HARDWARE

  KEYPAD INPUT RESULT

For the keypad, encoder keypad is being used to encode 8 data from the keypad (4 bits data row and 4 bits data columns). A Data Available output goes high when a valid keypad entry has been made. The Data Available output returns to a low level when the key entered is released, even if another key is depressed

OUTPUT VOLTAGE OF KEYPAD 

TRANSMITTER

TRANSMITTER TRANSMITTING THE SIGNAL

The transmitter goes high when transmitting the signal to the receiver. The transmitter will able to transmit the signal when it has enough voltage

    RECEIVER

RECEIVER RECEIVES THE SIGNAL

Receiver also active high when receives the signal. Figure 24 shown that value of voltage is 1.69 volts. Therefore, receiver fast detected the signal from the transmitter. Low supply voltage from input power causes lagging in receiving the signal.

SCHEMATIC DIAGRAM AND PCB LAYOUT FOR RECEIVER