Beep aWay
Technical Framing
In the beginning of this project it was necessary to perform an extensive research to understand the functioning of radio frequency and its communication between the transmitter and the receiver. Since we had access to laboratories, we took the opportunity to do some testing in order to understand some concepts that were not clear from research done previously.
We use a 434MHZ transmitter and receiver, typically used in remote controls.
With the use of an oscilloscope we were able to understand that the signal emitted by the transmitter is a sinusoidal wave analog signal. The receiver receives this signal and turns it into a square wave digital signal. It is with this digital signal that it is possible to send an information-bit code or even strings.
Since the goal is to identify a specific danger and as there are several transmitters 434MHz that we can not control, we had to enter a 4-bit code by an encoder, HT12E, on the transmitter. This code is always the same so the receiver when catching a signal with the same frequency, sends it through a decoder, HT12D, which decrypts this code in the signal. If the receive code is equal to the pre-set code from the transmitter, warns the proximity of the person a danger.
