I’m testing the i2C connection between a 16n and a Teletype, without success so far :
FB 1 or any other fader always returns 0
The 16n is connected to a TT busboard on the back of a Teletype (not the latest revision).
The other modules connected to the backpack work properly, I mean that I can send I2C commands from Teletype, as usual. There’s an ER-301 on its own header, and two TXo in series connected to another header.
No issue with USB and CV. The Pull up resistors are not placed on the 16n. The firmware has not been modified.
The cable connecting the 16n to the teletype is very short (see photo), 15cm outside + 20cm inside. I double checked the connections with a multimeter: tip SDA, sleeve ground, ring SCL.
Am I missing something here ? I’m gonna try to connect the 16n to one of the TXo maybe
Each test failed 
Should I open an issue on Github @infovore ?
EDIT:
I’ve enabled “debug”, but nothing is printed in the serial monitor when I type FB 1 on the Teletype.
I’ve checked the connections again between the busboard and the Teensy.
I used 1N4148WQ-7-F diodes instead of 1N4148W-7-F but the specs are nearly identical.
I anybody has an idea…
Edit: issue created on GitHub, probably more handy 
Edit 14/01/19 : Fixed