Can Raspberry Pi (Raspberry Pi) be like an Arduino external sensor, controller?

The answer is yes.

There are 26 pins on the Raspberry Pi Board, these gpio (general purpose I/O) including SPI, I²c, serial UART, 3V3 and 5V power supply.

Domestic forum There is an article "RASPBMC Setting Infrared receiver" describes how to install the RASPBMC operating system for Raspberry Pi, install the infrared receiver for remote control.

The following figure defines the 26 pin pins for the Raspberry Pi

Raspberry Pi is much more expensive than an ordinary Arduino motherboard, and if you are afraid of accidentally burning out the Raspberry Pi, you can install the Arduino adapter Board (bridge) on the Raspberry Pi.

Reference:

Starter Book Getting Started with Raspberry Pi

Raspberry Pi to Arduino Shields Connection bridge
http://www.raspberrypi.org/phpBB3/viewtopic.php?f=59&t=19724

Taobao Raspberry Pi Adapter Board Raspberry Pi Shield for arduino￥120.00
Http://ukonline2000.taobao.com

Raspberry Pi Forum
http://www.shumeipai.net/forum.php

RASPBMC setting up an infrared receiver
Http://www.shumeipai.net/thread-12265-1-1.html

RPi low-level peripherals introduces 26 pin pins for Raspberry Pi
These GPIO (general purpose I/O) signals on the 2x13 header pins include SPI, i²c, serial UART, 3V3 and 5V power.
Http://elinux.org/RPi_Low-level_peripherals#GPIO_hardware_hacking
http://www.raspberrypi.org/archives/384