Raspberry Pi: Memo

since: 2016/09/07
update: 2017/04/11
reference:
1. Omxplayer
2. How To Mount A USB Flash Disk On The Raspberry Pi
3. Playing Audio
4. A security update for Raspbian PIXEL - Raspberry Pi
5. ModMyPi | How to give your Raspberry Pi a Static IP Address

A. omxplayer
     1. 開機時(設定自動登入), 自動播放 loop 影片
         $ cd
         $ sudo nano .bashrc
......
# start omxplayer
echo "tty = $(tty)"

if [ $(tty) == "/dev/tty1" ]; then

  echo "We have a match."
  cd
  omxplayer -o hdmi --no-osd --win 0,0,1920,1080 --loop SenzaPeso.mp4
  #omxplayer -o local --no-osd --win 0,0,1920,1080 --loop SenzaPeso.mp4
  #omxplayer -p -o local --no-osd --win 0,0,1920,1080 --loop SenzaPeso.mp4
  #omxplayer -p -o hdmi --no-osd --win 0,0,1920,1080 --loop SenzaPeso.mp4
  #omxplayer --nativedeinterlace SenzaPeso.mp4

else
  echo "We dont match."
fi

說明: 聲音輸出經由 HDMI: -o hdmi
          聲音輸出經由本地: -o local
          影片格式: 建議 .mp4, .mkv

     2. 強制 HDMI 輸出
         $ sudo nano /boot/config.txt
....
# uncomment to force a HDMI mode rather than DVI. This can make audio work in
# DMT (computer monitor) modes
hdmi_drive=2
....
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B. Mount A USB Flash Disk
$ cd
$ sudo fdisk -l    // you can find some thing like: /dev/sda1
$ sudo mkdir /media/usb
$ sudo chown -R pi:pi /media/usb
$ sudo mount /dev/sda1 /media/usb -o uid=pi,gid=pi

// umount
$ umount /media/usb
-----------------------------------------------------------------------------------------------
 
C. Audio
     1. creating a tone
         $ speaker-test -t sine -f 60 > /dev/null

     2. text to speech
         $ sudo apt-get install espeak
         $ espeak "Hello World" > /dev/null

     3. playing a .wav file
         $ cat ./aplay.sh
#!/bin/bash
while [ 1 ] ; do
aplay oceano.wav
#sleep 5
done
-----------------------------------------------------------------------------------------------
 
D. Enable SSH Login for Raspbian-Pixel      
      => 當將影像檔燒到 SD 卡後, 新增一個 ssh 檔案(內容可以空白或任意),
           將此 ssh 檔案 copy 到 SD 卡根目錄裡(即 boot 下), 接著將 SD 卡放入 Pi 開機.

    備註: To update your existing Jessie image with all the bug fixes and these
              new security changes, type the following at the command line:
              $ sudo apt-get update
              $ sudo apt-get dist-upgrade
              $ sudo apt-get install -y pprompt
-----------------------------------------------------------------------------------------------
 
E. Raspberry Pi: fixed ip address     
     $ sudo cp /etc/dhcpcd.conf /etc/dhcpcd.conf.bak

     $ sudo nano /etc/dhcpcd.conf
interface eth0
static ip_address=192.168.1.2/24
#static routers=192.168.0.1
#static domain_name_servers=192.168.0.1     $ sudo reboot

     $ ifconfig