The Sub-$100 TinkerNav Puts Centimeter-Level GNSS RTK Positioning in the Palm of Your Hand

New Jersey-based electronics startup Tinkerbug Robotics has launched an open source gadget designed to deliver Global Navigation Satellite System (GNSS) positioning with real-time kinematics (RTK) in a compact footprint: the TinkerNav.

"You can now incorporate one-centimeter-level accuracy into your next project using Real Time Kinetic (RTK) GPS for less than ever before," the company says of its board. "Advances in GPS receivers, RTK algorithms, and microprocessors allows us to offer fully open source solutions that are easy to use in your projects or run as standalone devices on a reasonable budget."

The TinkerNav itself is based on an Espressif ESP32-S3 connected to a SkyTraq PX1105R GNSS receiver, a part Tinkerbug chose specifically owing to a strong bang-for-your-buck performance/price ratio against the more popular u-blox ZED-F9P. "The u-blox ZED-F9P covers the L1 and L2 bands while the PX1105R covers the L1 and L5 bands, with similar numbers of satellites [receivable]," the company explains. "[Both] receivers have comparable RTK accuracy, update rates, and cold start/RTK convergence times."

RTK, for those unfamiliar, is a correction system which dramatically boosts the precision available from GNSS constellations like GPS: an RTK-capable GNSS receiver locks on to the satellites and calculates its position as standard, but can also receive correction data from a fixed-position base station — bringing, in ideal conditions, centimeter-level accuracy.

"You can use the [Espressif] ESP32-S3 to send or receive RTK correction data to or from an internet source with a Wi-Fi or BlueTooth connection," Tinkerbug says of the board's capabilities. "The ESP32-S3 can also connect to another TinkerNav using Wi-Fi or a direct connection to send or receive correction data. If additional range is needed, or the base station and rover are not connected to Wi-Fi, use the the TinkerSend LoRa radio [add-on]."

Hardware design files and software sources are available on GitHub under an unspecified license; assembled TinkerNav boards are available on Tindie at $99, with the TinkerSend LoRa radio add-on priced at $29.