434 / 315 MHz 8 Channel Secure Remote Control
NEX Robotics Pvt. Ltd.
5
www.nex-robotics.com
Reciver
Figure 4: 434 / 315 MHz 8 Channel Secure Remote Control Receiver
Remote control receiver has 8 logic output corresponding to 8 switches on the remote
control transmitter. When a particular key is pressed, bit corresponding to that number on
the reciver will become logic 1. Output of the HT648 decoder is buffered using IC
74HC245. Channel output status is also displayed on the LEDs. Output can drive any 5V
TTL / COMS compatible output. Reciver can be powered by 7 to 12V or by 9V battery.
Make sure that security bit settings on transmitter and reciver are identical. All the
security bits of the remote control transmitter and reciver are factory set at logic 0 or 1.
Low drop voltage regulator is used to down convert supply to 5V from 7to 12V input
supply. Remote is reverse polarity protected.
HT648 decoder chip receives the serial data from the wireless reciver and decodes it in to
parallel. If security bits are matched it makes pin VT as logic 1 and outputs the bits
corresponding to the switches on the remote transmitter.
Receiver has on onboard track antenna. To enable it you have to short pad as shown in
figure 5. For longer range you can solder wire on the pad marked as “ANT”.
Remove Jumper for LEDs (J1) to turn off the LEDs used for channel status indication.
