SparkPNT FPX/FPM Base Cast

Positioning and Navigation
1

Hi,
I would like to setup the base cast mode in order to send base corrections over wifi through QGround Control.
Does anyone knows how to properly setup this mode?
I’m using NTRIP Checker to test the base setup, but it requires:
-User, password and mountpoint but I cant find which credentials to use when in this mode.
Thanks!

2

Hi Daniel,

I just downloaded NtripChecker and walked through this myself.

First, make sure the unit is in the right mode. Easiest way on the FPX: press either button to open the display menu and select Caster (shown as BaseCast on some firmware versions). Alternatively, from the web config page (192.168.4.1 on the unit’s “RTK Config” WiFi), open System Configuration, set System Initial State to Caster, Save Configuration, Exit and Reset.

This one mode change does everything: base mode, internal NTRIP caster on port 2101, and the unit broadcasts its own WiFi access point. Leave NTRIP Server, TCP Server, and WiFi Networks alone; those are for other setups.

Quick check before touching the app: once survey-in completes (about a minute under open sky), the unit’s display shows an RTCM counter increasing every second. That’s your base transmitting.

Then in NtripChecker, with your phone joined to the WiFi access point the unit now broadcasts (not your home WiFi):

  • Caster and login: Caster 192.168.4.1, Port 2101, Username and Password blank. Next.
  • Location: allow location or accept what it shows. Next.
  • Mountpoint: the app pulls the list straight from your unit. Select [MOUNTPOINT] and connect. You’ll see RTCM messages counting up, same stream the display is counting.

QGroundControl takes the same settings under Application Settings > RTK (NTRIP section); if you don’t see NTRIP options there, update QGC.

One tip since you’re mapping: survey-in positions the base to only a meter or two, and your whole map inherits that offset. For real flights, set the base on a known point in Fixed mode, or feed it corrections during survey-in, so your maps land where they should.

Docs: Base Menu - SparkFun RTK Everywhere Product Manual

Let us know how it goes.

3

Hi Juan,

Thanks for your reply. I’ve tried the steps you described. I didn’t manage to get NTRIP Checker working, but I did get QGroundControl up and running, which was my main objective.

Question on Base Assist:
Do you know if Base Assist would work with the following method?

  1. Start the FPX in Rover mode, connect with SW Maps, and get corrections via NTRIP or radio.
  2. Once the FPX achieves RTK Fix, switch to Base Assist to “grab” those precise coordinates and use them as the fixed position for the new base.
  3. Switch to Base Cast to start streaming corrections to the drone controller.

My main question is whether switching to Base Cast in step 3 preserves the fixed coordinates set by Base Assist, or whether it re-triggers a new Survey-In and discards them.

For future reference, here are the working QGroundControl NTRIP settings for anyone else setting this up with Base Cast mode:

  • Host address: 192.168.4.1
  • Server port: 2101
  • Username: (leave blank)
  • Password: (leave blank)
  • Mount point: SparkBase

Thanks again for the help!

4

Hi Daniel,

Quick follow-up: I just ran your exact workflow on my FPL to confirm.

  1. Rover mode, NTRIP corrections through SW Maps, waited for RTK Fix.
  2. Switched to Base Assist , it grabbed the current coordinates as the fixed base position.
  3. Switched to Base Cast.

To answer your question, Base Cast did not start a new Survey-In. It carried the Base Assist coordinates straight through. The tell on the display: if no Survey-In countdown appears when you enter Base Cast, your Assist coordinates are what the base is transmitting.

One more tip if you plan to repeat work on the same site. Base Assist grabs whatever the position is at that exact moment. Run it again tomorrow and the coordinate will land a few centimeters away from today’s. To avoid it you could make the coordinates permanent. In the config page, open Base Configuration, set the base type to Fixed, and paste in the coordinates you originally captured under RTK Fix. Save them to the Commonly Used Coordinates list with a site nickname while you’re there.

After that, no rover session and no Assist step. Set the unit on the same mark, power on, enter Base Cast, and it starts transmitting from the identical coordinates within seconds. Every flight lands in the same reference frame, which is what you need when comparing flights over time.

Thank you for your QGround Control NTRIP contribution!