The Narrowband connectivity is performed with a module from u-blox, the SARA-R410M-02B, a low power chipset operating in the different bands of the IoT LTE cellular range.

Before testing

Key points to check before performing the Sara Module test:

• Make sure that the sim card supports CAT-M1 or NB-IoT and there is enough credit in the sim card.
• Please double check that your sim card is not locked with PUK number. To verify it, insert the sim card in your mobile and unlock it with a PUK number provided by an operator.
• Keep the 4 digit PIN number of your NB-IoT sim card.
• Connect the LiPo battery and an antenna to the NB 1500 board.
• Make sure you have selected the preferred RAT of the SIM card you are using. You can check how to do it here.

Steps

1. Go to File > Examples > MKRNB > Tools > SerialSarapassThrough and upload the sketch.

   

2. Open the Serial monitor and send the following AT commands in the input box and press SEND.

   • AT
   • AT+URAT=7
   • AT+URAT=8

   The output will show an “OK” confirmation which depicts that the “Sara module” is working properly. For the LTE CAT M1 network, set +URAT=7 whereas +URAT=8 for the NB-IoT network only.