SARA R4 Unresponsive after initially OK

I'm getting a strange issue after upgrading to the Arduino Support recommended version of A.02.16. The Modem initially starts fine and responds normally, however after approx. 30 seconds it simply stops responding to commands. The only thing I've found to get it to start again is cycling the power. Here's a little snipped from the M-Center logs:

[08:45:52.925] AT+CREG?
[08:45:52.957] 
[08:45:52.957] 
[08:45:52.957] +CREG: 0,2
[08:45:52.957] 
[08:45:52.957] OK
[08:46:27.866] 
[08:46:27.866] AT  // <-- no longer responds
[08:46:28.908] ATE0
[08:46:29.949] AT+CMEE=2
[08:46:30.982] AT+CGMI
[08:46:33.063] AT+CGMM

This is happening on two separate boards. Arduino support have said they only recommend A.02.16 firmware as they believe A.02.21 it has more bugs. Is this a common issue and is there any merit in trying A.02.19 or A.02.21 to address this?

Reset the board by double tapping the reset button and uploading a blink sketch. Afterwards, upload "SerialSARAPassthrough sketch" and set the serial monitor to baud = 115200. Then try again to use AT commmands.

Hi @Dozie, that looks to have helped one of the boards but the other one is still having issues:

[11:51:11.476] +CGREG: 0,4
[11:51:11.476] 
[11:51:11.476] OK
[11:51:11.539] 
[11:51:11.539] AT+CREG?
[11:51:11.555] 
[11:51:11.555] 
[11:51:11.555] +CREG: 0,2
[11:51:11.555] 
[11:51:11.555] OK
[11:51:31.195] 
[11:51:31.195] AT+CCLK?  // <-- Only 20 seconds this time before unresponsive
[11:52:22.234] AT
[11:52:23.272] ATE0
[11:52:24.310] AT+CMEE=2
[11:52:25.339] AT+CGMI
[11:52:27.411] AT+CGMM
[11:52:29.460] ATI0
[11:52:31.520] AT+CGMR

Any other suggestions?

I probably should also mention that this one also refuses to find a MNO profile too:

[11:56:26.667] AT+URAT=8
[11:56:26.682] 
[11:56:26.682] AT+URAT=8
[11:56:26.682] 
[11:56:26.682] OK
[11:56:29.993] 
[11:56:29.993] AT+UMNOPROF=1
[11:56:30.008] 
[11:56:30.008] AT+UMNOPROF=1
[11:56:30.008] 
[11:56:30.008] OK
[11:56:33.221] 
[11:56:33.221] AT+CFUN=15
[11:56:33.253] 
[11:56:33.253] AT+CFUN=15
[11:56:33.253] 
[11:56:33.253] OK
[11:56:37.172] 
[11:56:37.172] AT+UMNOPROF?
[11:56:37.534] 
[11:56:37.534] AT+UMNOPROF?
[11:56:37.534] 
[11:56:37.534] +UMNOPROF: 0

The other board finds 19 Vodafone but this one doesn't with same antenna and SIM.

The trick should work for both. Try repeating it.

Unfortunately, contrary to my earlier reports it's still happening on both, regardless of how many times I install blinky then SerialSARAPassthrough. They both become unresponsive after a short, albeit random, amount of time. I'm inclined to try a newer firmware to see if that fixes the issue.

Hello, did you find the reason of unresponsiveness? I face the same issue after upgrade to the latest firmware (05.12,A.02.21) obtained from ublox.

EDIT: I found that somehow the power saving had been enabled after the firmware update, and that was causing the unresponsiveness modem. I disabled it with m-center and now, albeit I'm facing other issues, is working excellent.

This topic was automatically closed 180 days after the last reply. New replies are no longer allowed.