Quectel EC200UCN MQTT Connection using AWS iot

Technical Subjects Software General Function
1

I am trying to implement MQTT connection with this EC200UCN quectel modem. I am trying to do this by using AT Commands . But i keep receving this output
AT+QFUPL=“UFS:cacert.pem”,1187,100

CONNECT
+QFUPL: 1187,2d19

OK
AT+QFUPL=“UFS:client.pem”,1220,100

CONNECT
+QFUPL: 1220,2e2c

OK
AT+QMTCFG=“recv/mode”,0,0,1

OK

AT+QFUPL=“UFS:user_key.pem”,1675,100

CONNECT
+QFUPL: 1675,7417

OK
AT+QSSLCFG=“cacert”,2,“UFS:cacert.pem”

OK
AT+QSSLCFG=“clientcert”,2,“UFS:client.pem”

OK
AT+QSSLCFG=“clientkey”,2,“UFS:user_key.pem”

OK
AT+QSSLCFG=“seclevel”,2,2

OK
AT+QSSLCFG=“sslversion”,2,4

OK
AT+QSSLCFG=“ciphersuite”,2,0xFFFF

OK
AT+QSSLCFG=“ignorelocaltime”,2,1

OK
AT+QMTOPEN=1,“*************_ats.iot.ap-south-1.amazonaws.com”,8883

OK

+QMTOPEN: 1,0
AT+QMTCONN=1,“test”

OK

+QMTCONN: 1,1

+QMTSTAT: 1,3
I have created a thing on AWS iot and downloaded all of the certifcates .

2
3

In QCOM_V1.6 whenever i open port it closes itself after few seconds why does it do that. This was not happening before . All of a sudden it started behaving like that

4

I too get the same error
AT+QMTCONN=1,“EC200”

OK

+QMTCONN: 1,1

+QMTSTAT: 1,3. Did you solve it ?

5

For the AT+QMTOPEN Commans your repsonse should be 0,0 . If it is not 0,0 then your connection was not opened properly.
You need to start again
Logs :

​

ATI

Quectel
EC200U
Revision: EC200UCNAAR03A11M08

OK
AT+CREG?

+CREG: 0,1

OK
AT+CGREG?

+CGREG: 0,1

OK
AT+CSQ

+CSQ: 31,99

OK
AT+COPS?

+COPS: 0,0,“IND airtel”,7

OK
AT+QICSGP=1,1,“airtelgprs.com”,“”,“”,0

OK
AT+QIACT=1

OK
AT+QIACT?

+QIACT: 1,1,1,“100.87.8.92”

OK
AT+QFUPL=“UFS:root”,1187,100

CONNECT
+QFUPL: 1187,2d19

OK
AT+QFUPL=“UFS:cert”,1224,100

CONNECT
+QFUPL: 1224,5977

OK
AT+QFUPL=“UFS:key”,1675,100

CONNECT
+QFUPL: 1675,526f

OK
AT+QSSLCFG=“cacert”,2,“UFS:root”

OK
AT+QSSLCFG=“clientcert”,2,“UFS:cert”

OK
AT+QSSLCFG=“clientkey”,2,“UFS:key”

OK
AT+QMTCFG=“SSL”,0,1,2

OK
AT+QSSLCFG=“seclevel”,2,2

OK
AT+QSSLCFG=“sslversion”,2,4

OK
​
AT+QSSLCFG=“ignorelocaltime”,2,1

OK
AT+QSSLCFG=“ciphersuite”,2,0xFFFF

OK
AT+QMTCFG=“recv/mode”,0,0,1

OK
​
AT+QMTOPEN=0,“a2wusdljipwadj-ats.iot.ap-south-1.amazonaws.com”,8883

OK

+QMTOPEN: 0,0
AT+QMTCONN=0,“test1”

OK

+QMTCONN: 0,0,0
AT+QMTPUB=0,2,1,1,“testsub”

testing message(press(ctrl+z))

OK

+QMTPUB: 0,2,0
AT+QMTSUB=0,1,“testpub”,0

OK

+QMTSUB: 0,1,0,0

+QMTRECV: 0,0,“testpub”,5,“hello”

Logs for you.

6

Yes, your test was absolutely correct

7

why i am getting this type of ans
[2024-10-02 11:11:26:575_S:] AT+QFUPL=“UFS:Root”,1187
[2024-10-02 11:11:26:634_R:] AT+QFUPL=“UFS:Root.pem”,1187
[2024-10-02 11:11:26:634_R:] CONNECT
[2024-10-02 11:11:28:260_S:] AmazonRootCA1.pem
[2024-10-02 11:11:33:309_R:] +QFUPL: 19,1765

[2024-10-02 11:11:33:309_R:] +CME ERROR: 421

8

Because you are not using the AT+QFUPL command properly you need to put 10 after 1187. What 10 does is it sets the waiting time of respnse to 10 seconds . For 10 seconds the module would wait for the certificate to be uploaded . You also need to do this. Copy my at commands. your root certificate is not being uploaded completely . Because the transmission is being timed out I think . Just copy my AT log.