GSM Module Selection

JAM2014 · Joined: 24 Apr 2014 Posts: 138

Hi All,

I've been using the Simcom SIM900 GSM module for a number of years for a SMS based remote control and telemetry system. Recently, however, a number of cellular carriers here in the US have obsoleted 2G service, and these modules no longer work. As I expect this trend to continue, I'm looking for a more modern (3G/LTE) solution to replace the SIM900, and I'm considering at the Simcom SIM7100C. Does anyone have any experience with this module, or another to recommend? Although this product will ultimately be assembled professionally, a module that can be hand soldered, or is available on a breakout board, is attractive for prototyping purposes.

Thanks,

Jack

newguy · Joined: 24 Jun 2004 Posts: 1909

Regarding the hand soldered aspect for prototyping, consider buying solder paste and a hot air "pencil" such as:

http://www.ebay.com/itm/2-in-1-Soldering-Rework-Stations-SMD-Hot-Air-Iron-Gun-Desoldering-Welder-852D-/181139781537

$45 for a 2 in 1 hot air/conventional soldering station...you really can't go wrong for that. Search ebay for "hot air smd" and there are literally hundreds of options. You can get syringes of solder paste from Digi-Key overnight. Just store them in the fridge.

You can also get a cheap "easy bake" reflow oven for doing prototypes:

http://www.ebay.com/itm/T962-Infrared-SMD-BGA-IC-Heater-Reflow-Oven-18X23-5CM/172244074087?_trkparms=aid%3D555019%26algo%3DPL.BANDIT%26ao%3D1%26asc%3D46673%26meid%3Da1bd6e6f6e15457ea87a2b1f4d2ec4c0%26pid%3D100506%26rk%3D1%26rkt%3D1%26&_trksid=p2045573.c100506.m3226

I have experience with this model, and it's quite invaluable.

What I'm trying to convey is that don't let a part's "conventional solderability" influence your choice. I'm 3 months into a new position where past choices for some things were based on hand solderability for prototypes. First thing I did was bring in a hot air pencil similar to the one above and the same "easy bake" oven above. By hand I can (almost comfortably) solder a 40 pin + exposed pad 5x5mm QFN part pretty reliably.

At the moment we're rather stuck with a particular RF module which is large, expensive, but hand solderable. Functionally equivalent modules which are a fraction of the size (and cost!) are available, but were dismissed at the time because they couldn't solder them by hand.

Ttelmah · Joined: 11 Mar 2010 Posts: 19552

Use the SIM900A, or the SIM900F....

That's the whole point of the difference. The A is the quad band unit, and the F is the 4G version

Gabriel · Joined: 03 Aug 2009 Posts: 1067 Location: Panama

I've had great experiences with telit and quectel modules from Mikroe.com

I must have 30+ of these deployed.

Edit: obvious but necessary disclaimer... no i do not work nor sell for mikroe....same relationship i have with ccs... it works.

G.
_________________
CCS PCM 5.078 & CCS PCH 5.093

Ttelmah · Joined: 11 Mar 2010 Posts: 19552

Key though is that if he has a working code-base for the SIM900, this will run with only minor tweaks on the newer version of this.

I've been this way, and have a library I wrote about five years ago on the SIM900A (needed the quad band), and have since transferred to the 'F'.

JAM2014 · Joined: 24 Apr 2014 Posts: 138

JAM2014 · Joined: 24 Apr 2014 Posts: 138

Ttelmah · Joined: 11 Mar 2010 Posts: 19552

The reason is that the F is a plug replacement for the older module.

Same PCB layout, and 99% runs the same commands.

They just have notes to look at the SIM900 data for it!...

If you look on the SIMCOM site for SIM900 4G, it should take you to this, otherwise you'll need to talk to one of their agents.

It depends how fast you want to go. It only gives class 10 (85600bps).

If you talk to your suppliers, you may well even be getting the 4G version now.

soonc · Joined: 03 Dec 2013 Posts: 215

benoitstjean · Posted: Sat Oct 07, 2017 6:50 am

You can also try the SIM5320A but it's 3G only. Single chip solution, includes a GPS engine (L1 frequency). The internal guts is a QualComm chipset.

To get the documentation, go to http://simcomm2m.com/En/ and you must register.

The global sales network is found at http://simcomm2m.com/En/service/.

Anyhow, been using the SIM5320A for 5 years and it's a great device.

The downside is that the documentation is not great because it's written in very poor english by non-english people. Some sectoions lack information, like netowkr errors and such therefore when the modem returns an error, it's difficult to figure-out what happened.

But, all in all, it is an awesome device once you get it to work and iron-out all the undocumented details.

There is a newer version which is LTE and is pin-to-pin compatible with the 5320 except for a few pins.

If you're wondering, the letter at the end of the modem is for the region: e.g. A is for North-America, J/E is for like Australia and NZ but this is all written in their documentation.

It's also pretty cheap in price.

Ben