01 August 2016 User ReviewCheck your delivery options:
Remote gate mechanism proposed in this circuit helps to prevent an unwanted access to controlled environments. This is achieved mainly through the use of a Radio Frequency (RF) transmitter-receiver pair. Remote gate mechanism can be useful in providing security for homes, organizations etc.At the remote section, we have 3 switches, an encoder IC and RF transmitter. OPEN and CLOSE switch for controlling the opening and closing of gate. OPEN and CLOSE switch is connected to D1 and D0 pin of encoder IC. Switch SW2 for enabling the data transmission. When power supply is provided, power led will turn on. HT-12E encoder IC will encode the state of switches along with the 8 bit address value and send to the RF transmitter. Here the entire address pin is grounded. HT-12E converts the 12 bit parallel data to serial. Of these 12 bits, 8 bit represents address and 4 bit represents the data. Serial data will be available at the DOUT pin of encoder IC. From the encoder IC, data will get transmitted through the RF transmitter.
Fig 1:SK_017_v1 Circuit Diagram
At the receiver side we have RF receiver, HT-12 D decoder IC, buzzer, power led and an H-bridge circuit. H-bridge circuit is provided for driving the motor in both directions. Serial data received at the RF receiver module is fed to decoder IC where it is converted back to parallel data. Decoder will verify the address bits and data bits will be available at D0-D3 pins. H bridge circuit is connected to D0 and D1 pin of HT-12D. Buzzer sounds as soon as the communication is established between transmitter and receiver. To open the gate, user must press the SW2 to enable data transmission. Then press the OPEN switch. Once we press the OPEN switch, then values at D0-D3 will be 1011. This 4bit data will be send along with 8 bit address value. T5 and T6 are NPN transistors and Q1 and Q2 are PNP transistors. Value at the D0 and D1 are ‘1’ & ‘0’ respectively. Therefore T5 and Q2 will turn ON and T6, Q1 will turn OFF. Motor rotates in one direction and gate opens. Similarly to close the gate, value at data pins D0 & D1 will be 0 and 1. T6 and Q1 will turn ON. Motor rotates in the reverse direction. Motor will rotates until we release the OPEN/CLOSE switches. Using this circuit we can effectively control the gate wirelessly.
Fig 3:SK_017_v1 PCB Top
Fig 3:SK_017_v1 PCB Bottom