欢快の兔子（joyousrabbit）
树莓派3 uart 大坑
树莓派3的uart默认连接蓝牙了。
解决方法：1.关闭蓝牙，
2.重新配置回uart G14 G15，
3.清楚蓝牙service，
4.重启
Fix is included on manual updates since April 20, and involves adding the following line to /boot/config.txt:
Reboot and the serial connection over GPIO to /dev/ttyAMA0 will be usable.
https://openenergymonitor.org/emon/node/12311
Raspberry Pi 默认有个login程序使用了uart，要关掉。
http://www.hobbytronics.co.uk/raspberry-pi-serial-port
Disable Serial Port Login
To enable the serial port for your own use you need to disable login on the port. There are two files that need to be edited
The first and main one is
This file has the command to enable the login prompt and this needs to be disabled. Edit the file and move to the end of the file. You will see a line similar to
T0:23:respawn:/sbin/getty -L ttyAMA0 115200 vt100
Disable it by adding a # character to the beginning. Save the file.
#T0:23:respawn:/sbin/getty -L ttyAMA0 115200 vt100
When the Raspberry Pi boots up, all the bootup information is sent to the serial port. Disabling this bootup information is optional and you may want to leave this enabled as it is sometimes useful to see what is happening at bootup. If you have a device connected (i.e. Arduino) at bootup, it will receive this information over the serial port, so it is up to you to decide whether this is a problem or not.
You can disable it by editing the file /boot/cmdline.txt
The contents of the file look like this
Remove all references to ttyAMA0 (which is the name of the serial port). The file will now look like this
Reboot
In order you enable the changes you have made, you will need to reboot the Raspberry Pi
解决方法：1.关闭蓝牙，
2.重新配置回uart G14 G15，
3.清楚蓝牙service，
4.重启
Fix is included on manual updates since April 20, and involves adding the following line to /boot/config.txt:
dtoverlay=pi3-miniuart-btReboot and the serial connection over GPIO to /dev/ttyAMA0 will be usable.
https://openenergymonitor.org/emon/node/12311
Raspberry Pi 默认有个login程序使用了uart，要关掉。
http://www.hobbytronics.co.uk/raspberry-pi-serial-port
/etc/inittabWhen the Raspberry Pi boots up, all the bootup information is sent to the serial port. Disabling this bootup information is optional and you may want to leave this enabled as it is sometimes useful to see what is happening at bootup. If you have a device connected (i.e. Arduino) at bootup, it will receive this information over the serial port, so it is up to you to decide whether this is a problem or not.
You can disable it by editing the file /boot/cmdline.txt
The contents of the file look like this
dwc_otg.lpm_enable=0 console=ttyAMA0,115200 kgdboc=ttyAMA0,115200 console=tty1 root=/dev/mmcblk0p2 rootfstype=ext4 elevator=deadline rootwaitRemove all references to ttyAMA0 (which is the name of the serial port). The file will now look like this
dwc_otg.lpm_enable=0 console=tty1 root=/dev/mmcblk0p2 rootfstype=ext4 elevator=deadline rootwaitReboot
In order you enable the changes you have made, you will need to reboot the Raspberry Pi
sudo shutdown -r now