The Telenor NB-IoT Arduino library

This is a library to make the NB-IoT breakouts from Exploratory Engineering a bit easier to use.

It integrates with the backend service at https://nbiot.engineering/. The sendBytes and sendString functions can be used to send data to remote servers.

Installing the library

Click the green «Clone or Download» button, then «Download ZIP». Add it in the Arduino IDE with Sketch|Library|Add .ZIP library. The library will now be available via Library Manager.

Troubleshooting

If things aren't working as expected, there's a few things you can try out.

Check error code

The errorCode() method returns an error code if the last command failed. If the last command succeeded errorCode() returns -1. The explanation of the error codes can be found in the u-blox N2 AT Commands Manual Appendix A (page 98).

So try to get the error code right after a command has failed to find out why it's failing.

Enable debug mode

The debug mode will print debug statements from the librarary and all commands and responses between the Arduino board and the u-blox N2 module. This is how the Arduino is able to control the module. All the commands are documented in the u-blox N2 AT Commands Manual. Typically you want to look for ERROR responses.

To enable debug mode, add true as the second argument to nbiot.begin(...)

nbiot.begin(ublox, true);

Use a USB-to-serial adapter

If you are having problems getting the module to work you can connect it directly to a serial port or to an USB-to-serial adapter.

First make sure that your module is set up to automatically connect and that the scrambling parameter is set to TRUE:

AT+NCONFIG?

+NCONFIG: "AUTOCONNECT","TRUE"
+NCONFIG: "CR_0354_0338_SCRAMBLING","TRUE"
+NCONFIG: "CR_0859_SI_AVOID","TRUE"
+NCONFIG: "COMBINE_ATTACH","FALSE"
+NCONFIG: "CELL_RESELECTION","FALSE"
+NCONFIG: "ENABLE_BIP","FALSE"

OK

If AUTOCONNECT or CR_0354_0338_SCRAMBLING is set to false you can set it by issuing the following commands which will update the settings and reboot the module:

AT+NCONFIG="AUTOCONNECT","TRUE"
AT+NCONFIG="CR_0354_0338_SCRAMBLING","TRUE"
AT+NRB

These settings will be stored in NVRAM and are kept even when the power is off.

If that looks OK you can check out the radio status by using the AT+NUESTATS command:

AT+NUESTATS

"Signal power",-778
"Total power",-706
"TX power",230
"TX time",28424
"RX time",86269
"Cell ID",16964199
"ECL",0
"SNR",135
"EARFCN",6352
"PCI",6
"RSRQ",-108

OK

If f.e. "TX time" and "RX time" is zero the radio and data should be turned on:

AT+CFUN=1
OK
AT+CGATT=1
OK

Ask on Slack

Other questions? Ask on our NB-IoT Slack Workspace, and someone from our team will try to help.

Missing features

• There's no sanity check on firmware versions. Older versions of the firmware aren't compatible with the library since the AT command syntax is different.
• No support for URCs (aka Unsolicited Response Codes) to detect incomning packets, connectivity change and so on.