This application discloses a payment module with one or more processors, memory, a short-range wireless transceiver configured to communicate with one or more mobile devices, and a first interface module configured to output to a control unit of the offline payment-operated machine one or more electrical pulses. The payment module receives a wireless request via the short-range wireless transceiver from a respective mobile device of the one or more mobile devices to initiate a cashless operation of the offline-payment operated machine. In response, the payment module causes the offline payment-operated machine to initiate the requested cashless operation by issuing a first number of electrical pulses to the control unit via the first interface module. Further, in response to the wireless request, the payment module sends operation information corresponding to the initiated operation of the offline payment-operated machine to the respective mobile device via the short-range wireless transceiver.