One of our customers from Croatia thought up a rather creative use of the UniPi for his standalone parking system. The project, which also served as a topic of his university thesis, combines open-source software and modern IoT hardware.
Hardware and software
The system consists of RS232-compatible barcode readers, barcode scanners, serial printer for barcode tickets, LCD monitors, inductive loops and various additional hardware. The core of the system is a pair of UniPi controller boards, using Raspberry Pi as the main CPU.
As to software, the whole system is built on OpenSUSE distribution of Linux OS. Upon it, a custom-made software solution is used in combination with open-source platforms. Necessary operations are then handled by a POS application written in Lazarus IDE.
HOW DOES IT WORK
When a vehicle arrives, outside inductive loops send power-up signal to the barcode ticket printer. The driver then prints the ticket by pushing a button on the printer. After printing of the ticket, entrance gate is automatically opened for the vehicle to drive in. Inside inductive loops then detect the passing vehicle and send signal to close the gate.
When a vehicle is leaving, its driver scans his barcode ticket on a parking meter. Operator in the parking booth process the payment and gives the driver an exit barcode ticket. Upon arrival to the gate, inside inductive loops again send a signal to a barcode scanner. The driver then scans his ticket to open the gate. After the vehicle passes by, outside inductive loops send a signal to close the gate and after its closing, the whole system is set back to standby state.