I have an LTE CAT M1/NB-IOT shield connected to a Sparkfun Redboard (Arduino Nano) and have followed the tutorial but the shield never connects when I run the 00_Register_Operator example sketch. I have successfully uploaded and run other sketches on this Redboard. The shield is seated properly, the PWR_SEL is set to Arduino, the serial switch is set to HARD (SOFT doesn’t work either), my USB cable is connected to the Redboard, and I have an activated SIM card installed. The serial monitor shows that the Redboard tries to initialize the shield but it never gets to “LTE Shield connected!” even after waiting more than 15 minutes. The shield’s PWR red light is on and the NET blue light comes on about every 20 seconds for a few seconds then turns off.
What am I doing wrong?
It’s the next day and I think I figured it out, sort of. I couldn’t get 00_Register_Operator to work but just for funsies I tried running 01_SMS_Send this afternoon and it worked! I was able to send an SMS to my phone!
I looked at the code and noticed 01_SMS_Send was using pins 8 and 9 so I knew enough to switch the Serial switch on the shield to SOFT. For some reason, I was under the impression that 00_Register_Operator used pins 0 and 1 and so the Serial switch needed to be set to HARD. I actually tried the switch in both positions and neither worked. Once I successfully ran 01_SMS_Send, I could run 00_Register_Operator successfully as long as the Serial switch was set to SOFT even though there was no need to at that point because everything seemed to be working.
Comments in 00_Register_Operator say to comment out the line “SoftwareSerial lteSerial(8, 9);” if you want to use a hardware serial connection (pins 0, 1) but doing so returned an error and the shield never connected to the board. I think my Redboard has a hardware serial connection (pins 0, 1) but I haven’t been successful using those pins. I guess I’ll stick with using pins 8 and 9.
I don’t know why 00_Register_Operator did not work until after I ran 01_SMS_Send. Maybe my SIM card didn’t actually get registered until just before running 01_SMS_Send this afternoon even though my carrier (Ting) said they completed the registration yesterday and the SIM card needs to be working for the shield to connect to the board or maybe running 01_SMS_Send somehow completed the registration. I don’t know enough to know.
So for anyone having the same issues I was having, my advice is to wait a day after setting up your SIM card with your carrier, put your Serial switch in SOFT, and try running 01_SMS_Send.