Rasperry pi

與Arduino稍有不同的是，這是源於英國中學的開源項目，用900M ARM CPU，可以解碼高清視頻。缺點是3.3V，I/O電流小（可用TXB0108 轉為5V，但I2C不行），開發也較複雜。它可直接裝Linux（wheezy raspbian或Ubuntu core）/Android/Windows 10 loT core做開發應用，微軟也賣硬件。如果選擇的話，能用Arduino完成的就別用RasberryPi。比如實時性的，Rasberry PWM的周期就很慢。

變種硬件，如國產Banana Pi，硬件挺好，軟件/支持/和壽命難說。http://www.leiphone.com/news/201406/raspberry-pi-geek-other.html  http://www.udoo.org/ 

Rasperry Pi用Python編程, IDE: https://blog.idrsolutions.com/2014/12/top-8-ides-programmers-coders-beginners-raspberry-pi/ 

支持ZFS: https://www.raspberrypi.org/forums/viewtopic.php?f=63&t=19062 

SATA multiplier JMB321： http://www.htpcguides.com/rebuild-bananian-kernel-with-sata-port-multiplier-support/ 

多OS支持：https://books.google.com/books?id=zXz5CwAAQBAJ&pg=SL1-PA1&lpg=SL1-PA1&dq=Raspberry+Pi+2+開發 

入門：https://sites.google.com/site/raspberrypidiy/extend 

http://www.cl.cam.ac.uk/projects/raspberrypi/tutorials/temperature/ 

Rasperry Pi 3：

https://www.raspberrypi.org/blog/raspberry-pi-3-on-sale/ 

3.3-5V i2C converter:

GPIO: http://www.cl.cam.ac.uk/projects/raspberrypi/tutorials/temperature/#exampleCode 

## button.py
# import necessary library
import RPi.GPIO as GPIO   
import time   
# to use Raspberry Pi board pin numbers
GPIO.setmode(GPIO.BOARD)   
# set up pin 11 as an output
GPIO.setup(11, GPIO.IN)
# enter while loop unitl exit
while True:
# set up input value as GPIO.11
   inputValue = GPIO.input(11)
# when user press the btn
   if inputValue== False:
# show string on screen   
      print("Button pressed ")
      while inputValue ==  False:  
# Set time interval as 0.3 second delay
            time.sleep(0.3)   

##Blink.py
# import necessary library
import RPi.GPIO as GPIO   
import time   
# to use Raspberry Pi board pin numbers
GPIO.setmode(GPIO.BOARD)   
# set up pin 11 as an output
GPIO.setup(11, GPIO.OUT)
# enter while loop unitl exit
while True:
# Make an LED flash on
   GPIO.output(11,True)  
# Set time interval as 1 second delay
   time.sleep(1)    
# Make an LED flash off  
   GPIO.output(11,False)
# Set time interval as 1 second delay
   time.sleep(1) 

wifi打印服務器：http://bbs.wenxuecity.com/computer/235417.html 

https://www.adafruit.com/product/4884 硬件也包括arduino等，Pi RP2040類似nano僅12刀，芯片僅1刀，32bit Cortex M+雙核125M@3V3，支持C/C++，Python。板帶264K RAM，8M Flash，21xGPIO，4x12bit ADC,2 I2C/SPI/UART, 16x PWM, 內置0.2A鋰電充，RGB NeoPixel