Wow, what a nightmare. I feel your pain. The manuals suck.

A couple thoughts;

When you use a Kangaroo attached to a Sabertooth there are two sets of dip switches that need to be set. The ones on the Sabertooth are set so the two boards can talk to each other. In think In reality the Kangaroo will only talk to the Sabertooth. It seems to me that the Sabertooth becomes the slave to the Roo.

When you use a Kangaroo attached to a Sabertooth set the dip switches on the Sabertooth as instructed in the manual, Then forget about the Sabertooth. 99% of the time you will never have to do anything again to the Sabertooth.

When you use a Kangaroo attached to a Sabertooth set the dip switches on the Sabertooth to:

Switches 1 & 2= Off Switches 3,4,5,6= On. This will set the proper baud rates and other setting so the Kangaroo and Sabertooth can talk to each other. At this point the Roo will be able to totally control the Sabertooth.

I've never had to change the baud rate for either board in the DeScribe software. Dip Switch control is the default. However if for some reason you need to change this and other settings that the dips control there is a box to check in the software that will override the dips.

The dips on the Kangaroo change the operating modes and options. I've attached that diagram from the Kangaroo manual showing them:

@DJ, I assume that you are controlling the robot with the joystick control in ARC. I think to achieve the control you want you need to set dips to 1=on, 2=on, 3=off, 4=off. This would give you Digital input, Encoder feedback, velocity control and mixed mode that would be like a tank control.  

After all this the device to be controlled needs to be set up 100% and working. Once that is certain then the Roo/ST can be attached and hopefully an Auto Tune can be successfully done.

You can also attach the input control wires to accept an RC controller. I did not use a Kangaroo for this on my robot's RC drive. Just a lone Sabertooth. DE says adding a Roo makes driving a robot much better when using RC control but I have not tried it. My large RC controlled robot runs nice and smooth with only a ST attached without the additional Kangaroo.

Again, I agree that the manual is very hard to read. Information is given in terms that is not very intuitive. Almost like the developer assumes you should already know this stuff. Also needed info is scattered around the manual. I found it was important to read through the entire manual to make sure I found the needed information or needed step. Example is how to attach the Roo to the ST and set the proper ST dip switches. That information at the end of the manual!

Here's some links to the Kangaroo and DeScribe manuals just in case you need them: Kangaroo X2 Manual DeScribe Manual

It was a fun show. Thanks for doing this live hack.

@DJ

In your post above ... #3. The top picture, shows the Sabertooth, Kangaroo and Arduino setup.

What is the code that is on the Arduino? (In the video you use a generic h-bridge.)