HDMI
video cable connected to the monitor
2. Serial port
device crack
default, raspberry PI serial port and bluetooth connection.
try to disconnect the bluetooth connection and use the serial port for data communication
a. Watch the start process of raspberry PI, the character
b. serial login raspberry PI
usb-ttl connection raspberry PI serial
1. Please read the instructions carefully connection corresponds to a serial port
the corresponding pins connect to raspberries TXD and RXD (GPIO14 and 15), as shown in figure:
source: https://pinout.xyz/pinout/uart

modify the system configuration, Enable serial login raspberry PI
1. Open the “config.txt” file in the SD kagan directory, add the following to the end and save.

dtoverlay=pi3-miniuart-bt

this stops the bluetooth and removes the use of the serial port.
2. Then change the root directory “cmdlin.txt”, replace all the contents with the following contents, just in case, please backup the original contents of this file first.

dwc_otg.lpm_enable=0 console=tty1 console=serial0,115200 root=/dev/mmcblk0p2 rootfstype=ext4 elevator=deadline fsck.repair=yes rootwait

configuration changes are complete.
default PI
default password: raspberry
3. 1. Let raspberry PI into the network
input command:
sudo nano /etc/wpa_supplicant/wpa_supplicant. Conf

add wireless network configuration information to file :
ctrl_interface=DIR=/var/run/wpa_supplicant GROUP=netdev
update_config=1
country=CN

network = {
ssid = “of your wireless network name”
PSK = “password”
key_mgmt = WPA wpa2-psk
}

network = {
ssid =
“name your other wireless networks” PSK = “password”
key_mgmt = WPA wpa2-psk
}

can set up multiple WIFI information. Press Ctrl+O to write save, Press Enter to confirm, and Ctrl+X to exit.
2. The IP address of the fixed raspberries pie
sudo nano/etc/rc. Local

3. 2.3.3.1 open SSH function
sudo raspi-config
select the fifth option, then select the second option, and OK is completed

if the configuration fails, check the following method:
input command:
sudo raspi-config
select the second option, then select wifi option, then CN CHINA. Enter, then enter the hot spot name, then enter the password, and restart.
sudo apt-get install XRDP (download remote desktop service)
open remote desktop connection, connect XRDP