simpleRTK2Blite hookup guide

Hardware overview:

You can use simpleRTK2Blite as:
  • A standalone board, connected to a Pixhawk autopilot, to an XBEE socket, or using the included XBee-to-USB adapter
  • A “Moving Base”, connected to top of the classic simpleRTK2B. In this configuration, the classic simpleRTK2B gives you position + accurate GPS heading.
  • You can upgrade your LR/MR rovers, to provide RTK position + accurate GPS heading by connecting simpleRTK2Blite between simpleRTK2B and the MR/LR radio.
The main component of simpleRTK2Blite is u-blox ZED-F9P. If you are an advanced u-blox GPS user, you might want to have a look at the very extensive u-blox documentation: https://www.u-blox.com/en/product/zed-f9p-module#tab-documentation-resources

Power:

The simpleRTK2Blite board can be powered from 3 different sources:

  • Pixhawk connector (5V)
  • USB connector from the included XBee-to-USB adapter (5V)

  • XBee header (3.3V)

Only 1 of them is needed to use the board, but you can also connect the 3 at the same time, there’s no risk.

Communication ports:

simpleRTK2Blite board has a few interfaces that we will now explain in detail

BOTTOM XBee header

You can use this header to connect an to any XBee compatible socket. The following pins are available:

  • VCC, which is an input for 3.3V
  • XBee UART RX, at 3.3V level
  • XBee UART TX, at 3.3V level
  • GND

This interface is connected to ZED-F9P UART1.

XBee-to-USB adapter

This mini-USB board connector gives you access to the UART1 of ZED-F9P, via an FTDI USB-to-UART converter.
We find very practical to configure the u-blox ZED-F9P with this connector and the u-center Windows tool.

 

If your PC doesn’t recognize the device, you will need the VCP driver from FTDI: https://www.ftdichip.com/ftdichip/Drivers/VCP.htm

Pixhawk connector

This connector is a standard JST GH that can be used to connect the simpleRTK2Blite to a Pixhawk autopilot. You can also use this connector to power the board.

The Pixhawk JST-GH connector is following the Pixhawk standard:

  • 1: 5V_IN
  • 2: ZED-F9P UART1 RX (3.3V level)
  • 3: ZED-F9P UART1 TX (3.3V level)
  • 4,5: Not connected
  • 6: GND

Please note that the board only includes GPS and doesn’t include magnetometer.

TOP XBee socket

You can use this socket to connect an XBee compatible radio. The following pins are available:

  • VCC, which is a 3.3V output with maximum current 250mA.
  • XBee UART RX, at 3.3V level
  • XBee UART TX, at 3.3V level
  • GND
This interface is connected to ZED-F9P UART2.
Special function pins

In addition to above, there’s also a few additional pins available for the most advanced users:

  • Safeboot
  • Reset_N
To learn more about this pins, we recommend you to read ZED-F9P documentation, available here: https://www.u-blox.com/en/product/zed-f9p-module#tab-documentation-resources

Antennas

GPS/GNSS Antenna

simpleRTK2Blite requires a good quality GPS/GNSS dual band antenna. The board is compatible with both active antennas supporting 3.3V supply and passive antennas. The maximum output current is 75mA @ 3.3V.
If you use it with the traditional cheap GPS antennas widely available, you will not achieve the expected performance.
That being said, just connect the antenna to the SMA connector without using tools (the strength of your fingers is enough).
It is recommended to connect the antenna before powering the board.

The installation of the antenna is also a key point to achieve the best results.
The GPS/GNSS antenna should always be installed with the maximum possible view of the sky.
In addition, if possible, it should be installed with a metallic plane behind, e.g. rooftop of the car, on a metal plate bigger than 20cm, etc.

If you want to learn how installation impacts performance, please have a look at our GPS/GNSS antenna installation guide.

XBee Antenna

If you own a simpleRTK2B LR Kit, you will also have an external antenna for the radio. Just screw the dipole antenna to the SMA connector using the strength of your fingers.

How to optimize the range:

  • The antenna should be mounted vertical.
  • It is recommended to install the antenna in a location where it always has line-of-sight with the other device.
  • Increase the distance to the ground, by installing it in an elevated point.

If you want to learn more about how installation impacts performance, please have a look at our XBee antenna installation guide.

LEDs

The board includes 3 status LEDs, which indicate that:

  • GPS FIX: u-blox default configuration for TIMEPULSE pin is used: OFF when no fix, 1-pulse-per-second when valid position.
  • NO RTK: u-blox default configuration for RTK_STAT pin is used: OFF when RTK fix, blinking when receiving RTCM data, ON when no correction.
  • RTCM IN: The simpleRTK2B is receiving data from the radio connected on its TOP XBee socket.