I’ve just got Open Bench Logic Sniffer and tried to capture some I2C data from my current project.
I connected probes to the header, and wired GND, SCL and SDA to my board. Surprisingly, I didn’t get quite the data I expected. And I’ve got some strange “noise” signal on disconnected probes 2-6 (7 is down because of RLE). It somewhat resembles the data on connected 0 and 1.
Then I thought: that’s weird, I didn’t expect that. And connected probe 2 directly to the same GND pin. So GND and channel 2 to are connected to the same power source, and I expect it to be 0.
Strangely, it’s not. There’s something weird going on. Did I get a damaged board that plays? Or something is wrong with my software?
I used the latest Logic Sniffer OLS 0.9.5. Attached is the data file from session I recorded (actually, it’s not .txt, it’s .ols - but the forum doesn’t allow to use .ols extension).