Question 1 SSH login RM60 error message: no matching host key type found. Their offer: ssh-rsa,
Reason: New version of openssh or login ssh-client (RSA encryption method is not applicable by default).
Temporary solution: ssh -oHostKeyAlgorithms=+ssh-rsa [email protected] Temporary
Permanent solution: sudo vim ~/.ssh/config ##The actual path is /etc/ssh/config
Add the following:
Host *
PubkeyAcceptedKeyTypes +ssh-rsa
HostKeyAlgorithms +ssh-rsa
Question 2: Changing the fixed IP address on mlu220 has no effect after restarting the system.
Reason: The mlu220-som module starts without mounting the real hard disk by default. All modifications to the startup module are completed in memory. When the system restarts, the settings in emmc will be reloaded into memory.
Solution: Use the serial port to enter the mlu220 module. The root password for the account is Hello123; after entering, use the following command
mount -t ext4 -o sync /dev/mmcblk0.boot /boot #Use the blkid command to obtain /boot information.
vi /boot/uenv_extra.txt
Modify or add the following content (fill in the IP as needed):
ipaddr=192.168.16.101
#serverip=192.168.16.254
netmask=255.255.255.0
gatewayip=192.168.16.254
#ethaddr=b2:63:9e:e2:92:00
Reboot after exiting editing;
Question 3: The 5G module sometimes cannot access the Internet
Reason: 5G modules are divided into full Netcom, and the 5G module of the castrated version of Qualcomm chip can only be one of China Unicom, China Mobile, and China Telecom. The castrated version can only use SIM cards supported by the module. The antennas of the 5G module are set, usually one pair (the module we selected), and each antenna interface has its own definition. For example, Quectel module
Solution: The antenna should be 0 and 3 as a pair. 1 and 2 are a pair of antennas. (Some cards need to use LTE to communicate with mobile base stations to access the Internet) So it is recommended to use a 0.3 antenna.
If it is a castrated version of the 5G module, make sure it is the IoT SIM card specified by the module (what a painful realization).
Question 4 There is a wifi signal and cannot be connected. Or there may be various strange problems, but if all the antennas are connected, it will be normal.
Reason: There are many kinds of wifi modules, and the better performance is to choose mimo (two antennas, one sent and received) and the same antenna to receive and send at the same time (can it be understood as half-duplex?). The module we chose is mimo (very powerful).
Solution: Wi-Fi antennas must be connected one-to-one. For example, we choose Hilink's RM60 module. Among them, the 2.4G antenna and the 5G antenna must be installed in two when installing the antenna (both are installed in the same frequency band).
Question 5: When switching the Internet network card or port, pinging baidu.com fails. (But you can access the Internet when confirming the routing)
Reason: When switching ports, the router cannot automatically switch to the Internet port. For example, a router A was connected to the network port A. Now I unplug the network cable and connect it to the USB network port to connect to the Internet. The system does not automatically switch routes.
Solution: Use the ip link show command to get the name of your replacement network card (for example, esp1n0), and use the command udhcp -i esp1n0.
Question 6 How to set the APN of the IoT card (the SIM card can also be automatically recognized for Internet access by default)
Reason: APN determines the method and network through which the mobile phone is connected. Some SIM card networks require manual settings to take effect.
Solution: Enter the routing login interface luci interface, enter network (network)-》interface (interface)-》5G edit interface
Fill in the APN pin code provided by your sim card provider. It is usually written on your sim (not opened). Just fill it out and save it.