SparkFun LTE CAT M1/NB-IoT Shield - SARA-R4 USB AT Commands

Wireless & IoT Cellular
1

Hello - I enabled the VUSB_DET pad. I power up the module by pressing power for approx. 3 seconds. USB connects in Windows 10, I see COM11. I connect TeraTerm or Putty to COM11 @ 115200 baud, no flow control. I see a little character ‘garbage’ draw on the terminal when powering up (usually a good serial port sign!) but, I am unable to enter any commands/characters or get an ‘OK’ message.

Does anyone have any success merely connecting this module to a computer via USB, to use in terminal mode with no Arduino/etc attached? I am unable to get a working prompt/terminal session.

I’ve tried 9600/19200/38400/57600/115200 - all with and with out flow control.

Thank you

2

When you look for a serial port to connect to in TeraTerm, does more than just COM11 show up? When I try I see a debug port and a second serial port. Connecting to the other port at 115200 baud does the trick for me.

For some reason, only the debug port shows up in device manager. I don’t know why the other port won’t display in device manager but will in TeraTerm.

3

Thanks for your message. I see only a single COM port in TeraTerm. There is no other port at all in the drop down menu. I am using a pretty fresh install of Windows 10 on an Intel NUC computer. I’ll try another computer and report back if I have a different result.

4

UPDATE: I tried attaching the module (USB only) to another computer, on this Windows 10 computer, I do see a second COM port and it does respond to AT commands. Many thanks!

5

Glad that you got it working!

I’m still not sure why the extra port doesn’t show up in Windows but if anyone knows, please let us know!

6

It was just this one machine in particular. I believe I know why. I had trouble when first connecting the board using USB - I think the connection (USB) rapidly connected and disconnected due to a bad physical connection and only some of the driver(s) were installed. It’s a guess, but I recall this happening. I tried the same SparkFun board, on another computer (using another USB cable in excellent condition) - it went smoothly. Thank you again