Problems making a HTTP request with SIMCOM module - http

For the past few weeks, i have been trying to make a HTTP request on a SIMCOM7080. I'm controlling this module via AT Commands. Every path that i try, ends with an ERROR. Does anyone have experience on getting this module to talk with for example Thingspeak? The link that i have tried is this one:
https://prod-162.westeurope.logic.azure.com/workflows/48fcd3ff69634babaa31ef51f89e2051/triggers/manual/paths/invoke?api-version=2016-06-01&sp=%2Ftriggers%2Fmanual%2Frun&sv=1.0&sig=_4eWTUWPLqk5evTp1014kcntXff4akjlFpQJZo_5dFc
The purpose for this is to eventually connect this to an arduino via a UART connection, and displaying data on an IoT device.
Thanks in advance!
Every path with AT commands ends in an error. I have looked up all the documentation given by the manufacturer but it ends with ERROR.

Related

Sim7080G module can't send data over TCP while using GNSS

I bought a Simcom (Sim7080G) module to use it for geolocation and send data over TCP. These modules are quite new on the market (it was first launched in mid 2019) and there is some weird functionning with it. I would like to know if people that use it struggle with the same problem.
My goal is to take GNSS (latitude/longitude) informations, and to send them over TCP.
Activate and take GNSS informations
AT+CGNSPWR=1
returns OK
AT+CGNSINF returns +CGNSINF: 1,1,20200517191239.000,4x.xxxxxx,6.xxxxxx,473.769,0.00,,0,,1.9,2.1,1.0,,7,,7.9,6.0
Connect to any TCP server
AT+CNACT=0,1 returns OK\r\n\r\n+APP PDP: 0,ACTIVE
AT+CAOPEN=0,0,"TCP",151.101.1.69,80 (151.101.1.69 is stackoverflow.com ip address)
--> Some time waiting (like +40s) and then:
+CAOPEN: 0,23\r\n\r\nOK
The code 23 means: 23 Remote refuse, but in my case the connection never reached the server.
Only GNSS or TCP can be used, but not both
What is weird about all of this, is the fact that I can connect on a TCP server, but this stops to work when I activate GNSS.
I sent an email to Simcom technical support.
After insisting that my problem be addressed by a Simcom engineer, I received an answer. I encouraged them to be more clear on their documentation because this information was nowhere (this module is pretty new so I think they missed it on documentation).
Hope to help somebody in the same way or not to do the same pricey error:
Hi Dardan,
"it is not possible to use GNSS and TCP at the same time"
This is known limitation for this module, as there are limitation for
LTE and GNSS part, they can not run simultaneously because they are
sharing part of RF components(SIM7070G low cost version of SIM7000G)
so it is time MUX for LTE and GNSS which means the GNSS performance
could not be good(if customer needs to send GNSS data to server in
very short interval such as <10 seconds), for SIM7000G LTE and GNSS
can work simultaneously without problem. so SIM7070G could be a good
solution for "parcel tracking" etc, which do not need the continue
navigation. please go for SIM7000G, thanks.
xxxx Sun
I found this issue some hours before read this post. My product publishs in AWS IoT MQTT broker; it works, but I need the GPS coordinates to be sent together in message. I'm a lot frustrated, because such problem should be said in Simcom's documents. My previous version was using sim7600g, more expensive, but works fine. I live in Brazil, everytime I need to test some different module I loose more than 1 month to buy from China or somewhere and arrive a new one to me. I tried to turn ON/OFF GNSS and the TCP conection in alternate way, but is too slow the process to reconnect on gsm network.
Ran into this as well. With MQTT it is possible to power down the GPS unit to be able to send and receive MQTT messages without reconnecting/subscribing to the broker again. I've made a 30 second interval to enable/disable the GPS unit and tested it with HiveMQ public broker. Receiving of position data every 60 seconds is possible with this setup, which might be sufficient for some applications. For the price, it has this is still a good module.
I receive no response for HTTP Get request for the http://httpbin.org/get URL. Following is the output using the AT Command Tester from https://m2msupport.net
Checking registration status...
AT+CREG?
+CREG: 2,1,"912","3D73",0
OK
The device is registered in home network.
AT+CGREG?
+CGREG: 2,1,"912","3D73",0,"1"
OK
The device is registered in home network.
Device is registered..
Check the network APN...
AT+CGNAPN
+CGNAPN: 0,""
OK
Network did not send APN to the device.
Activate the network bearer...
AT+CNACT=0,1
OK
+APP PDP: 0,ACTIVE
Set up the HTTP URL...
AT+SHCONF="URL","httpbin.org"
OK
Set up the HTTP body length...
AT+SHCONF="BODYLEN",1024
OK
Set up the HTTP header length...
AT+SHCONF="HEADERLEN",350
OK
Initiating HTTP connection...
AT+SHCONN
OK
Get the HTTP connection state...
AT+SHSTATE?
+SHSTATE: 1
OK
HTTP connection is successful...
HTTP get request...
AT+SHREQ="http://httpbin.org/get",1
OK
No reponse received..

Wireshark Student - I can't see any http post or get requests

I am a student and today for a lab, we were asked to install and use Wireshark. The installation went well, I installed the correct version, installed WinPcap, and the program started without any issues.
I was connected to the University's Wifi and as part of our lab we had to visit http://www.cas.mcmaster.ca/~rzheng/course/CAS4C03W17/Labs/INTRO-wireshark-file1.html and answer questions about the data captured in Wireshark.
Problem is, I am not getting any get or post requests, filtering by http.request.method == "GET" shows nothing, and http.request.method == "POST" shows nothing as well. Filtering by http shows the 200 OK and 304 Not Modified (if I refresh).
I was the only one in my lab who had this problem, and my instructor wasn't able to figure it out. He saved and sent me his output which has Get and Post requests so I can continue my work.
Did anyone have this problem before or have any idea on how to solve it? I can upload the saved outputs if you think it would help. Thanks!
Capture sample looks like it's filtered, since it contains only packets sent to your PC IP address. What is missing:
There is not a single outgoing packet, despite they are obviously on the net. E.g. there are "TCP acknowledge" packets received by PC in capture file, but packets sent by PC, which are acknowledged by them, aren't shown.
Not a single incoming broadcast/multicast packet. This situation is possible, but not very likely.
So there is some trouble with sniffer setup on your site. Possible explanations:
accidentally configured capture filter (don't mix with display filter)
Some interfering software is installed. Example of the same complaint
Method to determine if issue is gone: apply !(ip.dst == YOUR_IP_ADDR) display filter and check if packets output isn't empty on visiting any web page. Possible plan of troubleshooting:
check capture filter
check different network card (e.g. non-wireless connection)
check wireshark operability in pure environment (e.g. liveUSB)
try removing suspected interfering software

sending HTTP requests obtained from WireShark

I have an app controlling my AVR on a local network and I'm trying to embed some of the functionality into another app written by myself. I've started up WireShark and started controlling the volume, which shows up as:
GET /ctrl-int/1/setproperty?dmcp.device-volume=-15.750000 HTTP/1.1
I'm not totally up on this type of http control but i'd like to know if this is enough data to be able to send the same request via a browser or terminal etc.
cheers
Without knowing the avr you can't realy tell. But you should be able to send the command via
avr-ip/ctrl-int/1/setproperty?dmcp.device-volume=-15.750000
in the browser or from you app. The ip should be in the wireshark logs as well.
If that works it was enough information.

Remote server push notification to arduino (Ethernet)

I would want to send a message from the server actively, such as using UDP/TCPIP to a client using an arduino. It is known that this is possible if the user has port forward the specific port to the device on local network. However I wouldn't want to have the user to port forward manually, perhaps using another protocol, will this be possible?
1 Arduino Side
I think the closest you can get to this is opening a connection to the server from the arduino, then use available to wait for the server to stream some data to the arduino. Your code will be polling the open connection, but you are avoiding all the back and forth communications to open and close the connection, passing headers back and forth etc.
2 Server Side
This means the bulk of the work will be on the server side, where you will need to manage open connections so you can instantly write to them when a user triggers some event which requires a message to be pushed to the arduino. How to do this varies a bit depending on what type of server application you are running.
2.1 Node.js "walk-through" of main issues
In Node.js for example, you can res.write() on a connection, without closing it - this should give a similar effect as having an open serial connection to the arduino. That leaves you with the issue of managing the connection - should the server periodically check a database for messages for the arduino? That simply removes one link from the arduino -> server -> database polling link, so we should be able to do better.
We can attach a function triggered by the event of a message being added to the database. Node-orm2 is a database Object Relational Model driver for node.js, and it offers hooks such as afterSave and afterCreate which you can utilize for this type of thing. Depending on your application, you may be better off not using a database at all and simply using javascript objects.
The only remaining issue then, is: once the hook is activated, how do we get the correct connection into scope so we can write to it? Well you can save all the relevant data you have on the request to some global data structure, maybe a dictionary with an arduino ID as index, and in the triggered function you fetch all the data, i.e. the request context and you write to it!
See this blog post for a great example, including node.js code which manages open connections, closing them properly and clearing from memory on timeout etc.
3 Conclusion
I haven't tested this myself - but I plan to since I already have an existing application using arduino and node.js which is currently implemented using normal polling. Hopefully I will get around to it soon and return here with results.
Typically in long-polling (from what I've read) the connection is closed once data is sent back to the client (arduino), although I don't see why this would be necessary. I plan to try keeping the same connection open for multiple messages, only closing after a fixed time interval to re-establish the connection - and I hope to set this interval fairly high, 5-15 minutes maybe.
We use Pubnub to send notifications to a client web browser so a user can know immediately when they have received a "message" and stuff like that. It works great.
This seems to have the same constraints that you are looking at: No static IP, no port forwarding. User can theoretically just plug the thing in...
It looks like Pubnub has an Arduino library:
https://github.com/pubnub/arduino

Why can't I view Omegle's HTTP request/response headers?

I'm trying to write a small program that I can talk to Omegle strangers via command line for school. However I'm having some issues, I'm sure I could solve the problem if I could view the headers sent however if you talk to a stranger on Omegle while Live HTTP Headers (or a similar plug-in or program) is running the headers don't show. Why is this? Are they not sending HTTP headers and using a different protocol instead?
I'm really lost with this, any ideas?
I had success in writing a command line Omegle chat client. However it is hardcoded in C for POSIX and curses.
I'm not sure what exactly your problem is, maybe it's just something with your method of reverse engineering Omegle's protocol. If you want to make a chat client, use a network packet analyzer such as Wireshark (or if you're on a POSIX system I recommend tcpdump), study exactly what data is sent and received during a chat session and have your program emulate what the default web client is doing. Another option is to de-compile/reverse engineer the default web client itself, which would be a more thorough method but more complicated.

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