Why do we need an SD card for the Raspberry Pi. Pro Preview

With the set for the course, you also have an SD card. It is important that you understand why and how is the SD Card is used. 

  • #720
  • 12 Feb 2018
  • 2:00

TL. DR.

The SD card contains the operating system for the Raspberry Pi. The operating system helps us communicate with the Raspberry Pi hardware.

The software of the Raspberry Pi

When you unpack the Raspberry Pi it comes with the processor and internal memory over an integrated circuit board. But it does not have any hard disks. It does not know what program to execute. It is just electronic elements to which we've applied some current after powering it on. The next step is to tell the Rapsberry Pi what to do. The contemporary processor receives instructions. Instructions that are written in a special language that the Raspberry PI can understand. 

Here is how this instructions look like (the first very few of millions like this)

00000000: 00011111 10001011 00001000 00000000 01101100 01010111  ....lW
00000006: 11011110 01011000 00000000 00000011 11101100 10011010  .X....
0000000c: 11001001 11001010 11100100 01011000 01110110 11000111  ...Xv.
00000012: 11010011 11110100 11000110 01111100 01100000 10111111  ...|`.
00000018: 01000001 11100011 11011100 11011001 00100000 10110010  A... .
0000001e: 00110100 01001011 10100001 10000010 00001111 00011100  4K....
00000024: 10010010 01000010 11110011 00111100 01000100 01001000  .B.<DH
0000002a: 11000010 01010000 01001000 10100001 00111001 00110100  .PH.94
00000030: 11001111 00010010 10111001 11110000 11011110 01101111  .....o
00000036: 11100000 01010101 10111111 10001010 11111101 00100000  .U... 
0000003c: 01111110 00000011 10101111 10111101 01110101 11100100  ~...u.
00000042: 10010111 01011101 11000110 01101101 00101000 01011100  .].m(\
00000048: 10111000 00110010 10101011 01101000 10011100 00000111  .2.h..
0000004e: 01000010 00010111 01001101 11011100 01111011 11111000  B.M.{.
00000054: 11011101 11110011 10111111 01000111 11110111 11000100  ...G..
0000005a: 01110111 11100011 10011000 10000011 11101111 10111110  w.....

...and millions more here

If you've ever heard that the computer uses 0s and 1s to work, here are the 0s and 1s. What the processor will do is to read these instructions from the external memory. This is something that the processor knows how to do. Each sequence of 0s and 1s means something for the processor. Each sequence is an instruction for the processor what to do.

Should we prepare these instructions ourselves? No. They are already prepared for us. We just need to copy them to the SD card and place the SD card in the Raspberry Pi.

 

 

English

With the set of the course you also have an SD card. It is important that you understand why and how the SD card is used. In a very short summary the SD card contains the operating system for the controller. The operating system helps us communicate with the Raspberry Pi hardware. When you unpack the Raspberry Pi it has a central processing unit and some internal memory. But it doesn't have any hard drives. It does not know what program to execute. It's just electronic elements to which we've applied some current through the power bank. The next step is to tell the microcontroller what to do. The contemporary central processing units receive instructions that are written in a special language that the microcontroller could understand. If you've ever heard that the computers are using 0s and 1s, this is the exact place at which we can discuss this. Because the instructions that the microcontroller will execute are written in a special language with 0s and 1s. These are just instructions that the microprocessor could follow and could execute. Each sequence of 0s and 1s means something to the central processing unit. Each sequence is an instruction for the central processing unit and what it should do. Should we prepare these instructions ourselves? No, they are already prepared for us. We just need to copy them on the SD card and to place this SD card in the Raspberry Pi. After we place the SD card in the Raspberry Pi it will start processing the instructions that are written on the SD card.