To set up my Ardusimple, sourcing RTCM corrections from a local source, here’s what I learned:
I used a source https://cddis-caster.gsfc.nasa.gov/. I followed the instructions here https://cddis.nasa.gov/Data_and_Derived_Products/Data_caster_description.html to get a userid and login. I tested that the caster was running by using the GSFC recommended ntrip client, BKG Ntrip Client, and connected to the ntrip caster with that client and saw the messages coming in. All of this while waiting for the ArduSimple to arrive.
Then when Ardusimple arrived, I downloaded ucenter and hooked up my Ardusimple via USB (using the “Power+GPS” usb port) and connected the antenna. It started working right away without RTK fix. I was seeing a 2-3 meter drift.
Then I had to somehow connect u-Center to the GSFC caster. The GSFC ntrip caster is only available to connect to via SSL. Port 443. I tried entering the caster information (cddis-caster.gsfc.nasa.gov, port 443, username and password) into u-Center and it didn’t connect. I decided this was because u-Center doesn’t support connection via SSL. So I download stunnel from https://www.stunnel.org/ and set it up to connect port 8080 on my local machine to SSL port 443 on cddis-caster.gsfc.nasa.gov. stunnel configuration for this was as follows:
client = yes
accept = 127.0.0.1:8080
connect = cddis-caster.gsfc.nasa.gov:443
verifyChain = yes
CAfile = ca-certs.pem
checkHost = cddis-caster.gsfc.nasa.gov
OCSPaia = yes
Then I tell u-Center to connect to the ntrip caster on localhost, port 8080, and same username and password that I got from GSFC. Presto, it connected, and I see NTRIP client:localhost:8080 in the status bar at the bottom of uCenter.
But I didn’t get an RTK fix. Turns out that I had connected to a channel which wasn’t sending messages that the uBlox supported. (See my post in this forum about “finding caster sources near me”.)
So I switched to channel GODR2, and connected, and presto, got a 3D/FLOAT fix.
Great post, thanks for sharing this with the community!