BC68 NB-IoT with Arduino UNO

Hello everybody!
I am complete beginner in this matter but had this “work” assigned to me at school. So basically I have BC68 TE-B module and Arduino UNO clone and I have to send AT commands through Arduino to connect to NB-IoT network and send data from a sensor to some kind of API which will write or analyze the data and all of this must be using MQTT protocol.

I am using this library for sending the AT commands https://github.com/thingforward/nbiot-arduino and my problem is that when I send some commands to the Serial they all just print out as a plain text on the monitor and are not “translated” and they do not return any value. image
My teacher suggested that there might be some problems with the pins but I do not know much about that.

What is the problem here? Has anybody some experience with similar topic? Any help is greatly appreciated since I am a complete beginner and I am starting to be kind of lost.

Please download our COM tool:
https://quectel123-my.sharepoint.cn/:u:/g/personal/ae-fae_dom_quectel_com_cn/EZoA_XCCAVBGolMuLeG5K0ABe4OiK9C47QSP81jHsxAw2A?e=ivwY9K
If you still have problems, I recommend that you debug EVB separately first

Hello and thank you for your answer but I think that this COM tool will not really help me to solve my problem. I would need some guidance on how to make Arduino communicate with the BC68 shield so I can send AT commands via code that is uploaded to Arduino.

At present, I think it is mainly due to the matching problem between Arduino and BC68. I suggest you refer to the design manual (no corresponding English manual) for troubleshooting,such as Baudrate etc.
Quectel_BC28_参考设计手册_V1.2.pdf (341.0 KB) Quectel_BC28_硬件设计手册_V1.3.pdf (1.0 MB)

I have gone through these materials and I think there is no problem with the baud rate but my teacher suggested that the problem may be with pin connection or used interface. I found that the main communication is with pins 18 and 17 am I right?

Yes,But you need to connect GND.Can you upload pictures of your development board and BC68?

What pictures do you mean? Like how do I have it connected? I just connected the shield on the Arduino and did not really used any cables or anything.

How do you connect Arduino and BC68 now, please upload your picture?

Unfortunately I can not upload picture now because I have it at school because there is where we have NB-IoT network


This is the only photo I have right now but it is pretty the same but I have antenna connected and both Arduino and the shield are connected to the PC with USB cable and that is it. I have nothing else connected.

Are you testing BC68 TE-B normally so far? If Arduino is no connected.

Yeah I have tested the BC68 TE-B alone and the AT commands work fine. But when I try to send the AT commands via some code through Arduino it does not communicate.

At present, we have not tested the connection and communication between Arduino and module. I suggest you search through Google or other ways. The current investigation may be due to compatibility problems.
Note that Tx\Rx needs to be crossed

One guy suggested that the core to this problem will be the Main UART to USB and Main UART to MCU switch. He said that I should use “to USB” position when uploading project and then switch to "to MCU’ so that the Arduino can send the commands. Could you please explain the purpose or functionality of this switch to me?


In fact, there is no USB in the module pin, and the debug USB you use is only connected to the main URAT port and implemented virtually.

Hey you, I am doing a project also, which is called NB-IoT. I have used BC66 to send relsult from sensor via MQTT protocol. About process with sensor, i used STM32 Nucleo 64 because in document 07-TE-B User_Guide have mentor about it. You can read it again. I have interfaced succedfully between them. Or you can refer here: GSM WITH ARDUINO - AT Commands Step by Step - Smoke Alarmcode - YouTube

Thank you for the recommendation but I have to use Arduino but I have already solved the problem. Thank you very much.

@herbert.pan-Q I am tryin to use bc660 te-b with arduino
how can i use? will i need any library? where can i add board name?
any examples of coding that sends at commands?
@herbert.pan-Q & @Anh_Phuc thanks in advance for the support

I recommend that you debug using TE-B first by AT Command and then with Arduino code

I am able to communicate using AT commands.