Hi Kram,
Oh good, this makes more sense now.
Have you tested using other PiicoDev connectors (using just the TMP117 module)?
Have both of the PiicoDev modules got the correct address configured? Older modules have a cuttable track on the back of the module (don’t cut it if you want the default address). Newer ones have dip switches.
If yes to both of the above, then it seems something along the common path is not working properly. Could you do a continuity test with everything connected (no power) between these pins (GND and 3.3V tests should be 0ohm. SDA and SCL will either be 0ohms or 120ohm depending on the version board you have - both the same though):
If that checks out, then with everything connected and power applied, measure the 3.3V voltage between these two pins (should measure 3.3V):
Fyi, while there are pull-up resistors on the PiicoDev adaptor for RPI, PiicoDev modules have them as well. I wouldn’t expect to see the symptom you have reported for 1-2 modules if there was an open circuit fault with either pull-up resistor due to a soldering issue (so not suggesting a test for them).
