sim900 signal strength with arduino

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  • Updated 3 years ago
I am trying to get a sim900 module working with my arduino and I got everything setup and I'm able to send AT commands to it, but when I check the signal strenght with AT+CSQ command I get a reading of 0,0. I set the APN and I'm not sure why I don't get a signal. I have an ATT phone and it has a good signal, shouldn't this have about the same? Will I only get a signal once the device is setup properly, or should it always have a signal?
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Wayne Barkmeier

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  • frustrated

Posted 3 years ago

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Vaibhav Mareddy, Official Rep

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Wayne thank you for posting this. 0 refers to signal level of -113dbm or low, can you check the Antenna is connected properly or if possible try with different antenna.
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Wayne Barkmeier

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Thanks for the reply. Are you saying that it should always have a signal? I shouldn't have to program anything on the sim900 to get a signal?
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Bob Heckmann, Official Rep

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Hi Wayne,

Just to confirm:
  • have you referenced Neo's Get Started resources?
  • did you confirm the correct Neo APN is configured in your SIM900 device?
  • what is the physical address where you're looking for coverage?
Regards,
Bob
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Wayne Barkmeier

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Hey Bob,
I have gone through the get started resources several times and confirmed the apn is set correctly, I think. Every apn setting I can set, I set it. Still no signal. I don't understand because i should have good cell coverage. I'm currently in physically located in Windsor CO, but will be returning home to Omaha, NE soon. Both locations should have a strong signal. Can you verify?
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Wayne Barkmeier

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Another thing I noticed is that the AT&T network is forbidden. See below...

AT+COPS=?

+COPS: (3,"AT&T","AT&T","310410"),,(0,1,4),(0,1,2)

Is there another command I have to execute to get it to not be forbidden?

I set the CBAND to:

AT+CBAND?

+CBAND: GSM850_PCS_MODE
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Vaibhav Mareddy, Official Rep

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Wayne,
With the NEO sims we only latch on TMO, so ATT forbidden is ok and the band set is correct one. Can you provide last 4 digits of ICCID that is being used and what is your precise location in windsor,co?
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Wayne Barkmeier

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The ICCID of this sim is 89185015032500230346.

Here's the lat long of where I am.
40.444498, -104.922499
Now I'm seeing this for available networks.
AT+COPS=?

+COPS: (1,"T-Mobile ","T-Mobile ","310260"),(3,"AT&T","AT&T","310410"),,(0,1,4),(0,1,2)

But my signal is still 0
AT+CSQ

+CSQ: 0,0
(Edited)
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Vaibhav Mareddy, Official Rep

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It seems to me as an Antenna issue, you do have good coverage. Try checking if something blocks reception of signal. Was this device working before with any other sims?
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Wayne Barkmeier

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No. I have tried two different sims with no luck. I was thinking the same thing, but I wanted to check to see if there is a setup step I was missing. Do you know, should it show a signal even if it's not connected to an operator?

It must have some sort of signal, otherwise it wouldn't show available networks, correct?
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Vaibhav Mareddy, Official Rep

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Yes, it should be able to detect some signal level.