RF Controlled Robot

During my robotics course this semester, my team was given a task to build a Radio Frequency (RF) controlled robot. Many may call it a remote controlled robot. But it is one and the same thing.

So what we did: We took up a chassis with 4 wheels and 2 motors and hooked up a microcontroller board on it.  We bought a 315MHz RF transmitter and receiver module from a hobby shop. The receiver was connected to a decoder chip called HT12D and the output was HT12D was given to the microcontroller.

The remote had 4 push button switches which were connected to the HT12E Encoder chip. The encoder chip can encode up to 256 different messages. We had just 4. So the 4 push button switches were 4 logic levels and the Data out of the encoder was connected to the 315MHz transmitter module. So if none of the switches are pressed, the data out was 0000. If 2^nd switch was pressed, then 0100 and so on. Hence these messages were decoded and the robot moved according to the pattern transmitted.

Both the receiver and transmitter modules had antennas and the system worked perfectly without any lag.