cyclic redundancy check program in c with explanation

In the current case, the generator polynomial 1011 has a total of 4 digits, which means that the CRC value has 3 digits. This CRC value is one digit smaller than the generator polynomial. An additional CRC value is appended to each data packet that is to be sent. The procedure is the same for each data packet. I have chosen the polynomial 1011 for the sake of simplicity: It is important that the generator polynomial for sending the data and for receiving the data is identical. The generator polynomial can be chosen freely, but some polynomials have proven to be particularly suitable. For example, the data packet 10010101 corresponds to the following polynomial:Ī so-called generator polynomial is required for the calculation of the CRC.

In principle, the calculation is a polynomial division. This might also be interesting for you: Setting a precise clock frequency for an ArduinoĪlso closely related to this article: Setting a precise clock frequency for the Raspberry Pi Cyclic redundancy check – How it works: The CRC identifies that a data packet has an error and the receiving station will drop the packet.

For example, if bits have been swapped in a received data packet or a 1 has been received instead of a 0, this can be detected by the cyclic redundancy check (CRC for short).

I have already explained in previous posts how to set a precise clock frequency for the Arduino and the Raspberry Pi, to which I link below.Ī cyclic redundancy check is a simple and elegant way to verify that the data arriving at a receiving station is correct. In order for the data transmission to be possible, the clock frequency of the transmitter and the receiver must be precisely synchronized. I plan to build a transmitter and receiver station which is able to transmit data with the help of light signals (“Visible Light Communication” – VLC).

Cyclic redundancy check program in c with explanation