Now we will connect the Translate and Rotate nodes. Select Translate in the Outputs column and then select Translate in the Inputs column. Now they should be connected. Do the same for Rotate. In my case the Outputs column was on the left and the Inputs column on the right. Yours could be the other way around, so just check to see where they are.
Once that is done, you can close the connection editor. Now we just need to move the FootCTRL pivot point. So we select the FootCTRL circle and then hit the Insert key and move the pivot point to the Heel Joint.(Remember to always press the Insert key again when the pivot point is in place, so that you exit pivot mode). Once that is done, move the FootCTRL circle around and see what happens. Cool hey? The circle now becomes the foot controller. You can move it and rotate it.
We will now setup the set driven key for a FootRoll
5. Set Driven Key
This is our final step. We will be setting up a FootRoll using set driven key. Lets clean up our FootCTRL first. We will remove the Scale attribute from the controller because we will not be animating or using it for that matter, so lets hide it and lock it. Select the FootCTRL and in the channel box, select the Scale X, Scale Y and Scale Z attributes. You can do so by clicking on Scale X and dragging all the way through to Scale Z. With those selected, right click in the channel box and go to "Lock and hide selected" Now the scale attributes should be removed (Hidden) from the channel box and if you select the scale tool, it will show up in the viewport as grey. Which means that it is locked.
Now we will add the "FootRoll" attribute. With the FootCTRL selected, go to..Modify > Add Attribute. When the window opens, type in FootRoll in the attribute Name row, and then assign values of -15 and 15 to Minimun and Maximum and a 0 for Default in the Numeric Attribute Properties tab. Leave everything else at default. See pic below for settings.
Once that is done, click OK. Now if you look in your channel box, you will see a FootRoll attribute. If you select it and move and drag to 15 and -15 you will notice that it does nothing. Well, thats because we have to setup the set driven key for that attribute. With that in mind, lets bring up the Set Driven Key window. Animate > Set Driven Key > Set. Don't click on Set, instead, click on the little option box next to it so we can go into the Set Driven Key window.