nrf9160 (NRF9160-SICA-R) as modem for sending/receiving data by AT Commands

[SilasV]

Hi DevZone! 

I would like to use nrf9160 for sending/receiving data by interfacing it with my microcontroller over UART and sending AT commands. I have a nrf9160 Feather board (check here) which is flashed with the latest modem firmware. I have tested it with CoolTerm (serial terminal app) and it responds with AT Commands. Now I am looking for example set of commands which can help in sending/receiving data over TCP, this will really help a lot! 

Requesting your help/ any pointer

Thanks 

Silas 

[Heidi]

Hi!

I think you are looking for the Serial LTE Modem sample in NCS.

Here is an example of how to establish and test a TCP connection, and send and receive data. 

And here is the documentation for all the supported AT commands for this sample.

Please let me know if you need anything else!

Best regards,

Heid

[SilasV]

Hi Heidi

Thanks for your prompt reply!

I am actually new to using Segger Embedded Studio for nRF Connect. I could build the SLM application in SES and it produced merged.hex output file. How do I also get the .BIN file output which I need to load into the nRF Feather board? Sorry if I am asking a very common question :( 

Thank you so much!

 Silas

[Jared]

Hey Silas,

I wrote up some quick instructions on the subject in the nRF9160 Feather documentation. Hope it helps!

https://docs.jaredwolff.com/nrf9160-serial-lte-modem-sample.html

[Heidi]

Jared's tutorial contains everything you need! Make sure to follow his steps to modify the Serial LTE Modem sample and you should be good to go.

But to answer your specific question (for you and other viewers), to get the .bin file that you, enable bootloader functionality by adding CONFIG_BOOTLOADER_MCUBOOT=y to the "prj.conf" file. 

Then when you build the file you need (app_update.bin) will be located here:

<build_folder>/zephyr/app_update.bin

Best regards,

Heidi

[SilasV]

Hi Jared & Heidi

Thank you so much for your help! The SLM works for me now:)

Now I am trying to send simple data to my Ubuntu server (on DigitalOcean). But not able to get through

Here are the AT commands that I run in CoolTerm

Ready
AT+CFUN=1
OK
AT+CFUN?
+CFUN: 1
OK
AT+CIND=1,0,1
OK
AT+CIND?
+CIND: 1,0,1
OK
AT+CPIN?
+CPIN: READY
OK
AT+CESQ
+CESQ: 99,99,255,255,255,255
OK
AT+CEREG?
+CEREG: 0,4,"FFFE","FFFFFFFF",7
OK
AT+CESQ
+CESQ: 99,99,255,255,255,255
OK
+CIND: "service",1
AT+CESQ
+CESQ: 99,99,255,255,8,29
OK
AT+CEREG?
+CEREG: 0,5,"0936","0C74150F",7
OK
AT+CGDCONT?
+CGDCONT: 0,"IP","hologram","10.117.238.97",0,0
OK
AT#XSOCKET=1,1,0
#XSOCKET: 1, 1, 0, 6
OK
AT#XBIND=1700
OK
at#xtcpconn="138.68.40.173",1700
ERROR

After turning on the nRF to full function, and waiting for sometime, it gets signal strength, but when trying to establish the connection, it gives error.  And on Hologram website, I see that the nRF did get connected, but no data sent.  What is going on? 

Thanks

Silas

 

[Heidi]

Hi!

#XTCPCONN is not an AT command, which is why it's returning an error. Try AT#XCONNECT="138.68.40.173",1700 instead. 

Also AT#XSOCKET=1,1,0 closes a socket. Try AT#XSOCKET=0,1,0 to open a client socket or 0,1,1 to open a server socket. 

Edit due to incorrect documentation: Also AT#XSOCKET=0,1,0 closes a socket. Try AT#XSOCKET=1,1,0 to open a client socket or 1,1,1 to open a server socket. 

[SilasV]

HI Heidi

I got the command #XTCPCONN from this excel (click here) which summarizes all commands. But that could be an older version. 

Further for command AT#SOCKET,  I tried AT#XSOCKET=0,1,0  or  0,1,1  and it always returned error..

Trying AT#XSOCKET=1,1,0 --> always worked (as you can see in the result attached). Further sending this command AT#XCONNECT? also returned +XCONNECT: 1 (which is connected)

but finally it fails when tried to send some data using AT#XSEND="Test TCP"

Would you please help Thank you so much!

Ready
AT+CFUN=1
OK
AT+CIND=1,1,1
OK
AT+CIND?
+CIND: 1,1,1
OK
AT+CPIN?
+CPIN: READY
OK
AT+CESQ
+CESQ: 99,99,255,255,255,255
OK
AT+CESQ
+CESQ: 99,99,255,255,255,255
OK
+CIND: "service",1
+CIND: "roam",1
AT+CESQ
+CESQ: 99,99,255,255,12,33
OK
AT+CEREG?
+CEREG: 0,5,"0936","0C74150F",7
OK
AT+CGDCONT?
+CGDCONT: 0,"IP","hologram","10.117.238.97",0,0
OK
AT#XSOCKET=1,1,0
#XSOCKET: 1, 1, 0, 6
OK
AT#XSOCKET?
#XSOCKET: 1, 6, 0
OK
AT#XBIND=1700
OK
AT#XCONNECT="138.68.40.173",1700
#XSOCKET: -116, closed
ERROR
AT#XSOCKET=1,1,0
#XSOCKET: 1, 1, 0, 6
OK
AT#XSOCKET?
#XSOCKET: 1, 6, 0
OK
AT#XBIND=1700
OK
AT#XCONNECT="138.68.40.173",1700
#XCONNECT: 1
OK
AT#XCONNECT?
+XCONNECT: 1
OK
AT#XSEND="Test TCP"
ERROR
AT#XSOCKET=0
#XSOCKET: 0, closed
OK
AT#XSOCKET=0,1,0
ERROR
AT#XSOCKET=0,1,1
ERROR

[SilasV]

Should I try getting the latest SLM app code from the nRF Connect on GitHub?

[Heidi]

Hi! Sorry about the late reply. I've been testing and seeing the same issues you are seeing, with no solution yet. 

I've been testing the SLM application on the master branch of NCS with no luck so I don't think upgrading will help. 

I know there have been some issues with the SLM application previously, so I will see if anybody has experienced this. 

The comment I made earlier about the #SOCKET command was incorrect, by the way. The documentation is wrong, it's 1 to open and 0 to close. 

Best regards,

Heidi