TinkerRTK Adds Centimeter GPS Accuracy to Projects with Open Source Modules

GPS alone provides location data with an accuracy of one to three meters. This level might be fine for telling a human how to navigate on streets, but it is not acceptable for drones that need pinpoint accuracy. A process called RTK provides corrections that improve the accuracy to one centimeter. Offering an open sourced solution, Tinkerbug Robotics is launching a Crowd Supply campaign with a series of modules called TinkerRTK that can implement RTK base stations and rovers.

Real-Time Kinetics (RTK) applies corrections to Global Navigation Satellite System (GNSS) data from an external source. A network of non-mobile base stations provides a stream of RTCM formatted correction data to mobile receivers called rovers. This method offers up to one-centimeter accuracy, which is significantly more accurate than the typical couple of meters achieved with GPS alone.

TinkerRTK consists of several modules. TinkerNav is the base board with two microcontrollers and a GNSS SkyTraq PX1125R receiver. The two microcontrollers are an Espressif ESP32-C3 System on Chip (SoC) and a Raspberry Pi RP2040 microcontroller. The ESP32-C3 provides Wi-Fi and Bluetooth LE connectivity, while the RP2040 handles the radios and external interfaces. Several pins on the TinkerNav are available for connections to hardware via GPIO, SPI, I2C, and UART.

Connectivity modules called TinkerSend add a 4G cellular (SIM7000G) or LoRa (LLCC68) radio. This combination with the ESP32 on the TinkerNav means you have several choices for communicating correction data from a base station to a rover. Other modules include a board with a TFT Touchscreen and one called TinkerCharge. This add-on connects to a lithium-ion battery, which you can recharge using a solar panel.

Together, the TinkerRTK modules enable you to build a base station or use it with a rover. However, you are not required to make both. For example, a rover could use a public or private data stream, usually via subscription. If you build a base station, choosing locations that offer an exceptionally high signal-to-noise ratio is critical.

Tinkerbug Robotics plans to open source the designs. Today, you can find Arduino IDE code examples on their Github account and schematic images on the product pages. Visit the TinkerRTK on Crowd Supply if you're interested in buying pre-made modules. There, you can sign up for notifications when the campaign goes live.