Can you add a second motor shield and have three boosters plus a program track. The second shield would be for dividing the power into sections on the layout. Will be using the Pololu MC33926. RCMan
Thanks: Forgot to add I have control boards for Points, and signals that I want to operate and power through a separate booster and not the main booster.
As long as they operate on a DCC signal that should be fine. You could configure the points as a turnout in DCC++ using either "<a [addr] [subaddr] [state]>" (treat it as a standard accessory decoder) or "<T [id] [addr] [subaddr]>". With the "<T...>" approach you would toggle the points via "<T [id] [state]>" (0 = closed, 1 = thrown). Internally DCC++ will convert it from "<T [id] [state]>" to "<a [addr] [subaddr] [state]>" and respond with "<H [id] [0|1]>" after it sends the DCC signal to the decoder.
Actually, I think this can be done with some jumper doubling and header pin bending. I've already changed my Pololu into a two Main output system with the Prog output on a switch so I can go back to one Main and one Prog when I need to - no sketch change necessary. I believe I can piggy back two more Pololus to make a one Prog, five Main District system in the same way. David
Sure can. No code change, just feed the Main PWM to both H bridges on the second shield. It amounts to bending the 'program track PWM pin a little, so it won't seat into the first shields socket. Then run a jumper from second shield's "main track' PWM socket to the 'Program track' socket (the pin you bent). So when done, both H bridges on the second shield are being feed with the same PWM signal. Bill PS The current feedback pins on the second shield should also be bent out, I think. The down side is the DCC++ BS Arduino won't be able to read the current on the other districts. I don't recall if anyone has solved this. Might want to look into using a booster that has over current protection such as Dave Bodnar's Booster, http://www.trainelectronics.com/DCC_Arduino /DCC_Booster/index.htm It uses a Pro mini Arduino to monitor current and provide over current protection.
