This is the improved Quad Stall Motor Controller w/ point Sense base board for the  

Pocket Beagle. It uses  TC4428's to drive the Stall Motors and uses 

SN74AHC00N's wired as RS FlipFlops to debounce the point sense (assumes a SPDT 

switch mechanically connected to the points (or the internal switch in the 

Stall Motor). Uses 8 GPIO pins:                                               

GPIO20: P1-20 Motor1                                                         

GPIO23: P2-3 Motor2                                                          

GPIO45: P2-33 Points1                                                        

GPIO46: P2-22 Points2                                                        

GPIO26: P1-34 Motor3                                                         

GPIO27: P2-19 Motor4                                                         

GPIO47: P2-18 Points3                                                        

GPIO44: P2-24 Points4                                                        

GitHub Projecct:                                                               

https://github.com/RobertPHeller/RPi-RRCircuits/tree/master/PocketBeagleQuadSMCSense   

Mouser Projects (parts):                                                        

https://www.mouser.com/ProjectManager/ProjectDetail.aspx?AccessID=330542c522

https://www.mouser.com/ProjectManager/ProjectDetail.aspx?AccessID=82b1e6b259

https://www.mouser.com/ProjectManager/ProjectDetail.aspx?AccessID=330542c522

OpenMRN program: QuadSMCSenseOpenMRN, on GitHub at:

https://github.com/RobertPHeller/RPi-RRCircuits/tree/master/QuadSMCSenseOpenMRN