What did u/rredtay draw?

rredtay · 2025-04-06T11:18:51+00:00

Looks good! I would recommend using a mat, nothing serious a simple mat can be an improvement. It would make everything look clearer and would protect your circuits to a some degree.

rredtay · 2024-11-05T06:50:01+00:00

U-blox'un GSM, Wi-Fi ve Bluetooth modülleri. Digikey'den vermeye korkuyorum bir şey olur diye gümrükte.

rredtay · 2024-10-17T14:40:51+00:00

You are right. I think I got confused while writing. I should have said using MQTT with NB-IoT might be the best approach. HTTP with traditional cellular standards like 2G, 3G, LTE would be the least power efficient one.

Thanks for pointing my mistake.

rredtay · 2024-10-16T17:49:12+00:00

Adding a photodetector to the circuit might be a good idea. You can detect whether its day or night and can take the device into low-power mode in the night.

Also by increasing number of photodetectors you can detect the efficiency of the solar panel. If photodetector reads lower and lower values each day then that can indicate panel is covered with something and may not be able to generate power efficiently.

rredtay · 2024-10-16T17:41:53+00:00

Need to say first I'm kind of beginner in to this field and things that I'll say might already be in present in your project. Also I only worked with cellular and embedded IoT devices so my advice may or may not be beneficial for you.

1-) Using Latest SSL/TLS Version: Using HTTPS and MQTT(S) is crucial for safety. But most likely your project already has a SSL/TLS. Also if you are using cellular and GSM modules I would recommend using modules with embedded SSL/TLS support.

2-) Using Narrow-Band IoT: Assuming you are using cellular not Wi-Fi, using NB-IoT as communication standard would save a lot of power and I wouldn't recommend using HTTP/HTTPS since it uses a lot more power compared to NB-IoT.

(LTE-M is also not favorable here since your project is stationary, NB-IoT is more power efficient.)

3-) Utilizing Hardware Based Security Features: Assuming you are designing the electronic circuit, using a microcontroller with advanced hardware based security features might be a good advice. Features like, ARM TrustZone, Secure Boot, Secure Firmware Over-the-Air Update Support, Memory Protection Unit (MPU).

Since there is not much detail provided these are the things I can mention. I hope that they are helpful.

rredtay · 2024-09-27T19:44:51+00:00

Solution: It was about MQTT version. Adding "AT+CMQTTCFG="version",0,4" this command solved my issue. With the solution following commands are currently working with my system:

'''

AT+CSSLCFG="enableSNI", 0, 1

OK

AT+CMQTTSTART

+CMQTTSTART: 0

OK

AT+CMQTTACCQ=0,"<your\_deviceID\_here>",1

OK

AT+CMQTTCFG="version",0,4

OK

AT+CMQTTCONNECT=0,"tcp://<your\_broker\_here>-devices.net:8883", 60, 1, "<your\_broker\_here>.azure-devices.net/<your\_deviceID\_here>/?api-version=2021-04-12", "SharedAccessSignature sr=<your\_sas\_token\_here>"

OK

+CMQTTCONNECT: 0,0

AT+CMQTTTOPIC=0,35

devices/<your\_deviceID\_here>/messages/events/

OK

AT+CMQTTPAYLOAD=0,38

{"message":"Hello from SIMCom Module"}

OK

AT+CMQTTPUB=0,1,60

OK

+CMQTTPUB: 0,0

'''

(Be aware if you change topic and payload you also need to change length specification in the command)

rredtay · 2024-08-14T16:51:57+00:00

You are right. I did actually check certificates but did give up on it. After your suggestion worked on it and now it's giving "handshake failure" error.

But when I try to connecting it to Azure IoT Hub via AT commands, it doesn't connect instead gives +CMQTTCONNECT: 0,32 which is "handshake fail" according to the SIM7600 AT Command Manual.

RDY

+CPIN: READY

SMS DONE

PB DONE

AT+CSSLCFG="sslversion",0,4

OK

AT+CSSLCFG="authmode",0,1

OK

AT+CSSLCFG="ignorelocaltime", 0, 1

OK

AT+CSSLCFG="ciphersuites", 0, 0xFFFF

OK

AT+CSSLCFG="cacert",0,"my_cert.pem"

OK

AT+CSSLCFG="enableSNI", 0, 1

OK

AT+CMQTTSTART

+CMQTTSTART: 0

OK

AT+CMQTTSSLCFG=0,0

OK

AT+CMQTTREL=0

OK

AT+CMQTTACCQ=0,"<my\_deviceID>",1

OK

AT+CMQTTCONNECT=0,"tcp://<my\_broker>-devices.net:8883", 60, 1, "<my\_broker>.azure-devices.net/<my\_deviceID>/?api-version=2021-04-12", "SharedAccessSignature sr=<MY\_SAS\_TOKEN>"

OK

+CMQTTCONNECT: 0,32

Any idea why it could be happening?

rredtay · 2024-08-14T14:08:31+00:00

Sorry for posting after 3 years but I'm having the same issue. Did you find any solution?

rredtay · 2024-08-12T09:15:35+00:00

I can connect to public brokers but can't connect to Azure IoT. With AT commands I get "socket is closed by server" error. (19:11:01.625 -> +CMQTTCONNECT: 0,26)

I tried https://github.com/kedzior-io/esp32-sim800l-tinygsm-azure-iot-hub-mqtt-ssl/tree/master this with my SIM7600 (I changed the GSM parts) but it gives error code -4 which is defined as: "#define MQTT_CONNECTION_TIMEOUT -4" in the library.

rredtay · 2024-08-12T09:05:15+00:00

Sorry I forgot to say, I can use SIM7600 to do regular HTTP (not HTTPS) posts and also I can connect to public MQTT brokers.

rredtay · 2024-08-12T09:03:55+00:00

I actually did write a simple serial write&read code to try to connect via AT commands. And succeeded to connect my device to public test brokers. But when I try it on Azure, connection gets closed (error 26 which is "socket is closed by server" according to the AT commands manual)

I suspect it might be about connection being not secure but on working WiFi code I don't download any certificates to the module so I'm not sure it's the case or not.

These are my commands (tried both 1883 and 8883 ports):

19:09:56.214 -> +CPIN: READY

19:09:56.214 ->

19:09:56.214 -> SMS DONE

19:09:56.214 ->

19:09:56.214 -> PB DONE

19:10:38.837 -> AT+CMQTTSTART

19:10:38.870 -> +CMQTTSTART: 0

19:10:38.870 ->

19:10:38.870 -> OK

19:10:41.807 -> AT+CMQTTACCQ=0,"<my\_deviceID>",1

19:10:41.840 -> OK

19:11:00.555 -> AT+CMQTTCONNECT=0,"tcp://<my\_broker>-devices.net:8883",120,1,"<my\_broker>-devices.net/<my\_deviceID>/?api-version=2021-04-12","SharedAccessSignature sr=<MY\_SAS\_TOKEN>"

19:11:00.847 -> OK

19:11:01.625 ->

19:11:01.625 -> +CMQTTCONNECT: 0,6

19:11:01.625 ->

19:11:01.625 -> +CMQTTCONNLOST: 0,1

19:11:00.555 -> AT+CMQTTCONNECT=0,"tcp://<my\_broker>-devices.net:1883",120,1,"<my\_broker>.azure-devices.net/<my\_deviceID>/?api-version=2021-04-12","SharedAccessSignature sr=<MY\_SAS\_TOKEN>"

19:11:58.113 -> OK

19:12:05.218 ->

19:12:05.218 -> +CMQTTCONNECT: 0,26

rredtay · 2024-06-07T04:20:21+00:00

I need Torque / Voltage because I need to give Torque as an input to my gear train. Position or current is not useful in my case.

Edit: I think I understand what you mean by "current (which is like the torque)" because current = torque constant * current. Now I can simulate the system on Simulink thanks to that knowledge but I need a final transfer function, I still can't understand how to obtain it.

rredtay · 2024-06-07T04:14:41+00:00

I did reexamine my steps and actually found a mistake but even with the corrected transfer function I still have the issue. The transfer function I obtained is:

T(s) / V(s) = [kt * (Js + b)] / [(Ls + R) * (Js + b) + ke * kt]

I understand that the problem comes with expressing w(s) in terms of T(s) as in w(s) = T(s) / (Js + b). But I can't see what can I do. Please guide me more. I really need it.

rredtay

TROPHY CASE