I’m attempting to connect to a slave via the gen2_i2c bus, so I expect it to show up when I do a i2cdetect -y 2. I have already confirmed that this command works with a Raspberry Pi and the slave responds with address 0x08, as I expected.
When I put a voltmeter on the pins (SCL: 18, SDA: 20, J3A1 header) I see that they are already sitting at 3.3V, so I’m assuming they are already pulled up to the 3.3 V source and that I do not need a level converter.
So the connections I have between the Jetson and my slave are SCL, SDA, 3.3 V, and GND. This configuration, without the 3.3 V line, works for me with the Raspberry Pi.
If I put an oscilloscope on the lines and do an i2cdetect -y 2 I see no change. If I try i2cdetect -y 1 then I see square pulses on SCL, but only noise on SDA.
Looking at the device tree I see that both the SDA port and the SCL port are configured to open drain.
What am I missing here?