README.md

SparkFun RTK Postcard

SparkFun RTK Postcard (GPS-26916)

Designed and manufactured in Boulder, CO USA, the SparkFun RTK Postcard is a compact development board for your high-precision positioning and navigation needs. This board combines the Quectel LG290P GNSS RTK receiver with an Espressif ESP32-PICO-MINI-02 MCU module, running our latest RTK Everywhere firmware. The ESP32 provides the SparkFun Postcard with WiFi and Bluetooth™ connectivity to operate as an NTRIP caster or client. Meanwhile, the 4-pin locking JST-GH connector allows users to transmit or receive RTCMv3 messages for RTK corrections from a local base station.

• The LG290P module is a quad-band, multi-constellation, high-precision, RTK GNSS receiver. The module can simultaneously receive signals from the L1, L2, L5, and L6/E6 frequency bands of the GPS, GLONASS, Galileo, BDS, QZSS, and NavIC GNSS constellations. In addition, the module supports SBAS augmentation systems (WASS, EGNOS, BDSBAS, MSAS, GAGAN, and SDCM), PPP services* (BDS PPP-B2b, QZSS CLAS, MADOCA-PPP, and Galileo HAS), RTCM, and RTK corrections for precision navigation with a fast convergence time and reliable performance. Connect with ease using a variety of interfaces, including UART, SPI*, and I2C*.

• The ESP32-PICO-MINI-02 is a powerful MCU module with WiFi, Bluetooth™, and BLE connectivity and comes integrated with 8MB SPI flash, 2MB SPI Pseudo static RAM (PSRAM), and a 40 MHz crystal oscillator. The ESP32 microcontroller itself features two CPU cores that can be individually controlled, with an adjustable clock frequency between 80 - 240MHz and a low-power co-processor for minor tasks, such as monitoring peripherals. It supports a range of peripherals including an SD card interface, capacitive touch sensors, ADC, DAC, Two-Wire Automotive Interface (TWAI), Ethernet, high-speed SPI, UART, I2S, I2C, etc.

With the RTK Everywhere firmware that comes pre-loaded, users can seamlessly operate the RTK Postcard as a base station or rover. These modes also offer additional functions, based on the available, wireless communication options:

• The RTK Postcard can transmit or receive RTCMv3 messages locally by connecting one of our SiK Telemetry radios.
• Through WiFi or Bluetooth™, the RTK Postcard can also function as an NTRIP caster or client.
• The RTK Postcard can transmit NMEA messages to a graphical information software (GIS) apps on any mobile device when paired as a Bluetooth™ device.

In addition to the RTK Postcard, we created the Portability Shield for the convenience of users. Simply connecting these products, provides a 1.3” OLED display and a five-way button to navigate the configuration settings and display PNT data; a microSD card slot for data logging; and a LiPo battery charger with a fuel gauge to take the RTK Postcard "on-the-go". All of these will operate plug-and-play without the need for new code.

Note

The RTK Everywhere firmware is open-source, so users can obtain, check, and even modify the device's functionality. This allows for easier feature expansion, bug maintenance, and longer device longevity.

Note

*: Feature is still under development

Important

• Currently, only the UART interface is supported by the LG290P module.
• Additionally, the corrections for some of the PPP services may not be implemented yet.

Documentation

• Hookup Guide (mkdocs) - The hookup guide for the SparkFun RTK Postcard hosted by GitHub pages.
  
• User Manual - RTK Everywhere Firmware - Documentation for the RTK Everywhere firmware
• SparkFun LG290P GNSS Arduino Library - An Arduino library for the LG290P GNSS module

Need to download or print our hookup guide?

• Print (Print to PDF) from Single-Page View

Repository Contents

• /docs - Online documentation files
  • assets - Assets files
    • 3d_model - Files for the 3D models
      • 3D CAD Model (.step)
    • board_files - Files for the product design
      • KiCad Design Files (.zip)
      • Schematic (.pdf)
      • Dimensions (.pdf)
    • component_documentation - Datasheets for hardware components
    • img/hookup_guide/ - Images for hookup guide documentation
• /Enclosure - CAD model for an enclosure
• /Hardware - Hardware design files (.brd, .sch)
  • /Production - Production files

Product Variants

• GPS-26916 - v1.0, Initial Release
• GPS-26620 - SparkFun Quadband GNSS RTK Breakout - LG290P (Qwiic) (w/o ESP32)

Version History

• v10 - Initial Release

License Information

This product is open source!

Please review the LICENSE.md file for license information.

If you have any questions or concerns about licensing, please contact technical support on our SparkFun forums.

Distributed as-is; no warranty is given.

• Your friends at SparkFun.