
- GNSS Flex pHAT connector: 40-pin header for GNSS Flex modules
- GNSS Flex pHAT header: Two 2x20-pin, 2mm-pitch male headers
- GNSS Flex pHAT power: 3.3V
- GNSS Flex pHAT power: Backup power
- GNSS Flex pHAT power: USB bus detect (not a power source)
- GNSS Flex pHAT interface: USB data (Read USB note)
- GNSS Flex pHAT interface: UART (x4)
- GNSS Flex pHAT interface: SD card
- GNSS Flex pHAT interface: I2C bus
- GNSS Flex pHAT signal: PPS signal (x2)
- GNSS Flex pHAT indicators: LED indicators (x2)
- GNSS Flex pHAT indicators: Event indicators (x2)
- GNSS Flex pHAT connector: USB-C connector (Read USB note)
- GNSS Flex pHAT module connection: Interfaces directly w/ GNSS Flex Module
- GNSS Flex pHAT antenna bridge: U.FL connector
- GNSS Flex pHAT antenna bridge: SMA connector
- GNSS Flex pHAT storage: µSD card socket
- GNSS Flex pHAT connector: Qwiic connector
- GNSS Flex pHAT indicator LED: PWR (Red)
- GNSS Flex pHAT indicator LED: PPS (Yellow)
- GNSS Flex pHAT indicator LED: RTK (White)
- GNSS Flex pHAT indicator LED: PVT (Blue)
- GNSS Flex pHAT jumpers: Twenty-four jumpers
- GNSS Flex pHAT jumper function: Raspberry Pi GPIO isolation (x16)
- GNSS Flex pHAT jumper function: LED power isolation (x4)
- GNSS Flex pHAT jumper function: I2C pull-up resistors (x4)
- GNSS Flex Module: u-blox ZED-X20P Allband, GNSS module
- GNSS constellation: GPS (USA)
- GNSS constellation: Galileo (EU)
- GNSS constellation: BDS (China)
- GNSS constellation: QZSS (Japan)
- GNSS constellation: NavIC (India)
- SBAS system: WAAS (USA)
- SBAS system: EGNOS (EU)
- SBAS system: BDSBAS (China)
- SBAS system: MSAS (Japan)
- SBAS system: GAGAN (India)
- GNSS Flex Module header: Two 2x20-pin, 2mm-pitch female headers
- GNSS Flex Module connector: 40-pin socket for GNSS Flex pHAT / Breakout
- GNSS Flex Module power: 3.3V
- GNSS Flex Module power: Backup power
- GNSS Flex Module power: USB bus detect (not a power source)
- GNSS Flex Module interface: USB (x1) (Read USB note)
- GNSS Flex Module interface: UART (x2)
- GNSS Flex Module interface: I2C bus
- GNSS Flex Module signal: PPS signal (x1)
- GNSS Flex Module signal: PVT signal (x1)
- GNSS Flex Module signal: RTK signal (x1)
- GNSS Flex Module signal: Event signal (x1)
- GNSS Flex Module U.FL connector: GNSS Antenna (Active, Multi-band)
- GNSS Flex Module U.FL connector: 3.3V power for an active antenna
- GNSS Flex Module dimensions: 44.0mm x 34.0mm (Approx. 1.73" x 1.34")
- GNSS Flex Module mounting holes: Four mounting holes
- GNSS Flex Module mounting hole compatibility: 4-40 screw compatible
- GNSS Flex Module hole centres: 39.0mm x 29.0mm
- GNSS Flex Module header spacing: 36.0mm
- Flex Module interface USB: ZED-X20P USB (D+ and D-) (Read USB note)
- Flex Module interface I2C: ZED-X20P I2C (SDA and SCL)
- Flex Module interface Flex COM1: ZED-X20P UART1 (TX and RX only)
- Flex Module interface Flex COM2: ZED-X20P UART2 (TX and RX only)
- Flex Module interface Flex COM3: N/C
- Flex Module interface Flex COM4: N/C
- Flex Module interface PPS1: ZED-X20P TIMEPULSE
- Flex Module interface PPS2: N/C
- Flex Module interface EVENTA: ZED-X20P EXTINT
- Flex Module interface EVENTB: N/C
- Flex Module interface RTK LED: ZED-X20P RTK_STAT (Inverted)
- Flex Module interface PVT LED: ZED-X20P GEO_STAT (Geofence)
- ZED-X20P supply voltage: 2.7V to 3.6V
- ZED-X20P GNSS support GPS: L1C/A, L2C, L5
- ZED-X20P GNSS support Galileo: E1B/C, E5a, E6
- ZED-X20P GNSS support BeiDou: B1I, B1C, B2a, B3I
- ZED-X20P GNSS support QZSS: L1C/A, L1C/B*, L2C, L5, L6
- ZED-X20P GNSS support NavIC: L1*, L5
- ZED-X20P GNSS support SBAS: L1C/A
- ZED-X20P interface: USB (Read USB note)
- ZED-X20P interface: UART x2
- ZED-X20P interface: SPI
- ZED-X20P interface: I2C
- ZED-X20P service: AssistNow
- ZED-X20P service: PointPerfect
- ZED-X20P operating temperature: -40°C to 85°C
- ZED-X20P dimensions: 17.0mm x 22.0mm x 2.4mm
- Development note: *: Feature in development
Use a suitable active multi-band GNSS antenna and a short U.FL cable when bridging the module to the pHAT SMA connector for a sturdier antenna connection.
Jargon buster
Plain-language definitions for the technical terms used above.
- B1I
- A BeiDou satellite signal used for standard positioning. It matters because the receiver must support the signal bands used by a constellation to take advantage of those satellites.
- B2a
- A BeiDou satellite signal used by newer dual-band GNSS receivers. Support for B2a can improve accuracy and reliability when combined with other GNSS bands.
- BDS
- BeiDou, China’s satellite navigation system. Support for BDS gives the receiver access to more satellites, which can help maintain a better position fix in challenging locations.
- breakout
- A breakout is a small circuit board that makes a tiny or hard-to-solder component easier to connect to with standard pins. It matters because this OLED module can be wired into a microcontroller project without needing to solder directly to the display’s fine contacts.
- E5a
- A Galileo satellite signal band used for higher-performance positioning services. Support for E5a can help dual-band GNSS receivers improve accuracy and reduce errors from atmospheric delay.
- EGNOS
- Europe’s SBAS service for improving GNSS positioning accuracy and reliability. It is relevant if the receiver will be used in Europe or nearby supported areas without an RTK correction link.
- Flash memory
- Non-volatile memory that keeps stored data even when power is removed. In this sensor, it matters because enrolled fingerprint templates can remain saved after the project is turned off.
- GAGAN
- India’s SBAS service for improving GNSS positioning. It matters for projects in its coverage region because it can improve standard GNSS accuracy when RTK is not being used.
- Galileo
- Europe’s satellite navigation system. Galileo support can improve satellite availability and accuracy, especially when combined with GPS and other constellations.
- GNSS
- GNSS stands for Global Navigation Satellite System, covering positioning systems such as GPS and similar satellite networks. It matters here because high-precision GNSS modules can output lots of serial position data that this product can send wirelessly to a computer or phone.
- GPIO
- General-purpose input/output pins are microcontroller pins you can set in software to read signals, switch devices on and off, or connect to peripherals. The number of GPIO pins matters because it limits how many buttons, LEDs, sensors, and other parts you can wire directly to the board.
- GPS
- The US satellite navigation system used by GNSS receivers to calculate position and time. Support for GPS is important because it is widely available and often used together with other constellations for more reliable positioning.
- Headers
- Rows of metal pins used to plug a module into a breadboard or connect it with jumper wires. Pre-soldered headers make the module easier to use straight away without needing to solder the pins yourself.
- I2C
- I2C is a two-wire communication bus used by many sensors and small modules. It matters because several I2C devices can share the same two wires, but each device needs a compatible address and your controller must support I2C.
- L1C/A
- A GPS signal band used by many GNSS receivers for standard positioning. Support for this band helps determine which satellite signals the receiver can use and how well it can maintain a location fix.
- L2C
- A second GPS signal band used by dual-band GNSS receivers to improve precision and reduce errors caused by the atmosphere. It matters for RTK and high-accuracy applications because using two bands can produce faster and more reliable centimetre-level fixes.
- L5
- A modern GNSS signal band used by several satellite systems for more accurate and robust positioning. Dual-band receivers that include L5 can often perform better than single-band receivers, especially for RTK and areas with reflected signals.
- LED
- A light-emitting diode is a small electronic component that lights up when current flows through it in the correct direction. In this kit, LEDs create the flashing effect, so polarity and correct soldering matter for the project to work.
- MSAS
- Japan’s SBAS service for improving GNSS positioning. It is useful to know because SBAS benefits depend on whether your project is located in the service’s coverage area.
- pHAT
- A smaller add-on board format for Raspberry Pi, similar in idea to a HAT but usually not full-sized. It matters because pHAT compatibility can affect how neatly a board stacks or fits into a Raspberry Pi project.
- PVT
- Position, velocity and time data reported by a GNSS receiver. Knowing the PVT update rate helps you judge how often the board can provide basic navigation information to your project.
- Qwiic
- Qwiic is a plug-in connector system for I2C devices that uses small 4-pin cables, so you can connect compatible sensors without soldering. It matters because your controller or adapter also needs Qwiic, or you will need a cable or breakout to wire it up.
- QZSS
- Japan’s regional satellite navigation system designed to improve coverage around Japan and the Asia-Pacific region. QZSS support can improve satellite availability in supported regions when used alongside GPS.
- RTK
- Real-Time Kinematic positioning is a GNSS technique that uses correction data from a base station to greatly improve location accuracy. It matters if you need centimetre-level positioning for robotics, mapping, surveying, or tracking rather than ordinary metre-level GPS accuracy.
- SBAS
- Satellite-Based Augmentation System, a set of regional services that broadcast correction information for GNSS receivers. SBAS can improve ordinary GPS-style positioning, although it is not the same as centimetre-level RTK correction.
- single-board computer
- A complete computer built onto one circuit board, usually including the processor, memory, ports, and connectors. This matters because accessories like heatsinks must match the board’s layout and mounting holes to fit properly.
- SMA
- A threaded coaxial connector commonly used for antennas. It matters because you need antennas with matching SMA connectors, or suitable adapters, for the LTE and GNSS antenna ports.
- SPI
- A fast serial communication bus often used for displays, memory cards, and sensors. It matters because SPI devices need specific pins for clock and data, plus a separate chip-select line for each device.
- u.FL
- u.FL is a tiny snap-on antenna connector often used on compact wireless boards. A board with u.FL usually needs an external antenna, which matters if the product will be inside an enclosure or needs better antenna placement.
- UART
- UART is a simple serial connection that sends data over separate transmit and receive wires, often labelled TX and RX. It matters because this module is designed to replace a wired UART cable with a wireless link while keeping the same serial data format.
- USB-C
- A modern reversible USB connector used for power and data connections. On this product it matters because it can connect directly to a computer as well as to a microcontroller project.
- WAAS
- A North American SBAS service that provides correction data for GNSS receivers. It matters if you are using the product in a supported region and want better non-RTK positioning accuracy.
Find this product in
GNSS Flex pHAT Schematic
Schematic · 124.0 KB · Click any page to view full size
GNSS Flex pHAT Board Dimensions
Mechanical Drawings · 236.3 KB · Click any page to view full size
u-blox ZED-X20P Product Summary
Product Brief · 96.4 KB · Click any page to view full size
u-blox ZED-X20P Datasheet
Datasheet · 1.2 MB · Click any page to view full size
u-blox ZED-X20P Integration Manual
User Guide · 3.4 MB · Click any page to view full size
u-blox GNSS Product Overview
Product Brief · 545.1 KB · Click any page to view full size
u-blox X20 HPG Interface Description
User Guide · 3.0 MB · Click any page to view full size
u-blox HPG 2.02 Release Notes
Product Change Note · 150.2 KB · Click any page to view full size
Supplier page — sparkfun.com
Supplier Description · 1.1 MB · Click any page to view full size
GPS L5 Configuration Application Note
Document · 373.5 KB · Click any page to view full size
Resources & Downloads
Guides, code examples, and more
GNSS Flex pHAT KiCad Design Files
Schematic · ZIP · 672.7 KB
KiCad PCB and schematic project files for the GNSS Flex pHAT
GNSS Flex pHAT STEP Model
STEP File · STEP · 12.4 MB
3D STEP model of the GNSS Flex pHAT for enclosure design
u-blox ZED-X20P Firmware Binary
Firmware · BIN · 1.0 MB
Binary firmware image for the u-blox ZED-X20P module