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..
I'm beginning to learn to code.
Someone said to me: "cURL is the best http client".
To help me understand this sentence, I have two questions:
what is an HTTP CLIENT; and
what is cURL?
I understand you are asking two things:
What is an HTTP CLIENT?
This is any program/application used make communications on the web using the Hypertext Transfer Protocol (HTTP). A common example is a browser.
What is cURL?
This a particular HTTP CLIENT designed to make HTTP communications on the web but built to be used via the command line of a terminal (command prompt).
If you perform a search for these topics, you will easily be able to find more in depth explanations about each.
I want to send HTTP requests to Firebase or Cloudant using AT commands. I'm able to connect to my router and ping to Google:
AT+PING="www.google.com"
+34
OK
For example, in Firebase:
AT+CIPMODE?
+CIPMODE:0
OK
AT+CIPMUX?
+CIPMUX:1
OK
AT+CIPSTART=1,"TCP","https://myapp.firebaseio.com/my_doc.json?mykey",80
ERROR
Or, for Cloudant:
AT+CIPSTART=3,"TCP","https://USERNAME-password#username-bluemix.cloudant.com/estado/doc_estados",8080
ERROR
Is there a way to see what error occurs?
I've seen several examples using Arduino, but I don't want use Arduino.
I am trying to upload data from an Arduino to data.sparkfun.com, but somehow it always fails. To make sure that the HTTP request I am sending is correct, I would like to send it from a computer to the server and see if it uploads the correct values.
According to some examples, the request should be formulated like this:
GET /input/publicKey?private_key=privateKey&dht1_t=24.23&dht1_h=42.4&dht2_t=24.48&dht2_h=41.5&bmp_t=23.3&bmp_p=984021 HTTP/1.1\n
Host: 54.86.132.254\n
Connection: close\n
\n
How do I send this request to the server from my computer? Do I just type in the terminal? Im not sure where to start.
Have a look at curl which should be able to handle your needs.
Even easier and more low level is netcat (here is an example on SO)
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.