2.3 SD card slot
Raspberry Pi는 운영체제를 설치하거나 필요한 자료를 저장하기 위한 저장장치로 flash memory의 일종인 SD card를 지원한다. SD card는 용량이나 성능 면에서는 hard disk에 미치지 못하지만 일반 hard disk에 비해서 전력소모가 아주 적다는 장점이 있다.
Raspberry Pi_Kor_02.1.2 Raspberry Pi의 model 특성 비교
2.1.2 Raspberry Pi의 model 특성 비교
● Raspberry Pi 1 model A와 Raspberry Pi 1 model B의 특성
장치
Raspberry Pi 1 model A / A+
Raspberry Pi 1 model B / B+
SoC
Broadcom BCM2835
Broadcom BCM2835
CPU
700MHz Single-Core
ARM 1176JZFS
700MHz Single-Core
ARM 1176JZFS
GPU
400MHz VideoCore IV
400MHz VideoCore IV
Raspberry Pi_Kor_02.1.1 Raspberry Pi 기본 구성
2.1.1 Raspberry Pi 기본 구성
Raspberry Pi가 가지고 있는 hardware는 model에 따라서 약간의 차이는 있지만, 기본 틀은 이전과 동일한 체계를 유지하고 있다. 하지만 최근에 Raspberry Pi의 인기가 높아지고, 사용처가 넓혀지면서 보다 고성능과 다양한 기능을 필요로 하는 요구사항이 제기되면서, 최신 model에서는 보다 고성능을 지원하고, 새로운 기능을 추가하기 위해서 hardware 구성이 약간씩 변화하고 있다.
Raspberry Pi_Kor_02.0 Chapter 2 Raspberry Pi 하드웨어
Chapter 2 Raspberry Pi 하드웨어
Chapter 주요 내용
Raspberry Pi는 아주 작고, 저렴하면서도 상대적으로 강력한 기능을 가지고 있다. 여기서는 Raspberry Pi의 hardware 구성과 각각의 특성에 대해서 설명하고 있다.
다음과 같은 항목에 대한 내용을 포함하고 있다.
■ Raspberry Pi의 하드웨어 구성
■ SoC, CPU 및 memory
■ SD card slot
■ power supply
■ 비디오 및 오디오 장치
■ USB port
■ network 장치
■ GPIO
Raspberry Pi_Eng_02.3 SD Card Slot
.3 SD Card Slot
Raspberry Pi supports SD card which is a type of flash memory for a storage device for installing operating system or storing necessary data. The SD card has less capacity and performance than a hard disk, but it has the advantage that it consumes less power than a normal hard disk.
In Raspberry Pi, an SD card has a special meaning, unlike in other computer systems. When Raspberry Pi is powered up and started for the first time, a special program called Boot Loader is supposed to read the operating system installed on Raspberry Pi from the SD card. If you do not have an SD card or you do not have the proper operating system installed on your SD card, you can not start the Raspberry Pi system.
Raspberry Pi_Eng_02.8 GPIO
2.8 GPIO
Raspberry Pi is not only able to use the resources in the system, but also has functions to communicate with various external devices and control them through the interface. It can process input or output with an external device, or adjust an external device. It is possible to implement a function of receiving various measurement values from an external sensor to judge a situation and performing appropriate processing accordingly. It is also possible to build a system that directly controls an external system by creating an Embedded Program.
Raspberry Pi_Eng_02.7.3 Bluetooth Device
2.7.3 Bluetooth Device
Recently, various peripherals support Bluetooth, and Raspberry Pi also provides Bluetooth function from Raspberry Pi 3 model B to support it. With this function, you can access Raspberry Pi by using external Bluetooth device such as mobile phone and utilize various functions.
Bluetooth provided by Raspberry Pi supports Bluetooth 4.1 and Bluetooth Low Energy (BLE).
In order to use Bluetooth, some additional setting is required. Please refer to [11.8 Configuration and Connection] for more information.
Raspberry Pi_Eng_02.7.2 Wi-Fi Device
2.7.2 Wi-Fi Device
Depending on the environment in which Raspberry Pi is installed, when Raspberry Pi requires a network connection function, there are many cases where it is more advantageous to connect wirelessly than to connect by wire.
From the Raspberry Pi 3 model B, Raspberry has built-in Wi-Fi that supports 802.11 b/g/n wireless LAN. Therefore, you can wirelessly connect to the LAN network without using additional Wi-Fi access devices and utilize the communication function.
To use Wi-Fi, you need to make some settings. Please refer to the description in [11.5 Wireless Connection] for more information.
Raspberry Pi_Eng_02.7.1 Ethernet Port
2.7 Network Device
2.7.1 Ethernet Port
As Raspberry Pi has been used for various purposes, it has become increasingly necessary to interwork with external networks to increase utilization.
Raspberry Pi is provided with an Ethernet port for communication using a LAN cable. The Ethernet port is available as standard starting with the Raspberry Pi 1 model B+ announced in mid-2014, and supports high-speed 100 Mbit/s Ethernet. If you do not need the network function, you can use the model A series.
When you connect a LAN cable to the Ethernet port and connect it to the network, it basically connects to the network and operates automatically. If you want to adjust the connection method, please refer to [11.4 Wired Network ConnectionWired Network ].
Raspberry Pi_Eng_02.6.2 Power Constraints of USB Port
2.6.2 Power Constraints of USB Port
The required power level of USB devices is defined in 100mA increments from 100mA to 500mA. When a USB device is first connected to a computer, it informs the USB Host of its required power requirements. In theory, the actual power used by a USB device should not exceed its self-defined limits.
The USB ports on the Raspberry Pi are designed to withstand loads of at least 100mA each, which is sufficient to operate low-power devices such as mouse and keyboards. However, devices such as Wi-Fi adapter, USB hard drive, and USB pen drive may consume much more power depending on the USB device. Thus, if Raspberry Pi’s own power is insufficient, it is good to use an external USB hub with separate power supply. Of course you can connect a USB device that uses 500mA power directly to the USB port of Raspberry Pi, and operate the USB device by supplying enough power to the Raspberry Pi, but if the power is insufficient, it is difficult to guarantee reliable operation.