Question re: Arduino to Arduino I2C with Serial Monitor

[Electro Fan]

I've been trying to get this to work:



I can't get the decoder to read the correct values.

In this setup the IDE on the PC uses the Serial Monitor to send a simple "H" or "L" from the Master Uno to the Slave Uno.  The H or L travels through a (Com 6) port via a PC USB connection to the Master Uno, which passes it along to the Slave Uno.  The Slave Uno is apparently getting the code because it's L LED is turning on with the H and off with the L as it should.

I have used my Rigol 2072 to monitor the SCLK and SDA and the scope captures the waveform each time I toggle between H and L through the serial monitor.  At one point I fiddled with the Windows Device Manager port settings properties that allow you to turn off Flow Control or use Hardware or Xon/Xoff and I got a proper "H", but it must have been a random fluke because it wasn't repeatable.  Other symptoms are that the R/W address is not showing the correct address (should be 5).  Additionally, when I set the decoder to ASCII I don't get 1s and 0s.  Something I have done is goofed up, no doubt..... Suggestions appreciated.  Thanks


Update:  Binary is displaying as 1s and 0s - but not decoding properly.
 

[Electro Fan]

I used an Intronix LogicPort to monitor the Arduino to Arduino I2C connection and it shows that the H and L are being properly communicated between the two Arduinos.  So, I think the issue must be in something I have not set up properly on the Rigol.  There aren't that many settings on the Rigol but I'm sure I've missed something... 

Suggestions welcome.  Thanks!

[Electro Fan]

I turned the scope off and on and for a few shots it started decoding the H and L.  I twiddled with the trigger levels for SDA and SCLK and it seemed sensitive to that but the best results were near the middle of the waveforms (about 2.5V).  After a few successes it went into lala land.  I'm playing with the When, AddrBits, Address, and Directions settings but I'm not sure if I have those right - might be the settings where I'm off.

I think the answer might be sitting in the LogicPort images above.  I'm just starting to learn I2C and I'm not sure what the S, A, and P stand for; and I'd guess 2h might be code for the 5 address... but as you can see, I'm just guessin'.  Need some help from an experienced I2Cer,  Plz, Thx. 

Update:  Always good to Read The Fine Manual (Intronix has pretty good help/documentation).  S is start (duh), A is Acknowledge (sort of duh), HS is High Speed, and P is Stop (go figure).  Now I just need to figure out how to use this info to get the Rigol to do it's thing properly.

[Electro Fan]

Update:  on the digital channels of the MSO it decodes properly.  I think there is a noise issue on the analog side.

[Electro Fan]

Update:  in order to display the I2C address the Include R/W soft button needs to be set to Close.  In open it will still display an address but it will be 0x0A.