Splitting GPS Tx signal

I’m not sure if this is the right place to ask this, but I have a project with a PixRacer R15 and uBlox SAM GPS module in a mid-sized quad. We’ve got lots of flight time on the system without any issues. Recently we added a companion computer, and we tried splitting the GPS Tx signal, feeding the second drop into the Odroid, but now it seems that the PixRacer loses contact with the GPS module intermittently. It does not appear to be a GPS jamming issue, as the sat-count drops from mid 20’s to zero in a split second, and then recovers just as quickly, and there is a message in the logs stating that it detected a GPS module, pretty much like the message at boot. My guess is that the serial link is getting dropped, and Ardu thinks the module was removed and then added back in. We experienced this whether or not the Odroid is powered. Stupidly, we did not try cutting the line to the Odroid to see if that cleared it up, but I’ll test that out on the ground.

Digging around online, I’ve seen some that claim splitting the Tx line is not a problem, but others that claim an impedance mismatch can do pretty much what we are seeing. I’m just curious if anyone else has experience with this.

Hi @Kevin_Jones

True. Normally not an issue.
To identify the root cause of the problem take a scope and check the signal levels of the TX line with and without the Odroid.