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Topic: 3G shield send sms (Read 2827 times) previous topic - next topic

AyaTH

I'm trying to use a 3G shield SIM5216A to send SMS message. I wrote a code but it always gives me infinite AT. any suggestions ? or anyone know if there is a library that uses AT commands or any examples.

Thank you.



kjmclark

Ayath, did you get anywhere with this?  Where did you get this example - it has lots of problems, but the approach may be something I'd like to use.

First off, you're using one Serial port to try to talk to both the SIM5216 and your Serial Monitor window.  That most likely won't work.  You need to set your board to talk to a different serial port and use software serial to talk to the board.  Still doesn't work right, but it's probably headed in the right direction.

I've made some changes to your original - still not working, but with two of us beating it up, maybe we'll get somewhere.  Also, check the pin to cycle for your board.  Mine (ITead) used D8 to cycle power, not 2. 

kjmclark

An update.  This page: Jean Britz @ Github, has some great information about using this shield.  One very important caution, however:
for step 6 connecting things in the OPPOSITE ORDER.
Very important!  If you plug into the USB port on the shield before you supply power from somewhere else, the supercapacitor on the shield will attempt to source all of its power through that mini-USB connector.  You *will* fry a trace that way (don't ask me how I know), and will have a very small soldering job to do.

This is the best way I've found to set the baud rate on the board (115200 is too fast for software serial, I stepped it down to 38400) is to do it through the mini-USB connector. 

kjmclark

Also, downloading and installing those drivers was a bit of a pain.  At first, it seemed like windows 7 was rejecting them, but when I installed the drivers one-by-one, it went better.  To do that, save the drivers to a folder somewhere.  Go into device manager, and with that shield first plugged into something else (like your powered arduino), then a USB cable plugged into the USB port on the board, you'll see something like seven new devices that aren't known.  (Seems like they were under ports, but I don't recall now.)  Right-click each one, update the driver, find the files in a local folder, point it to the 64-bit (assuming you're running a 64-bit OS) folder, and let it go. 

That process worked, and I eventually got several new serial ports.  I went with the one that ended in "AT", dug up a terminal emulator app (I used Putty), set it for N81, 115200, no flow control, local echo on, and then reset the board.  I got a perfect start sequence for the modem/board, with no garbled characters.  The command to change the baud rate is "AT+IPREX=38400", or whatever baud rate you want.  You should get an "OK" back.  That sets the default baud rate in the device's flash.

kjmclark

BTW, having spent a good deal of time with this board, I'd recommend people avoid it, and probably ITead in general.  Turns out they had a bug on this board, where they had put wrong resistors in four key places controlling logic-level shifting.  Instead of immediately shipping me corrected boards, they wasted a month of my time giving me the tech-support runaround, insulting me several times even though it turned out to be their bug. 

I've gotten the Adafruit FONA to work, though they were totally rude about it too.  They're making money selling LiPo batteries, and had misleading wording on their website saying the battery *might* be optional.  When I checked, I found lots of people had been snookered by the wording.  When I pointed it out, they finally got around to changing their pages slightly, but aren't proposing to give anyone their money back.  Surprisingly deceptive of Adafruit.

StanleyK

HI,
I bought a Itead 3G board and had some problems. I found another 3G board by Elecfreaks. http://www.elecfreaks.com/estore/3g-shield.html
I got their board to work pretty much the same software as my SIM900 board by Itead. I have had good luck with the SMS functions. It uses a SIM5215E. Comes with a camera too and about the same price. Haven't had a chance to use the camera yet but will do soon.

StanK

carrolte

HI,
I bought a Itead 3G board and had some problems. I found another 3G board by Elecfreaks. http://www.elecfreaks.com/estore/3g-shield.html
I got their board to work pretty much the same software as my SIM900 board by Itead. I have had good luck with the SMS functions. It uses a SIM5215E. Comes with a camera too and about the same price. Haven't had a chance to use the camera yet but will do soon.

StanK
I noticed this board has an SD card slot on it, can you interface it directly from the arduino SPI, or do you have to access it through the SIM5215E?

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