Can't receive SMS using SMSReceive sketch

Just received my MKR NB 1500 board. Tried the SendSMS sketch with my Hologram SIM and it works fine. Tried the ReceiveSMS sketch and it says connected NB Initialized, waiting for messages, however nothing is received.

So I loaded the SerialSARAPassthrough sketch to get the modem version (ATI9) but I get no response on the serial monitor.

How can I get the modem version?

Got the passthrough app to work, need to send NL & CR!

My modem version is L0.,A.02.00. I guess this is not good. Does this explain why I can't receive SMS? Is there a procedure to upgrade the modem without soldering? Perhaps someone shine in with what's required here. Yeez, just bought the module too.

OK, upgraded my modem to L0. I can send SMS, but still not receive.

Does ANYONE have any suggestions on what to do next? Thanks.

You have to downgrade the core to 1.8.9.
In the IDE --> Tools --> Boards --> Board Manager --> SAMD21 Arduino, choose version 1.8.9. Takes a while, don't interupt. Then try again.

@instarep, thanks. That works.

I've developed an application with the MKR 1400 that's been stable for the past couple of years after addressing the power supply issues that the board has. Now it seems that the 3G networks are sunsetting in the US and I'll have to migrate to LTE CAT M1 or NB. Seems like a lot of folks are unhappy with the stability of the MKR NB 1500. In your opinion @instarep, since it appears you have a lot of experience with the board, do you feel that this is a good platform to develop an IoT product?

Also, the SMSReceive seems to be dropping the first character. Anybody else see this?


  • Despite all the loud announcements, network coverage for LTE-M & NBIoT is still poor.
  • I am based in switzerland with (i think) a avarage to good mobile infrastructure. Nevertheless, the LTE-M and NBIoT Bands are not enabled on every antenna and the coverage is poor also from an international perspective. When you check the world coverage maps there is terra incognita all over the caribbean, africa etc.
    Since the SARA 410 on the mkr1500 has no fallback to 2G or 3G it's a problem if you have a mobile device or want to operate in such areas.
  • The mkr1500 has no voice despite LTE-M can do voice.

Ergo: If your application is fixed on a place with a good LTE-M covarage and you don't need voice: yes.

  • The main advantage of LTE-M/NBIoT they say is saving energy and better signal penetration into buildings. If you have no energy saving issues nor coverage its a: No.
  • The mkr1500 is not unstable, the timing and the communication with the modem (which is a complete subsystem) only over the AT console makes it very difficult to write and debug stable code (as also with the mkr1400). The MKRNB library is only a guide to this galaxy and made to demonstrate the tech and the examples.

I wish Arduino will present a MKR1600 with a FULL LTE 5G Modem with voice over I2S and a 2/3G fallback as a worthy successor of the mkr1400!