Asynchronous wirless TTL data transceiver

Asynchronous TTL data transceiver Components of the system 1. Transmitter board The transmitter will be reading asynchronous TTL signal from 2 TTL lines, incoming data string will be in wiegand format. The length of this wiegand packet should be possible to adjust in the software or it can be automatic where the transmitter sends the received data after the wiegand string is over. Wiegand string will be generated one by one and there will be at least 1 second gap between each string. Transmitter unit will be portable & the wiegand string will be coming from a card reader, the user will be using this portable reader to read users cards & the card reader will generate wiegand string for each successful read; if the read is not successful then no wiegand will be generated. Distance between the portable Transmitter unit & the receiver is 20-30 m where the receiver unit will be placed inside the gatehouse while the portable unit will be moving outdoor around the gatehouse, mostly inside a bus or a truck. 2. Receiver board Receiver board should receive the information & re-produce the wiegand string at the output pins, green molex connectors or equivalent is required to ensure easy wiring to the final control panel inside the gatehouse. The receiver should acknowledge the receipt of the transmitted string by sending an acknowledgment packet to the transmitter, then the transmitter should give an indication that the string is delivered, this indication can be a TTL signal output that is connected to LED. When the transmitter starts working it will seek the receiver unit & once it is connected to it an indication must be given at the transmitter side this indication can be a TTL signal output that is connected to LED; so the user can make sure the transmitter is paired. 5 Portable readers are required to operate around one gatehouse. WiFi access point can be used if the system to be based on WiFi. Zigbee and other technologies are possible as well.. Note, the transmitter will be enclosed with metal and plastic material. Wireless technology Wireless transmission used should ensure that the signal is strong enough to have good communications between the transmitter & the receiver. It is highly recommended to use a wireless boards that offers different antenna types.