MKR1400-how do I troubleshoot a POST request?

boriskogan81 · June 21, 2021, 8:11pm

I'm trying to send a POST request to an online server, but failing to connect. How can I troubleshoot/debug the connection?

Code follows:

#include <MKRGSM.h>
#include <ArduinoJson.h>

GSMSSLClient client;

GPRS gprs;

GSM gsmAccess;

// Specify IP address or hostname

char server[] = "webhook.site/ce480c43-95a8-4f1e-b996-bc02f6d1adaa";
int port = 443; // port 443 is the default for HTTPS
DynamicJsonDocument doc(1024);

void setup() {
  bool connected = false;  
  while (!connected) {

  if ((gsmAccess.begin(PINNUMBER) == GSM_READY) &&

       (gprs.attachGPRS(GPRS_APN, GPRS_LOGIN, GPRS_PASSWORD) == GPRS_READY)) {

    connected = true;
    Serial.println("Connected");


   } else {

     Serial.println("Not connected");

     delay(1000);

   }
 }
}
...

  doc["latitude"] = latitude;
  doc["longitude"] = longitude;
  doc["altitude"] = altitude;
  
  String location;
  serializeJson(doc, location);

if (client.connect(server, port)) {
    client.print("POST ");
    client.print("https://");
    client.print(server);
    client.println(" HTTP/1.1");
    client.println("Content-Type: application/json;");
    client.println();
    client.println(location);
  } else {
    // if you didn't get a connection to the server:
    Serial.println("connection failed");
  }

intstarep · June 26, 2021, 4:12am

With

GSM gsmAccess(true);

and then watch the serial monitor.

boriskogan81 · June 27, 2021, 2:48pm

Thank you.

This
This is the output I got on the serial monitor. I'm not sure how to parse it.

I am not seeing a POST request on the webhook site.

Starting Arduino web client.
TAT

OK
AT+IPR=921600

OK
AT

OK
AT+UPSV=3

OK
AT+CPIN?

ERROR
AT+CPIN?

+CPIN: READY

OK
AT+CMGF=1

OK
AT+UDCONF=1,1

OK
AT+CTZU=1

OK
AT+UDTMFD=1,2

AT+CREG?

+CREG: 0,0

OK

+UMWI: 0,1

+UMWI: 0,2

+UMWI: 0,3

+UMWI: 0,4


AT+CREG?

+CREG: 0,0

OK
AT+CREG?

+CREG: 0,5

OK
AT+UCALLSTAT=1

OK
AT+CGATT=1

OK
AT+UPSD=0,1,"prepay.pelion"

OK
AT+UPSD=0,6,3

OK
AT+UPSD=0,2,"arduino"

OK
AT+UPSD=0,3,"arduino"

OK
AT+UPSD=0,7,"0.0.0.0"

OK
AT+UPSDA=0,3

OK
AT+UPSND=0,8

+UPSND: 0,8,1

OK
Connected
AT+USECMNG=0,0,"AddTrust_External_CA_Root",1082
>
+USECMNG: 0,0,"AddTrust_External_CA_Root","1d3554048578b03f42424dbf20730a3f"

OK
AT+USECMNG=0,0,"Baltimore_CyberTrust_Root",891
>
+USECMNG: 0,0,"Baltimore_CyberTrust_Root","acb694a59c17e0d791529bb19706a6e4"

OK
AT+USECMNG=0,0,"COMODO_RSA_Certification_Authority",1500
>
+USECMNG: 0,0,"COMODO_RSA_Certification_Authority","1b31b0714036cc143691adc43efdec18"

OK
AT+USECMNG=0,0,"DST_Root_CA_X3",846
>
+USECMNG: 0,0,"DST_Root_CA_X3","410352dc0ff7501b16f0028eba6f45c5"

OK
AT+USECMNG=0,0,"DigiCert_High_Assurance_EV_Root_CA",969
>
+USECMNG: 0,0,"DigiCert_High_Assurance_EV_Root_CA","d474de575c39b2d39c8583c5c065498a"

OK
AT+USECMNG=0,0,"Entrust_Root_Certification_Authority",1173
>
+USECMNG: 0,0,"Entrust_Root_Certification_Authority","d6a5c3ed5ddd3e00c13d87921f1d3fe4"

OK
AT+USECMNG=0,0,"Equifax_Secure_Certificate_Authority",804
>
+USECMNG: 0,0,"Equifax_Secure_Certificate_Authority","67cb9dc013248a829bb2171ed11becd4"

OK
AT+USECMNG=0,0,"GeoTrust_Global_CA",856
>
+USECMNG: 0,0,"GeoTrust_Global_CA","f775ab29fb514eb7775eff053c998ef5"

OK
AT+USECMNG=0,0,"GeoTrust_Primary_Certification_Authority_G3",1026
>
+USECMNG: 0,0,"GeoTrust_Primary_Certification_Authority_G3","b5e83436c910445848706d2e83d4b805"

OK
AT+USECMNG=0,0,"GlobalSign",958
>
+USECMNG: 0,0,"GlobalSign","9414777e3e5efd8f30bd41b0cfe7d030"

OK
AT+USECMNG=0,0,"Go_Daddy_Root_Certificate_Authority_G2",969
>
+USECMNG: 0,0,"Go_Daddy_Root_Certificate_Authority_G2","803abc22c1e6fb8d9b3b274a321b9a01"

OK
AT+USECMNG=0,0,"VeriSign_Class_3_Public_Primary_Certification_Authority_G5",1239
>
+USECMNG: 0,0,"VeriSign_Class_3_Public_Primary_Certification_Authority_G5","cb17e431673ee209fe455793f30afa1c"

OK
AT+USECMNG=2,0,"AmazonRootCA1"

ERROR
AT+USECMNG=0,0,"Starfield_Services_Root_Certificate_Authority_G2",1011
>
+USECMNG: 0,0,"Starfield_Services_Root_Certificate_Authority_G2","173574af7b611cebf4f93ce2ee40f9a2"

OK
AT+USOCR=6

+USOCR: 0

OK
AT+USOSEC=0,1,0

OK
AT+USECPRF=0,0,1

OK
AT+USOCO=0,"webhook.site",443

ERROR
AT+USOCL=0

ERROR
connection failed

intstarep · June 28, 2021, 4:45am

Welcome to the club! I'm already fighting a long battle on this field of shame...

AT+USOCO=0,"webhook.site",443

Means the modem failed creating a socket to webhook.site on port 443.

ERROR
AT+USOCL=0

The modem answers ERROR...how exciting...
Then tries to close the never opened socket. Answer is ERROR

So, this is the core of the problem. The baseband (the modem) is a seperate "computer" with firmware etc. You can only communicate with AT commands but you can never control or debug whats happening between the modem and the network.

boriskogan81 · June 28, 2021, 3:03pm

I see. Is there anything else that can be done here?

intstarep · July 5, 2021, 3:39am

What all programmers do. Find the bug, don't lose your nerve... Good luck!

zentaizsolt · September 7, 2021, 2:35pm

Hi!

I try to find a working example to post data with mkr1400. A simple get request is working but I can't post data.
I modified this code only to post data:
https://www.hackster.io/smgs/does-the-light-inside-your-fridge-go-off-when-the-door-shuts-6b0de2

Here is my code:

github.com

ZsoZ/Public/blob/main/gsm1400_post.ino

/*
  Web client

 This sketch connects to the Thingspeak website using SSL through a MKR GSM 1400 board. Specifically,
 this example performs a write operation to the thingspeak channel specified in the
 arduino_secrets.h file.
 
 It only performs a write GPRS connection through to Thingspeak when the button is depressed.
 
 You can Change the fields it writes to on Thingspeak as you wish This sketch also prints output to the Serial monitor
 to let you know where it is up to at any given time, lagrely for debugging.

 Other Stuff:
 optional stuff added this sketch currently is the ability to turn an LED on, based on the results of reading a Thingspeak field value.
 A light sensor so that we can read the light value and add that to a Thingspeak field in near realtime and track the lgith throughout the day.

 If the code and the comments disagree, then both are probably wrong. -- Norm Schryer

  Changes:
  04092018 - Added inital code and used the ArduinoJSON libraries

This file has been truncated. show original

Can anybody help me what could be the problem?
(The same post working from postman)

Thanks

This is the serial monitor output:

Starting Arduino web client.
⸮AT

OK
AT+IPR=921600

OK
AT

OK
AT+UPSV=3

OK
AT+CPIN?

ERROR
AT+CPIN?

ERROR
AT+CPIN?

ERROR
AT+CPIN?

ERROR
AT+CPIN?

ERROR
AT+CPIN?

ERROR
AT+CPIN?

ERROR
AT+CPIN?

ERROR
AT+CPIN?

ERROR
AT+CPIN?

ERROR
AT+CPIN?

ERROR
AT+CPIN?

+CPIN: SIM PIN

OK
AT+CPIN="6836"

OK
AT+CMGF=1

OK
AT+UDCONF=1,1

OK
AT+CTZU=1

OK
AT+UDTMFD=1,2

OK
AT+CREG?

+CREG: 0,0

OK
AT+CREG?

+CREG: 0,0

OK
AT+CREG?

+CREG: 0,0

OK
AT+CREG?

+CREG: 0,0

OK
AT+CREG?

+CREG: 0,0

OK
AT+CREG?

+CREG: 0,0

OK
AT+CREG?

+CREG: 0,0

OK
AT+CREG?

+CREG: 0,0

OK
AT+CREG?

+CREG: 0,0

OK
AT+CREG?

+CREG: 0,0

OK
AT+CREG?

+CREG: 0,0

OK
AT+CREG?

+CREG: 0,0

OK
AT+CREG?

+CREG: 0,0

OK
AT+CREG?

+CREG: 0,0

OK
AT+CREG?

+CREG: 0,0

OK
AT+CREG?

+CREG: 0,0

OK
AT+CREG?

+CREG: 0,0

OK
AT+CREG?

+CREG: 0,0

OK
AT+CREG?

+CREG: 0,0

OK
AT+CREG?

+CREG: 0,0

OK
AT+CREG?

+CREG: 0,0

OK
AT+CREG?

+CREG: 0,0

OK
AT+CREG?

+CREG: 0,0

OK
AT+CREG?

+CREG: 0,0

OK
AT+CREG?

+CREG: 0,0

OK
AT+CREG?

+CREG: 0,0

OK
AT+CREG?

+CREG: 0,0

OK
AT+CREG?

+CREG: 0,0

OK
AT+CREG?

+CREG: 0,0

OK
AT+CREG?

+CREG: 0,0

OK
AT+CREG?

+CREG: 0,0

OK
AT+CREG?

+CREG: 0,0

OK
AT+CREG?

+CREG: 0,0

OK
AT+CREG?

+CREG: 0,0

OK
AT+CREG?

+CREG: 0,1

OK
AT+UCALLSTAT=1

OK
AT+CGATT=1

OK
AT+UPSD=0,1,"internet.vodafone.net"

OK
AT+UPSD=0,6,3

OK
AT+UPSD=0,2,""

OK
AT+UPSD=0,3,""

OK
AT+UPSD=0,7,"0.0.0.0"

OK
AT+UPSDA=0,3

OK
AT+UPSND=0,8

+UPSND: 0,8,1

OK
connecting...
AT+CSQ

+CSQ: 25,2

OK
Connecting to HTTP Server...
AT+USECMNG=0,0,"AddTrust_External_CA_Root",1082
>
+USECMNG: 0,0,"AddTrust_External_CA_Root","1d3554048578b03f42424dbf20730a3f"

OK
AT+USECMNG=0,0,"Baltimore_CyberTrust_Root",891
>
+USECMNG: 0,0,"Baltimore_CyberTrust_Root","acb694a59c17e0d791529bb19706a6e4"

OK
AT+USECMNG=0,0,"COMODO_RSA_Certification_Authority",1500
>
+USECMNG: 0,0,"COMODO_RSA_Certification_Authority","1b31b0714036cc143691adc43efdec18"

OK
AT+USECMNG=0,0,"DST_Root_CA_X3",846
>
+USECMNG: 0,0,"DST_Root_CA_X3","410352dc0ff7501b16f0028eba6f45c5"

OK
AT+USECMNG=0,0,"DigiCert_High_Assurance_EV_Root_CA",969
>
+USECMNG: 0,0,"DigiCert_High_Assurance_EV_Root_CA","d474de575c39b2d39c8583c5c065498a"

OK
AT+USECMNG=0,0,"Entrust_Root_Certification_Authority",1173
>
+USECMNG: 0,0,"Entrust_Root_Certification_Authority","d6a5c3ed5ddd3e00c13d87921f1d3fe4"

OK
AT+USECMNG=0,0,"Equifax_Secure_Certificate_Authority",804
>
+USECMNG: 0,0,"Equifax_Secure_Certificate_Authority","67cb9dc013248a829bb2171ed11becd4"

OK
AT+USECMNG=0,0,"GeoTrust_Global_CA",856
>
+USECMNG: 0,0,"GeoTrust_Global_CA","f775ab29fb514eb7775eff053c998ef5"

OK
AT+USECMNG=0,0,"GeoTrust_Primary_Certification_Authority_G3",1026
>
+USECMNG: 0,0,"GeoTrust_Primary_Certification_Authority_G3","b5e83436c910445848706d2e83d4b805"

OK
AT+USECMNG=0,0,"GlobalSign",958
>
+USECMNG: 0,0,"GlobalSign","9414777e3e5efd8f30bd41b0cfe7d030"

OK
AT+USECMNG=0,0,"Go_Daddy_Root_Certificate_Authority_G2",969
>
+USECMNG: 0,0,"Go_Daddy_Root_Certificate_Authority_G2","803abc22c1e6fb8d9b3b274a321b9a01"

OK
AT+USECMNG=0,0,"VeriSign_Class_3_Public_Primary_Certification_Authority_G5",1239
>
+USECMNG: 0,0,"VeriSign_Class_3_Public_Primary_Certification_Authority_G5","cb17e431673ee209fe455793f30afa1c"

OK
AT+USECMNG=2,0,"AmazonRootCA1"

ERROR
AT+USECMNG=0,0,"Starfield_Services_Root_Certificate_Authority_G2",1011
>
+USECMNG: 0,0,"Starfield_Services_Root_Certificate_Authority_G2","173574af7b611cebf4f93ce2ee40f9a2"

OK
AT+USOCR=6

+USOCR: 0

OK
AT+USOSEC=0,1,0

OK
AT+USECPRF=0,0,1

OK
AT+USOCO=0,"api.thingspeak.com",443

OK
Connected!
connected to: 
api.thingspeak.com
443
Beginnning JSON Post Sequence

AT+USOWR=0,5,"504F535420"

+USOWR: 0,5

OK
AT+USOWR=0,21,"2F7570646174652E6A736F6E20485454502F312E31"

+USOWR: 0,21

OK
AT+USOWR=0,2,"0D0A"

+USOWR: 0,2

OK
POST /update.json HTTP/1.1
AT+USOWR=0,24,"486F73743A206170692E7468696E67737065616B2E636F6D"

+USOWR: 0,24

OK
AT+USOWR=0,2,"0D0A"

+USOWR: 0,2

OK
Host: api.thingspeak.com
AT+USOWR=0,53,"557365722D4167656E743A206D772E646F632E62756C6B2D757064617465202841726475696E6F204D4B522047534D203134303029"

+USOWR: 0,53

OK
AT+USOWR=0,2,"0D0A"

+USOWR: 0,2

OK
User-Agent: mw.doc.bulk-update (Arduino MKR GSM 1400)
AT+USOWR=0,17,"436F6E6E656374696F6E3A20636C6F7365"

+USOWR: 0,17

OK
AT+USOWR=0,2,"0D0A"

+USOWR: 0,2

OK
Connection: close
AT+USOWR=0,30,"436F6E74656E742D547970653A206170706C69636174696F6E2F6A736F6E"

+USOWR: 0,30

OK
AT+USOWR=0,2,"0D0A"

+USOWR: 0,2

OK
Content-Type: application/json
AT+USOWR=0,16,"436F6E74656E742D4C656E6774683A20"

+USOWR: 0,16

OK
Content-Length: AT+USOWR=0,3,"313236"

+USOWR: 0,3

OK
AT+USOWR=0,2,"0D0A"

+USOWR: 0,2

OK
126
AT+USOWR=0,2,"0D0A"

+USOWR: 0,2

OK

{"api_key":"1231231231321","field1":"32","latitude":"","longitude":"","status":"Arduino Test: "}AT+USOWR=0,1,"7B"

+USOWR: 0,1

OK
AT+USOWR=0,1,"22"

+USOWR: 0,1

OK
AT+USOWR=0,1,"61"

+USOWR: 0,1

OK
AT+USOWR=0,1,"70"

+USOWR: 0,1

OK
AT+USOWR=0,1,"69"

+USOWR: 0,1

OK
AT+USOWR=0,1,"5F"

+USOWR: 0,1

OK
AT+USOWR=0,1,"6B"

+USOWR: 0,1

OK
AT+USOWR=0,1,"65"

+USOWR: 0,1

OK
AT+USOWR=0,1,"79"

+USOWR: 0,1

OK
AT+USOWR=0,1,"22"

+USOWR: 0,1

OK
AT+USOWR=0,1,"3A"

+USOWR: 0,1

OK
AT+USOWR=0,1,"22"

+USOWR: 0,1

OK
AT+USOWR=0,1,"34"

+USOWR: 0,1

OK
AT+USOWR=0,1,"31"

+USOWR: 0,1

OK
AT+USOWR=0,1,"56"

+USOWR: 0,1

OK
AT+USOWR=0,1,"4C"

+USOWR: 0,1

OK
AT+USOWR=0,1,"39"

+USOWR: 0,1

OK
AT+USOWR=0,1,"39"

+USOWR: 0,1

OK
AT+USOWR=0,1,"35"

+USOWR: 0,1

OK
AT+USOWR=0,1,"41"

+USOWR: 0,1

OK
AT+USOWR=0,1,"59"

+USOWR: 0,1

OK
AT+USOWR=0,1,"4D"

+USOWR: 0,1

OK
AT+USOWR=0,1,"38"

+USOWR: 0,1

OK
AT+USOWR=0,1,"30"

+USOWR: 0,1

OK
AT+USOWR=0,1,"53"

+USOWR: 0,1

OK
AT+USOWR=0,1,"34"

+USOWR: 0,1

OK
AT+USOWR=0,1,"39"

+USOWR: 0,1

OK
AT+USOWR=0,1,"50"

+USOWR: 0,1

OK
AT+USOWR=0,1,"22"

+USOWR: 0,1

OK
AT+USOWR=0,1,"2C"

+USOWR: 0,1

OK
AT+USOWR=0,1,"22"

+USOWR: 0,1

OK
AT+USOWR=0,1,"66"

+USOWR: 0,1

OK
AT+USOWR=0,1,"69"

+USOWR: 0,1

OK
AT+USOWR=0,1,"65"

+USOWR: 0,1

OK
AT+USOWR=0,1,"6C"

+USOWR: 0,1

OK
AT+USOWR=0,1,"64"

+USOWR: 0,1

OK
AT+USOWR=0,1,"31"

+USOWR: 0,1

OK
AT+USOWR=0,1,"22"

+USOWR: 0,1

OK
AT+USOWR=0,1,"3A"

+USOWR: 0,1

OK
AT+USOWR=0,1,"22"

+USOWR: 0,1

OK
AT+USOWR=0,1,"33"

+USOWR: 0,1

OK
AT+USOWR=0,1,"32"

+USOWR: 0,1

OK
AT+USOWR=0,1,"22"

+USOWR: 0,1

OK
AT+USOWR=0,1,"2C"

+USOWR: 0,1

OK
AT+USOWR=0,1,"22"

+USOWR: 0,1

OK
AT+USOWR=0,1,"6C"

+USOWR: 0,1

OK
AT+USOWR=0,1,"61"

+USOWR: 0,1

OK
AT+USOWR=0,1,"74"

+USOWR: 0,1

OK
AT+USOWR=0,1,"69"

+USOWR: 0,1

OK
AT+USOWR=0,1,"74"

+USOWR: 0,1

OK
AT+USOWR=0,1,"75"

+USOWR: 0,1

OK
AT+USOWR=0,1,"64"

+USOWR: 0,1

OK
AT+USOWR=0,1,"65"

+USOWR: 0,1

OK
AT+USOWR=0,1,"22"

+USOWR: 0,1

OK
AT+USOWR=0,1,"3A"

+USOWR: 0,1

OK
AT+USOWR=0,1,"22"

+USOWR: 0,1

OK
AT+USOWR=0,1,"22"

+USOWR: 0,1

OK
AT+USOWR=0,1,"2C"

+USOWR: 0,1

OK
AT+USOWR=0,1,"22"

+USOWR: 0,1

OK
AT+USOWR=0,1,"6C"

+USOWR: 0,1

OK
AT+USOWR=0,1,"6F"

+USOWR: 0,1

OK
AT+USOWR=0,1,"6E"

+USOWR: 0,1

OK
AT+USOWR=0,1,"67"

+USOWR: 0,1

OK
AT+USOWR=0,1,"69"

+USOWR: 0,1

OK
AT+USOWR=0,1,"74"

+USOWR: 0,1

OK
AT+USOWR=0,1,"75"

+USOWR: 0,1

OK
AT+USOWR=0,1,"64"

+USOWR: 0,1

OK
AT+USOWR=0,1,"65"

+USOWR: 0,1

OK
AT+USOWR=0,1,"22"

+USOWR: 0,1

OK
AT+USOWR=0,1,"3A"

+USOWR: 0,1

OK
AT+USOWR=0,1,"22"

+USOWR: 0,1

OK
AT+USOWR=0,1,"22"

+USOWR: 0,1

OK
AT+USOWR=0,1,"2C"

+USOWR: 0,1

OK
AT+USOWR=0,1,"22"

+USOWR: 0,1

OK
AT+USOWR=0,1,"73"

+USOWR: 0,1

OK
AT+USOWR=0,1,"74"

+USOWR: 0,1

OK
AT+USOWR=0,1,"61"

+USOWR: 0,1

OK
AT+USOWR=0,1,"74"

+USOWR: 0,1

OK
AT+USOWR=0,1,"75"

+USOWR: 0,1

OK
AT+USOWR=0,1,"73"

+USOWR: 0,1

OK
AT+USOWR=0,1,"22"

+USOWR: 0,1

OK
AT+USOWR=0,1,"3A"

+USOWR: 0,1

OK
AT+USOWR=0,1,"22"

+USOWR: 0,1

OK
AT+USOWR=0,1,"41"

+USOWR: 0,1

OK

intstarep · September 7, 2021, 6:40pm

Why do you want to use the http protocol?
I think the mqtt protocol is much more suitable.

zentaizsolt · September 7, 2021, 7:40pm

Thanks. I am not familiar with mqtt protocol. The final target to write the data to my database. Thingspeak just an exapmle to test post. At the end i would call my own web api to store data.
If i use mqtt i need an MQTT Broker if I am right.

Idahowalker · September 7, 2021, 7:50pm

One could use words like "arduino mqtt broker" and find many public MQTT Brokers available.

intstarep · September 8, 2021, 5:46am

There are some advantages with small data amounts (persistent socket, less overhead etc) and you can provide the data to many endpoints, because the "server" is a broadcaster called broker.
Read some introductions and you will get it.
Yes, you are right, a mqtt broker (server) is needed, there are public ones (also with a web interface to debug and visualize( shiftr.io for example). I run a broker called mosquitto and wrote a node.js that acts as a receiver (listener) of the broadcast and writes the data in a database.
On the arduino site, as mentioned, you need a library (i use GitHub - 256dpi/arduino-mqtt: MQTT library for Arduino) but there are others.
The SARA410 modem on the mkr1500 has also a internal mqtt functionality, i started a lib under
GitHub - CptHolzschnauz/MKRNB: NBMQTT is a new class for the MKRNB library to use the internal MQTT functionality of the SARA R410 modem (my other name is cpt. holzschnauz ;=)
It's under construction, you can connect, send etc. but receiving data from the broker is not yet implemented (everyone is welcome to contribute!)

You can also stay with the http and find a POST solution or, maybe simpler, do a get request (like the example) with the data (example: blabla.html?data=helloworld ) and parse on the server.

zentaizsolt · September 9, 2021, 8:37pm

Thanks instarep! It works fine with mqtt. I installed a mosquitto broker too.

system · January 7, 2022, 8:37pm

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