<> Play with raspberry pie ( one ) Basic knowledge 
 Raspberry pie (Raspberry Pi) Is the main run Linux A small computer of the system , You can connect raspberry pie to a TV , monitor , Use of keyboard, mouse and other devices .
 <> one , Differences of raspberry pie models 
 <> two , Peripherals and accessories 
 <>2.1 SD card 
SD Card is a must , Raspberry pie onboard without built-in Flash, Whether it's system boot , still Linux function , Are based on SD Card reading and writing .
 <>2.2 RAM Memory 
 Raspberry pie built-in memory chip , Unable to unplug , Cannot add externally .
 <>2.3  Mouse keyboard 
 Raspberry pie USB Oral 4 individual , So hang a mouse , Another keyboard is more than enough .
 <>2.4 HDMI monitor 
 Raspberry pie is mainly made by HDMI Output to display . But some friends may not find a suitable monitor for a while , Just want to pass HDMI Connect to laptop to display ,but This is not possible .
 
 because HMDI Equipment is divided into HDMI Input and HDMI output , Raspberry pie and laptop belong to HDMI output , Monitors and TVs belong to HDMI input ,HDMI Output connection HDMI Input can be displayed normally , And output to output is nothing .
 <>2.5  Display touch screen 
 Some stores offer 3.5 Inch even 7 Inch display touch screen , It looks small and convenient , Touch operation , But in fact, it is of little use in our actual use .
 *  First, it's from the official website Raspberry Pi OS The system does not support external display touch screen , It doesn't light up when plugged in , Adaptive drive required , Or go to the merchant who buys the touch screen , It's more troublesome .
 * 
 secondly , During our normal use , It's based on raspberry pie Linux Learning and programming , At this time, the mouse and keyboard are more convenient . Look at the code , The bigger the screen, the better . And at this time 3.5 Inches and 7 Inches is too small .
 <>2.6  voice 
 * HDMI Support sound output 
 * 3.5mm  Audio output , Earphones and stereo can be plugged in .
 *  if necessary mic input , You can use USB sound card  
 <>2.7  Power Supply 
 working voltage  5V, adopt micro USB power supply ,  Generally, you need to ensure that there are 3A Current of . And our current mobile phone fast charging head is enough .
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