I've made a project to send sensor data from
STM32F767ZI
nucleo board
(Client) to a desktop computer (Server), using ethernet and lwip with
FreeRTOS
on
STM32CubeIDE.
The nucleo board is connected with ethernet cable to a wired broadband router, to which the desktop computer is also connected.
In a terminal running under Ubuntu, I am sending a ping message as:
$ sudo ping 192.168.0.3
However, with same code and configurations, the result of ping test is
Destination Host Unreachable
or
64 bytes from 192.168.0.3: icmp_seq=1 ttl=255 time=0.864ms
When the ethernet connection is built successfully, the result of ping test is done correctly and continuously. However, when I try to rebuild the project with the same code and configuration and I use debugging mode, the same ping test fails.
After these findings, I tried to reconnect ethernet in various ways like changing cables, rebooting the board or computer, and reconnecting the debugging port.
Sometimes it works, but then the connection is fails again while I redo the same procedure that worked well before.
What can be wrong about the setup? What should I change?
Related
I'm trying to send UDP packets over the t-mobile NB-IoT network using AT-commands on a SIM7020E chip. I used the product wiki as reference. The starter version of the sim card I have doesn't support TCP, but I'm planning on using that later if I can succesfully communicate using UDP.
I created a UDP-socket on a Raspberry Pi using "nc -u -l 9999". I set an A-record on my hosting provider to refer dev.mydomain.com to the IP address of the Raspberry Pi. I verified the portforward and A-record settings by sending UDP packets from my laptop on another network using "nc -u dev.mydomain.com 9999" and typing some teststrings, so this all works.
On the 4G chip I use the following AT-commands:
// Check network
AT+CSQ
+CSQ: 21,0
AT+CGREG?
+CGREG: 0,5
AT+COPS?
+COPS: 0,2,"20416",9
AT+CGCONTRDP
+CGCONTRDP: 1,5,"iot.t-mobile.nl","x.x.x.x.255.255.255.0" <-- crossed out my ip
// Create UDP socket
AT+CSOC=1,2,1
+CSOC: 0
// Connect socket 0 to the listening port on the Raspberry Pi
AT+CSOCON=0,9999,"dev.mydomain.com"
OK
// Send "test"
AT+CSOSEND=0,0,"test"
At this point I expect to see "test" appear in the command line on the Raspberry Pi, but nothing happens. In the T-mobile portal it shows a PDP-context is successfully activated.
Also, setting the APN manually with AT*MCGDEFCONT="IP","iot.t-mobile.nl","username","password" doesn't work.
Did you work this out Hans? I was plodding along with a SIM7020E following https://www.waveshare.com/wiki/Pico-SIM7020E-NB-IoT code examples. Was successfully sending HTTP GETS to a server (without having to use micropython's wretched urequests lib) via the CHTTPCREATE/CHTTPCON/CHTTPSEND AT cmds, that seem to be be able to send packets over LTE to a server without specifying TCP/UDP etc or using a socket. Maybe give it a try?
Sadly I got the bright idea of trying an 'AT+POWD=1' cmd over the uart (was supposed to power the 7020E down) & now the module now does nothing but echo AT cmds (still auto connects to the LTE network & slow flashes the network led, just won't do anything else.) Real shame, nice little module otherwise.
I have the following connection in Ubuntu
Linux PC -> Switch (PoE) -> DUT
with the following ip configurations:
Ethernet adaptor Statically assigned
BASE IP (ipv4): 10.0.0.1
subnet : 255.255.255.0
gateway : 10.0.0.0
eth0 network address : 10.0.0.3
This setup enables me to send and receive UDP packets.Works perfectly fine in Ubuntu.
Now in Windows, I have made relevant changes to the python code of the codebase, but the code gets stuck waiting for UDP packets from the Hardware. I have statically assigned the same values as in Ubuntu. I am very new to networking..
(1) I have ensured Firewall is allowing UDP packets
(2) I have made the same IP address,subnet,gateway settings configurations.
Where am I going wrong?
It's impossible to say exactly what goes wrong based on this information.
I'd suggest trying Wireshark from https://www.wireshark.org/.
With that running on your windows PC, you can see if your packets are being sent out or not, and you can also see if the device responds or not. That way you can determine if the problem is in sending or receiving the packets.
I am new to Home Assistant and I currently have a disc image of the software installed on a Raspberry Pi 3b. I have managed to get this up and running successfully by connecting my PI to an internet connection via an ethernet cable and connecting my laptop to the same network wirelessly. The problem I am facing is that I wish to run this locally without an internet connection and simply connecting my laptop to the PI with the Ethernet cable does not seem to be working. I have tried looking around for support but I cannot seem to find much on the matter.
Home Assistant's default port is 8123 not 8023.
If there is a direct connection between your laptop and the Raspberry Pi then the chance is high that mDNS won't not work. Thus, homeassistant.local is not reachable.
Add a static IP address for your Home Assistant host and your laptop.
I have a problem with getting GSM connection to work.
Currently used:
Advantech UNO-2272G device
Ubuntu 18.04
NetworkManager/nmcli package
The card works when put in a mobile phone.
*Note: following screenshots are made over SSH and remotely, as the device is currently plugged in ethernet until this issue is resolved.
This is current state of "nmcli" command:
nmcli print
The system connection for GSM is called "radi". My guess is that somehow the interface of that connection is trying to work with the other interface (underlined in red), which in turn is trying to get its DNS conf from router (to which it currently is connected with ethernet, but nothing changes if device is plugged out from router and NetworkManager and network is restarted, it still tries to get to router for its DNS).
This is current state of "ip addr" command:
ip addr
This is current state of /etc/network/interfaces file:
interfaces
This is current state of /etc/NetworkManager/system-connections/radi file:
systemconnection
So, the question is, what am I missing here? Is it the interface issue as written above, or something else entirely?
Disclaimer: I am not that proficient in the stuff presented here, most if not all of it was configured following guidelines on the internet.
Hey I'm not expert in this but I do have a different cellular modem connected to a linux system (RPI) and working with NetworkManager (and ModemManager). My modem was connected by a serial UART port (ttyACM0) so that seems similar to what you have done.
When I configured my cellular connection profile in NM I had to setup the ppp section of the connection profile on top of the gsm part. I also went into my ppp options (on the host) and configured those to match a chat script that came from my modem manufacturer. WHen NetworkManager runs a ppp interface it expects the ppp options for the pppd (daemon) to be configured properly.
Here is the ppp section of my NetworkManager cellular connection settings file. Most are defaults and in my case I only added the baud rate for my modem (since it was connected to a UART).
ppp.noauth: yes
ppp.refuse-eap: no
ppp.refuse-pap: no
ppp.refuse-chap: no
ppp.refuse-mschap: no
ppp.refuse-mschapv2: no
ppp.nobsdcomp: no
ppp.nodeflate: no
ppp.no-vj-comp: no
ppp.require-mppe: no
ppp.require-mppe-128: no
ppp.mppe-stateful: no
ppp.crtscts: no
ppp.baud: 115200
ppp.mru: 0
ppp.mtu: auto
ppp.lcp-echo-failure: 0
ppp.lcp-echo-interval: 0
If this is not helpful then have a look at this thread on NM and routing. In their case eth0 was a local network interface and eth1 was their cellular interface
Now to save you 10 hours of troubleshooting - note that the route
metric is independent of the DNS priority! So if you still have
connectivity issues, make sure it's not a DNS resolution issue (eg.
your DHCP server is providing a dummy resolution service). If it is,
then increase the ipv4.dns-priority of your eth0 connection to make it
lower priority, and/or make sure the ipv4.dns-search of your eth1 is
set to "~" to make it the go-to option.
I am developing a network app for Android and I'm still stuck on connecting my real Android device with an device-emulator running on my desktop computer.
I've created private network with a router, so the only ones connected to the network are my pc and my mobile phone, in order to avoid firewall/closed ports problems.
My PC ip is 192.168.1.100 and I'm trying to ping each other so I can sea reachability of each network node. Ping works fine from my PC (not the emulator console) to the phone.
The problem is that I want to ping the PC-emulator from my mobile phone, not the PC itself... For that, I use the emulator console... Should I use my computer IP or should I use another one? I've seen some ip's like "10.0.x.x" here http://developer.android.com/guide/developing/tools/emulator.html
But I guess those are for connecting two EMULATORS, right?
Besides, I've tried to connect them by socket, creating a redirection for the port via Emulator console, but still can't connect them.
Any clues?
Thanks!!
I tried the early solution I gave you and it didn't work. As you said maybe the reason is the redir command of the emulator console only redirects packets comming from the localhost.
So I searched for a simple proxy server and used it in the same machine to test it out.
http://www.java2s.com/Code/Java/Network-Protocol/Asimpleproxyserver.htm
With this I used the following configuration:
on the proxy:
String host = "localhost";
int remoteport = 3000;
int localport = 4000;
Then run the emulator instance:
Server socket listening on port 2000.
Open telnet instance and issue "redir add tcp:3000:2000"
And finally on the real device open a socket to the machine address on port 4000.
So the network map looks like:
Device <-> machine:4000 Proxy machine:3000 <-> :3000 Emulator :2000 -> Application
This worked for me using the same application on the device and emulator.
I've reached the conclusion that emulator can only receives packets coming from the loopback (127.0.0.1), since when you issue "redir add tcp:port:newPort, it only redirects the first port (associated to the loopback) to the second port (associated to the "emulator virtual ip").
I've tried to create a bridge, which redirects all the packets coming to my pc to the IP 127.0.0.1, but still not works. Thus, I think the emulator has been developed only to communicate with other emulators...
I hope anyone that comes here contradicts me.
You may be able to connect a real device with an emulator instance.
Did you tried setting a redirection on the emulated device and then connect the real device trough a java socket?
For example:
On the emulated device open a server socket listening on port 2000, then open a telnet connection and issue the command:
redir add tcp:4000:2000
Finally, open a socket on the real device to your machine address (192.168.1.100) on port 4000.