Blog | Raspberry Pi
The new systems were intended to work without any hardware to count people coming through the turnstile. The chip card or barcode were all that was needed to count people going through the gate.
However, sometimes this is not appearing to be practical where operators are also collecting money. They sometimes forget to swipe the ticket and hence the overall count is not getting updated.
To get round this we need to add : COMUS (ASSEMTECH) MCS-136-1AR PROXIMITY SWITCH & MAGNET, ARMOURED, N/O
This will be attached to the gate mechanism such that when the turnstile rotates a signal will be picked up by a GPIO pin on the Pi. The application will then count this and send back the total gate count to the server in the Control Room. This switch is Normally Open, so the Pi will detect when this is closed.