Raspberry Pi PWM HAT with modification 

16-channel PWM/Servo HAT with modification (right side). Across the bottom are the 16 sets of 3-pins, each to control a servo, which will change the aspect of a semaphore signal. On the right edge 17 GPIO pins are brought out to control 12 LEDs for the "Parking Lot" signals, 4 LEDs for traffic monitoring and 1 pin for the fan control push button. On top are the 40 pins interconnecting the Pi underneath and the bonnets on top. On the left are an input plug to provide 5vdc to power the servos and a terminal block to daisy-chain 5vcd to the PWM bonnets and IO Pi Plus HAT..