Paul R. Potts

Member Since: December 6, 2013

Country: United States

  • I am evaluating this module with the development board (not the shield) and I’m running into some trouble.

    I first tried it with a SIM from ReadySim, “30 days talk & text + 2 GB Data.” I first used this SIM in my Android phone and registered it to get a number, and it works fine for SMS and voice calls. The SM5100B will not register on the network with this SIM, no matter what I do. I’ve tried all the bands, and I’ve gone through every option mentioned in these dozens of comments. I always get a status 3 back (“denied.”)

    Today I tried my regular SIM, the one I have used in several different phones for the last few years, which is a T-Mobile SIM. With this SIM the SM5100B seems to register fine on the network. I am not having any success with SMS. Besides just typing AT commands in a serial terminal, I’ve been working with this Java program to talk to the module:

    This seems to work OK up until the point I try to send an SMS. I have successfully sent a couple of short SMS messages but after that the module starts reporting errors. For example, here is the “conversation” with the module (via the tester program, which adds some notes). After I try to send a message all commands start failing:

    ÒÒÒÒÒ +SIND: 1

    +SIND: 10,“SM”,1,“FD”,1,“LD”,1,“MC”,1,“RC”,1,“ME”,1

    +SIND: 11

    +SIND: 3

    +SIND: 4

    (I query with the “get device info” button):

    Spreadtrum Communication CO.,Ltd

    OK Manufacturer : Ò


    OK Model Number : SM5100B-D


    OK Revision : IDH.SC6600D-BASE4_R1.0.0011_B04

    (I query with the “signal strength” button)

    +CSQ: 15,99

    OK Signal level is -83 dbm. Signal condition is good.The signal strength range is -53 dbm (Excellent) to -109 dbm (Marginal).

    (I query with the “SMS support” button)

    +CSMS: 1,1,1,0

    OK Service-> Unkown type Mobile Terminated SMS -> Supported Mobile Originated SMS -> Supported Broadcast type SMS messages -> NOT supported

    (I query with the “SMS SC address” button)

    +CSCA: “+12063130004”,145

    OK SMS service center address is +12063130004

    (I query with the “SMS format” button)

    +CMGF: 0

    OK SMS message for is configured for PDU mode

    (OK, let me try to send a message; phone number blanked out for privacy reasons)

    +CMGF: 0

    OK SMS message for is configured for PDU mode Checking registration status…

    +CREG: 0,5

    OK Device is registered and is roaming.

    Checking SMS Mode…

    +CMGF: 0

    OK SMS message for is configured for PDU mode Checking SMS Mode…

    SMS Service center entry is empty.Not including this field in the PDU

    +CMGS: 40


    I sent a couple of messages successfully, but after that, if I continue to query it, say to ask for my phone number repeatedly, it will work once, then return CME error 4, then error 4 again, then work, then not work, etc. so it seems very unreliable as to whether it will recognize commands. I am talking to it at 9600 baud; I’m using an external 5V power brick that is rated at 2 amps, and the “quad band cellular duck antenna” from Sparkfun.

    Is there a currently available, recommended SIM that is verified to work with this device? I’m in Midland, Michigan, USA. I can use my old personal SIM for experimentation but if we are going to deploy modules like this in projects we will need to set up SIMs for them.

    Is the module just unreliable, in terms of staying up and running?

  • I have done soldering since childhood but have only recently started to experiment with lead-free. It has been frustrating. I’ve been using a Sn/Cu mix from Radio Shack, and had some issues with the higher melting point, and a tendency to carbonize my tips. I got this in the hopes that it would be easier to use. I am not sure what I’m doing wrong, but it is much worse. The flux in this stuff is extremely acrid (much nastier to breathe at the same temperature) as the Radio Shack mix. It flows poorly and wets poorly, forming very high, peaked “beads” on my PCB solder pads. The frozen joints look much worse than the Radio Shack lead-free: they look like cold joints. Worst of all, the flux carbonizes on my iron tip instantly – just one bit, and it has crusty black stains on it and its heat conductivity quickly plummets until after just a few joints it is unusable. That’s starting after a thorough cleaning, and the black gunk is extremely difficult to get off – wet sponge won’t do it, dry sponge won’t do it. I’m really disappointed. I’m experimenting with a temperature-controlled iron at temperatures in the range of about 700-800 F. The Radio Shack lead-free seems to work really well at about 740, allowing me to complete a connection in under ten seconds. This… doesn’t. I’m cranking it up, and lifting pads, with the same iron. Am I supposed to need to douse everything with more flux? I haven’t had to, working on these kits with other lead-free solders.

    I am planning to get myself a new Hakko soldering station after Christmas, and I’ll see if those tips work better, but so far – really disappointed and can’t recommend. What is supposedly “better” about this solder?

No public wish lists :(