2.5.4 3.5mm audio jack and composite video
Raspberry Pi는 stereo를 지원하는 3.5 m audio jack을 제공하고 있다. Raspberry Pi에서 HDMI 출력을 사용할 때 audio 출력도 비디오 출력과 함께 HDMI port으로 전송하여 외부기기에서 비디오와 음성이 함께 출력되도록 할 수도 있다. 하지만 스피커와 헤드폰 등 별도의 audio 출력이 필요한 경우는 audio jack을 통하여 음성이 별도로 출력되도록 할 수도 있다.
2.5.3 DSI display port
Raspberry Pi는 TFT-LCD display를 지원하기 위해서 DSI(Digital Serial Interface) 접속을 지원한다. 장치를 연결할 때는 인쇄회로 기판의 윗면에서 SD card slot의 바로 위에 플라스틱 레이어로 보호되어 있는 DSI display port에 작은 리본 커넥터를 이용하여 연결할 수 있다.
2.5 비디오 및 오디오 장치
2.5.1 HDMI video port
과거에는 VGA/DVI 모니터들이 많이 사용되는 비디오 장치였지만, 최근에 나오는 거의 모든 모니터들은 고해상도 화면을 보여주는 HDMI (High Definition Multimedia Interface)를 지원하고 있다. Raspberry Pi 도 Full HD 1920×1080 해상도를 제공하는 Full HDMI 출력을 기본 비디오 출력으로 설계되어 있으며, 이를 지원하는 HDMI port를 기본으로 제공하고 있다.
Chapter 2 Hardware of Raspberry Pi
Chapter’s Main Topics
Raspberry Pi is very small, inexpensive and relatively powerful. Here this chapter describes the hardware configuration of Raspberry Pi and their characteristics.
It includes descriptions on the following topics:
■ Hardware configuration of Raspberry Pi
■ SoC, CPU and memory
■ SD card slot
■ Power supply
■ Video and Audio devices
■ USB port
■ Network device
■ GPIO
Chapter 1 Overview of Raspberry Pi
Chapter’s Main Topics
This chapter describes the birth background and development history of Raspberry Pi, and explains why Raspberry Pi has become popular worldwide now.
It includes descriptions of the following subjects:
■ Birth of Raspberry Pi
■ Development history of Raspberry Pi
■ Features of Raspberry Pi
Table of Contents
Preface
1. Up to the Point of Writing This Book
2. Overall Composition of This Book
3. What This Book Covers
4. Level of Content Covered in This Book
5. Conventions Used in This Book
Chapter 1 Overview of Raspberry Pi
1.1 Overview
Preface
Main Topics
First, here introduces the motive with which the author wrote this book. Next, this provides an overview of the overall structure of the book and summarizes the contents in each chapter and provides guidance on the level of content covered.
It includes descriptions on the following topics:
■ Motive of writing this book
■ What this book covers
■ Level of contents covered in this book
■ Conventions used in this book
25.9 Action
25.9.1 Relay
This subject is a top-level topic and is not appropriate to describe here, so I will have the opportunity to elaborate further in other books.
25.9.2 Actuator
25.8.3 Utilizing Digital DHT11 Humidity/Temperature Sensor
25.8.3.1 Feature of the Sensor
Here, we will use a module that integrates DHT11 sensor and other necessary components on a small PCB as shown below. The DHT11 sensor is equipped with resistive humidity measurement components, NTC temperature measurement components, and a high-performance 8-bit microcontroller and provides precise digital signal output. The DHT11 sensor originally has four wires, but this module has three wires.
25.8.2 Measuring Temperature with Digital Sensor DS18b20
25.8.2.1 Features of DS18B20 Sensor
There are many sensors to measure temperature on the market, but Raspberry Pi does not have an ADC (analog to digital converter), so analog temperature sensors like TMP36 can not be used directly.
Here we will measure temperature by connecting the digital sensor DS18B20 directly to Raspberry Pi.