Hello,
I am using Xprotolab through USB into linux. I want to sniff Arduino-to-OLED display I2C signal.
The manual states to connect all of the grounds, so I have the 4 ground pins under the buttons grounded as well as the ground pin sticking out of the side (all wired to same protoboard rail). I assume these are connected to USB ground in the device.
The AWG is picked up fine through either CH1 or CH2.
I have an Arduino I2C OLED display powered at 3.3V, the display works and the software says the voltage is ~3.3V.
When I connect either CH1 or CH2 to the clock or data I2C, what do I use for ground for that probe channel? The Arduino is run off of battery, so ground is different than the ground coming through the USB into the Xprotolab.
Do I connect CH1 ground to the same ground as OLED, or do I ground the whole Xprotolab to the OLED ground?
?

Connecting all of the ground pins is only recommended when doing analog measurements. For I2C sniffing, you are fine by using the ground pin from the logic port./\r\n/The I2C sniffer does not use the analog channels (CH1 or CH2), but pins 0 and 1:/\r\n/Logic Channel 0:??? I2C Sniffer signal: SDA/\r\n/Logic Channel 1:??? I2C Sniffer signal: SCL/\r\n//\r\n/Here is a video where I demonstrate the I2C sniffer:/\r\n/