Hello guys

@Yassine-Amraue : thank you for explaining that there is a GUI and an API user. I’ve been banging my head trying to send a downlink message via API and always getting an ‘unauthorized’ error. But after registering a callback URL for the API user as well I can now send downlink messages via API to my device. Thanks again.

@magnatron : I am using a SIM7020 based device and previously via API sent downlink messages are getting delivered to it as soon as the device sends an uplink message.

Thanks
Felix

Hello @meneerjacco

what about power saving mode? Maybe that’s enabled by accident?

AT+CPSMS?

Thanks
Felix

Hello @Cees-Meijer

• for me the SIM card provided with the NB-Iot starterkit also worked for LTE-M
• to connect to my own server I used this APN: m2m.public.nl
• I don’t think the dashboard is required when connecting to your own server
• don’t know, but I guess the starterkit is limited to one station independent of the technology (NB-IoT or LTE-M) used

Thanks
Felix

Hello @bb27

as long as no certificate has been downloaded AT+CSETCA? will return an error - that happens for me too.

According to the documentation there is no AT+CSETCA=? (e.g. test) command - so I’d expect an ERROR response.

I am not aware of any specific precondition. Maybe with the exception that it might help to reboot the modem after every failed try to download to have a clean start.

Sorry, at this point in time I am out of ideas.

Thanks
Felix

Hello @bb27

the firmware version on my SIM7020G is 1910B05SIM7020G.

For me the read command AT+CSETCA? only returns OK if at least one certificate has been downloaded successfully. (I use this command to determine whether a specific certificate has already been downloaded or not.)

You probably think of the test command to determine about whether a command exists or not. But test commands typically end in =?.

I found downloading certificates into the SIM7020G is a tricky business and the method is quite different compared to other SIMCOM modems.

Anyhow, hopefully you get some useful information from the manufacturer.

Thanks
Felix

Hello @bb27

what I mean by that is that even after a successful download of the complete certificate when I try to download it again (using the exact same commands) I get an “ERROR”. In other words for me when the certificate has been downloaded fully once (without ERROR) I cannot download it a second time. Only if I dis- and reconnect power I can download the certificate again one time.

Please also note: I am using a SIM7020G which most likely runs different firmware so my advise might not work with your modem version.

Thanks
Felix

Hello @bb27

maybe this post can help you.

Thanks
Felix

Hello @Robert-Heerekop

thank you for that information - this is valuable advise.

Thanks
Felix

Hello @Cees-Meijer

• for me the SIM card provided with the NB-Iot starterkit also worked for LTE-M
• to connect to my own server I used this APN: m2m.public.nl
• I don’t think the dashboard is required when connecting to your own server
• don’t know, but I guess the starterkit is limited to one station independent of the technology (NB-IoT or LTE-M) used

Thanks
Felix

Hello @gerrit-seigers

I don’t own an MKR NB 1500, but from the description here I understand the module supports both LTE-M and NB-IoT.

You write you’d like to use LTE-M. I think in this case you should use a different APN, e.g. m2m.public.nl. See here.

Thanks
Felix

Hello @mario

the pinger error 8 you are seeing means no DNS server have been set.

Looking at the at commands for the SARA-R5 module and the response you posted for the at+cgcontrdp=1 command it looks like ip addresses for primary and secondary DNS are missing.

+CGCONTRDP: 1,5,“iot.telekom.net.MNC040.MCC901.GPRS”,“10.213.137.2.255.0.0.0”,“10.0.0.1”,“”,“”,“”,“”,0,0,1500,0,0

The three IP addresses which are returned are IP, mask and gateway. However the next two entries (primary and secondary DNS) are empty strings.

The only command I’ve seen in the at command list to set DNS ip adress is AT+UPSD. If that is the correct command and how to use it I cannot say as I don’t have that particular modem to test myself.

Hopefully somebody more knowledgeable can help you with that.

Thanks
Felix

Hello @meneerjacco

what about power saving mode? Maybe that’s enabled by accident?

AT+CPSMS?

Thanks
Felix

Hello @Capptn

It’s not very elegant, but it works for me.

The certificate is prepped with \n line endings. The code then counts the lines and replaces the line endings with \\n, then downloads line by line. Each line should yield an OK.

Note: If I try to download the certificate a second time w/o power-cycling the modem, I’ll get an error.

Thanks
Felix

const char myMqttCACert[] = {"\
-----BEGIN CERTIFICATE-----\n\
MIIEAzCCAuugAwIBAgIUBY1hlCGvdj4NhBXkZ/uLUZNILAwwDQYJKoZIhvcNAQEL\n\
BQAwgZAxCzAJBgNVBAYTAkdCMRcwFQYDVQQIDA5Vbml0ZWQgS2luZ2RvbTEOMAwG\n\
A1UEBwwFRGVyYnkxEjAQBgNVBAoMCU1vc3F1aXR0bzELMAkGA1UECwwCQ0ExFjAU\n\
BgNVBAMMDW1vc3F1aXR0by5vcmcxHzAdBgkqhkiG9w0BCQEWEHJvZ2VyQGF0Y2hv\n\
by5vcmcwHhcNMjAwNjA5MTEwNjM5WhcNMzAwNjA3MTEwNjM5WjCBkDELMAkGA1UE\n\
BhMCR0IxFzAVBgNVBAgMDlVuaXRlZCBLaW5nZG9tMQ4wDAYDVQQHDAVEZXJieTES\n\
MBAGA1UECgwJTW9zcXVpdHRvMQswCQYDVQQLDAJDQTEWMBQGA1UEAwwNbW9zcXVp\n\
dHRvLm9yZzEfMB0GCSqGSIb3DQEJARYQcm9nZXJAYXRjaG9vLm9yZzCCASIwDQYJ\n\
KoZIhvcNAQEBBQADggEPADCCAQoCggEBAME0HKmIzfTOwkKLT3THHe+ObdizamPg\n\
UZmD64Tf3zJdNeYGYn4CEXbyP6fy3tWc8S2boW6dzrH8SdFf9uo320GJA9B7U1FW\n\
Te3xda/Lm3JFfaHjkWw7jBwcauQZjpGINHapHRlpiCZsquAthOgxW9SgDgYlGzEA\n\
s06pkEFiMw+qDfLo/sxFKB6vQlFekMeCymjLCbNwPJyqyhFmPWwio/PDMruBTzPH\n\
3cioBnrJWKXc3OjXdLGFJOfj7pP0j/dr2LH72eSvv3PQQFl90CZPFhrCUcRHSSxo\n\
E6yjGOdnz7f6PveLIB574kQORwt8ePn0yidrTC1ictikED3nHYhMUOUCAwEAAaNT\n\
MFEwHQYDVR0OBBYEFPVV6xBUFPiGKDyo5V3+Hbh4N9YSMB8GA1UdIwQYMBaAFPVV\n\
6xBUFPiGKDyo5V3+Hbh4N9YSMA8GA1UdEwEB/wQFMAMBAf8wDQYJKoZIhvcNAQEL\n\
BQADggEBAGa9kS21N70ThM6/Hj9D7mbVxKLBjVWe2TPsGfbl3rEDfZ+OKRZ2j6AC\n\
6r7jb4TZO3dzF2p6dgbrlU71Y/4K0TdzIjRj3cQ3KSm41JvUQ0hZ/c04iGDg/xWf\n\
+pp58nfPAYwuerruPNWmlStWAXf0UTqRtg4hQDWBuUFDJTuWuuBvEXudz74eh/wK\n\
sMwfu1HFvjy5Z0iMDU8PUDepjVolOCue9ashlS4EB5IECdSR2TItnAIiIwimx839\n\
LdUdRudafMu5T5Xma182OC0/u/xRlEm+tvKGGmfFcN0piqVl8OrSPBgIlb+1IKJE\n\
m/XriWr/Cq4h/JfB7NTsezVslgkBaoU=\n\
-----END CERTIFICATE-----\n\
"};

{
  int l = strlen(myMqttCACert);
  int m = 0;
  char line[100];
  int k = 0;

  for(int i = 0; i < l; i++)
  {
    if(myMqttCACert[i] == '\n') m++;
  }
  Serial.println(l);
  Serial.println(m);
  Serial.println(l+m);
  for(int i = 0; i < l; i++)
  {
    char c = myMqttCACert[i];

    if(c != '\n')
    {
      line[k++] = c;
    }
    else
    {
      line[k++] = '\\';
      line[k++] = 'n';
      line[k++] = 0x00;

      Serial2.flush();
      if(strstr(line, "-----END") == NULL)
        Serial2.printf("AT+CSETCA=0,%d,1,0,\"%s\"\r\n", l+m, line);
      else
        Serial2.printf("AT+CSETCA=0,%d,0,0,\"%s\"\r\n", l+m, line);

      delay(10);
      if(Serial2.available())
      {
        Serial.println(Serial2.readString());
      }

      k = 0;
    }
  }
}

Log output:

1452
24
1476
AT+CSETCA=0,1476,1,0,"-----BEGIN CERTIFICATE-----\n"

OK

AT+CSETCA=0,1476,1,0,"MIIEAzCCAuugAwIBAgIUBY1hlCGvdj4NhBXkZ/uLUZNILAwwDQYJKoZIhvcNAQEL\n"

OK

AT+CSETCA=0,1476,1,0,"BQAwgZAxCzAJBgNVBAYTAkdCMRcwFQYDVQQIDA5Vbml0ZWQgS2luZ2RvbTEOMAwG\n"

OK

AT+CSETCA=0,1476,1,0,"A1UEBwwFRGVyYnkxEjAQBgNVBAoMCU1vc3F1aXR0bzELMAkGA1UECwwCQ0ExFjAU\n"

OK

AT+CSETCA=0,1476,1,0,"BgNVBAMMDW1vc3F1aXR0by5vcmcxHzAdBgkqhkiG9w0BCQEWEHJvZ2VyQGF0Y2hv\n"

OK

AT+CSETCA=0,1476,1,0,"by5vcmcwHhcNMjAwNjA5MTEwNjM5WhcNMzAwNjA3MTEwNjM5WjCBkDELMAkGA1UE\n"

OK

AT+CSETCA=0,1476,1,0,"BhMCR0IxFzAVBgNVBAgMDlVuaXRlZCBLaW5nZG9tMQ4wDAYDVQQHDAVEZXJieTES\n"

OK

AT+CSETCA=0,1476,1,0,"MBAGA1UECgwJTW9zcXVpdHRvMQswCQYDVQQLDAJDQTEWMBQGA1UEAwwNbW9zcXVp\n"

OK

AT+CSETCA=0,1476,1,0,"dHRvLm9yZzEfMB0GCSqGSIb3DQEJARYQcm9nZXJAYXRjaG9vLm9yZzCCASIwDQYJ\n"

OK

AT+CSETCA=0,1476,1,0,"KoZIhvcNAQEBBQADggEPADCCAQoCggEBAME0HKmIzfTOwkKLT3THHe+ObdizamPg\n"

OK

AT+CSETCA=0,1476,1,0,"UZmD64Tf3zJdNeYGYn4CEXbyP6fy3tWc8S2boW6dzrH8SdFf9uo320GJA9B7U1FW\n"

OK

AT+CSETCA=0,1476,1,0,"Te3xda/Lm3JFfaHjkWw7jBwcauQZjpGINHapHRlpiCZsquAthOgxW9SgDgYlGzEA\n"

OK

AT+CSETCA=0,1476,1,0,"s06pkEFiMw+qDfLo/sxFKB6vQlFekMeCymjLCbNwPJyqyhFmPWwio/PDMruBTzPH\n"

OK

AT+CSETCA=0,1476,1,0,"3cioBnrJWKXc3OjXdLGFJOfj7pP0j/dr2LH72eSvv3PQQFl90CZPFhrCUcRHSSxo\n"

OK

AT+CSETCA=0,1476,1,0,"E6yjGOdnz7f6PveLIB574kQORwt8ePn0yidrTC1ictikED3nHYhMUOUCAwEAAaNT\n"

OK

AT+CSETCA=0,1476,1,0,"MFEwHQYDVR0OBBYEFPVV6xBUFPiGKDyo5V3+Hbh4N9YSMB8GA1UdIwQYMBaAFPVV\n"

OK

AT+CSETCA=0,1476,1,0,"6xBUFPiGKDyo5V3+Hbh4N9YSMA8GA1UdEwEB/wQFMAMBAf8wDQYJKoZIhvcNAQEL\n"

OK

AT+CSETCA=0,1476,1,0,"BQADggEBAGa9kS21N70ThM6/Hj9D7mbVxKLBjVWe2TPsGfbl3rEDfZ+OKRZ2j6AC\n"

OK

AT+CSETCA=0,1476,1,0,"6r7jb4TZO3dzF2p6dgbrlU71Y/4K0TdzIjRj3cQ3KSm41JvUQ0hZ/c04iGDg/xWf\n"

OK

AT+CSETCA=0,1476,1,0,"+pp58nfPAYwuerruPNWmlStWAXf0UTqRtg4hQDWBuUFDJTuWuuBvEXudz74eh/wK\n"

OK

AT+CSETCA=0,1476,1,0,"sMwfu1HFvjy5Z0iMDU8PUDepjVolOCue9ashlS4EB5IECdSR2TItnAIiIwimx839\n"

OK

AT+CSETCA=0,1476,1,0,"LdUdRudafMu5T5Xma182OC0/u/xRlEm+tvKGGmfFcN0piqVl8OrSPBgIlb+1IKJE\n"

OK

AT+CSETCA=0,1476,1,0,"m/XriWr/Cq4h/JfB7NTsezVslgkBaoU=\n"

OK

AT+CSETCA=0,1476,0,0,"-----END CERTIFICATE-----\n"

OK