MKR NB 1500 Connection Issues

Official Hardware MKR Family MKR NB 1500
1

Hi all,

I am currently trying to get the MKR NB 1500 up and running using LTE-M for a school project. I am using a Hologram Global 3 SIM card and this antenna:
https://www.l-com.com/wireless-antenna-cellular-wifi-multi-band-flexible-fpcb-embedded-antenna

The modem example works fine, and I was able to set my protocol to CAT M1 using the RAT example. I am running into issues using the NBScanNetwork example where I cannot connect to the service. I changed the APN to include "hologram" and these are what my APN commands read:

NB IoT/LTE Cat M1 networks scanner
AT

OK
AT+CPWROFF

OK
AT

OK
AT+CMEE=0

OK
AT+CFUN=0

OK
AT+CPIN?

ERROR
AT+CPIN?

+CPIN: READY

OK
AT+CMGF=1

ERROR
Not connected
AT+CPWROFF

OK
AT

OK
AT+CMEE=0

OK
AT+CFUN=0

OK

I am not sure if it is a software or hardware issue. Also, my SARA module firmware is L0.0.00.00.05.12,A.02.21. Can anyone help me troubleshoot what the problem may be? Thank you!

2

Miraculously, it seems the board is now working. I can see that it is connected to Hologram as well.

Now I have a new issue. I cannot send SMS out. The program says that it was sent, but I am not receiving anything on my phone. I have tried +1 and 001 in front of the number. Anything else it could be?

3

I had similar issues yesterday, seems restart SARA-R410 module (or power cycling the whole board) helped.
As for the SMS I am a little bit clueless at the moment. What does debugging say?

Enabling debug:

NB nbAccess(true);
Elaborating details about SARA-R410 restart

GPRSUdpNtpClient.ino does not start.
Data-SIM only, verified to function with cell phone, PIN code disabled.

Starting Arduino GPRS NTP client.
AT
OK
AT+CMEE=0
OK
AT+CFUN=0
OK
AT+CPIN?
ERROR
AT+CPIN?
ERROR
// ...

With a endless AT+CPIN? ERROR loop, where the NB / Modem is not able to come out of it.
Also tried SIM back to phone, setting PIN code, same result.

TestModem.ino works fine.

Had ChatGPT to make a modified version of SerialSARAPassthrough.ino with some AT commands to get information.

/*
   SerialSARAInfoReader sketch

   This program sends AT commands to the SARA-R410 and retrieves
   useful information about the modem and SIM card at startup.

   Requirements:
   - MKR NB 1500
   - Antenna
   - SIM card

   Make sure the Serial Monitor is set to "Both NL and CR".

   Based on SerialSARAPassthrough by Sandeep Mistry.
*/

// Baud rate for Serial and SerialSARA
unsigned long baud = 115200;

void setup() {
  pinMode(SARA_RESETN, OUTPUT);
  digitalWrite(SARA_RESETN, LOW);

  // Power-on pulse
  pinMode(SARA_PWR_ON, OUTPUT);
  digitalWrite(SARA_PWR_ON, HIGH);
  delay(150);
  digitalWrite(SARA_PWR_ON, LOW);

  Serial.begin(baud);
  while (!Serial);  // Wait until Serial is ready
  SerialSARA.begin(baud);
  delay(1000);

  Serial.println("Starting SARA-R410 Modem Information Retrieval...");
  delay(2000);

  queryModemInfo();
}

void loop() {
  if (Serial.available()) {
    SerialSARA.write(Serial.read());
  }

  if (SerialSARA.available()) {
    Serial.write(SerialSARA.read());
  }
}

void sendATCommand(const char* command, unsigned long timeout) {
  SerialSARA.println(command);
  Serial.print(">> ");
  Serial.println(command);

  unsigned long startTime = millis();
  while (millis() - startTime < timeout) {
    if (SerialSARA.available()) {
      Serial.write(SerialSARA.read());
    }
  }
  Serial.println();
}

void queryModemInfo() {
  Serial.println("Fetching modem and SIM information...");

  sendATCommand("AT+CFUN=15", 2000);  // Full reset
  delay(5000);  // Wait for restart

  sendATCommand("ATI", 2000);           // Module identification
  sendATCommand("AT+GMM", 2000);        // Model name
  sendATCommand("AT+CGMI", 2000);       // Manufacturer
  sendATCommand("AT+CGMR", 2000);       // Firmware version
  sendATCommand("AT+CSQ", 2000);        // Signal strength
  sendATCommand("AT+CREG?", 2000);      // Network registration status
  sendATCommand("AT+COPS?", 2000);      // Current network operator

  sendATCommand("AT+CCID", 2000);       // SIM card ID (ICCID)
  sendATCommand("AT+CIMI", 2000);       // IMSI (International Mobile Subscriber Identity)
  sendATCommand("AT+CPIN?", 2000);      // SIM card status (ready or PIN required)
  sendATCommand("AT+CPIN=xxxx", 2000);      // SIM card status (ready or PIN required)
  sendATCommand("AT+QSPN", 2000);       // Service provider name

  sendATCommand("AT+CGPADDR", 2000);    // Check IP address
  sendATCommand("AT+CGATT?", 2000);     // Check network attachment status
  sendATCommand("AT+UPSND=0,8", 2000);  // Internet connection status
}

Serial Monitor:

Starting SARA-R410 Modem Information Retrieval...
Fetching modem and SIM information...
>> AT+CFUN=15
AT+CFUN=15

OK

>> ATI
ATI

Manufacturer: u-blox
Model: SARA-R410M-02B
Revision: L0.0.00.00.05.12 [Mar 09 2022 17:00:00]
SVN: 09
IMEI: <long number here>

OK

>> AT+GMM
AT+GMM

SARA-R410M-02B

OK

>> AT+CGMI
AT+CGMI

u-blox

OK

>> AT+CGMR
AT+CGMR

L0.0.00.00.05.12 [Mar 09 2022 17:00:00]

OK

>> AT+CSQ
AT+CSQ

+CSQ: 99,99

OK

>> AT+CREG?
AT+CREG?

+CME ERROR: SIM failure

>> AT+COPS?
AT+COPS?

+CME ERROR: SIM failure

>> AT+CCID
AT+CCID

+CCID: <long number here>

OK

>> AT+CIMI
AT+CIMI

+CME ERROR: SIM failure

>> AT+CPIN?
AT+CPIN?

+CPIN: SIM PIN

OK

>> AT+CPIN=xxxx
AT+CPIN=xxxx

OK

>> AT+QSPN
AT+QSPN

ERROR

>> AT+CGPADDR
AT+CGPADDR

+CGPADDR: 1,0.0.0.0

OK

>> AT+CGATT?
AT+CGATT?

+CGATT: 0

OK

>> AT+UPSND=0,8
AT+UPSND=0,8

ERROR

AT command set is defined in 3GPP Technical Standard 27.007

4

I recently had trouble receiving SMS on my MKR NB 1500. I found that clearing the modem memory saved the day. The command that worked for me was AT+CMGD=0,4. See LEXI-R4 and SARA-R4 AT Command Manual for the different flags you can set.

If you include the MKRNB library in your project then you have access to MODEM.

int clear_messages()
{
  String at_response;
  MODEM.send("AT+CMGD=0,4");
  if (MODEM.waitForResponse(5000, &at_response) != 1)
  {
    return 1;
  }
  else
  {
    return 0;
  }
}
1 Like