i think you need power as i2c protocol is open drain, meaning that SDA and SCL lines are high when there is no communication, and any exchange is done by pulling them low. teletype will provide that voltage while trilogy/ansible wonât.
my assumption was that this configuration would be the same as using, say, ansible, just friends and teletype with a teletype i2c backpack together. changing ansible to run as i2c leader in this configuration does not affect the hardware. i assumed disconnecting teletype wouldnât affect anything on the i2c bus either, but perhaps this is not the case. i donât know much about the hardware side of things, so canât really comment.
@tehn - could you comment whether itâs safe to use trilogy/ansible as i2c leaders with powered i2c backpacks but without teletype connected?