SparkFun RTK Reference Station Hookup Guide

Contributors: PaulZC

Modus Operandi

The following is a brief summary of the Reference Station's modes of operation. Please consult the RTK Product Manual for much more detail.

• BASE Mode
  • This is the default mode as it is the mode we think most users will want to use - but you always surprise us with the novel ways you use our products!
  • The Reference Station will perform a short 1-2 minute "survey-in" to establish the approximate position of the antenna (~1m accuracy).
  • It will then start generating RTCM correction data and - once configured - can send it to an NTRIP Caster over Ethernet.
  • The RTCM data will also be output as 3.3V Serial (UART) data on the ZED-F9P TX2 I/O screw connection on the rear panel. You can connect a Radio transceiver to that pin if desired.
  • You can establish the antenna position more accurately by collecting 'raw' satellite data for ~24 hours and post-processing it. You can find full instructions in the Product Manual.

• ROVER Mode
  • The Reference Station can of course also be used as a RTK Rover.
  • In Rover mode, the antenna position and other data is logged to microSD card.
  • RTCM correction data can be received over Ethernet from a NTRIP Caster - once configured - and used to achieve an accuracy of ~1.4cm under good conditions.
  • Use Rover mode to collect the 'raw' satellite data to establish your antenna's position accurately for Base mode.

• NTP Mode
  • The Reference Station can also act as a Network Time Protocol Server - servicing NTP requests over Ethernet.
  • The firmware defaults to using DHCP to obtain an IP Address. But you can also configure it to use a fixed IP Address and can define the DNS, Gateway and Subnet Mask too.
  • Because NTP is unique to the Reference Station, we talk about it a bit more in the next section.

• CONFIGURE VIA ETHERNET Mode
  • Abbreviated as "Cfg Eth", Configure-Via-Ethernet mode is a dedicated mode where the Reference Station can be configured via a web page over Ethernet.
  • This mode requires exclusive access to the WIZnet W5500 chip and the SPI bus and so the Reference Station actually reboots when this mode is selected.
  • When leaving this mode - either by exiting the web page or by pressing the Mode button - the Reference Station will reboot again into Base, Rover or NTP mode. The new mode is selected by the small drop-down box on the System tab.

• CONFIGURE VIA WIFI Mode
  • Abbreviated as "CfgWiFi", Configure-Via-WiFi mode is another dedicated mode where the Reference Station can be configured via a web page over WiFi.
  • By default, the Reference Station will appear as a WiFi Hot Spot / Access Point - but it can be configured to connect to your preferred WiFi network too.
  • The Reference Station will reboot when leaving this mode - to apply any changes made.

• ESP NOW Mode
  • Abbreviated as "E-Pair", ESP NOW is a way of linking two ESP32 processors via WiFi so that they can communicate with each other, line of sight up to approximately 250m
  • The ESP NOW link allows a base to share correction data with a single rover
  • More details are provided in the Product Manual