SIM900B vs SIM300 - Anyone used SIM900B successfully, without major headaches

[jayachar88]

Hi Folks,

Have a prototype working reasonably with SIM300, but have been told that SIM300 is an obsolete product and that I should move to SIM900B. On researching here a bit, I found that people have reported lots of problems with SIM900B, while making the move from SIM300. The problems reported are like -

1) SIM not detected
2) Unable to register to network
3) Module power-down immediately after registration to network
4) Unable to send SMS (although receiving SMS seems to work)

and each of these problems seem to have been reported by multiple people. Wondering if anyone here has cracked it, and has got SIM900B working.

My requirements are -
a) Send / receive SMS
b) Send / receive USSD
c) Establish data connection via GPRS / EDGE
d) Send / receive voice calls

Folks who have it working well, if you have had to apply some tricks / caveats then kindly do share.

Thanks,
Jay

 

[jayachar88]

Well, found something and thought of sharing. Looks like most of the headaches and rear-pains can be prevented by reading, rather well-documented data-sheets, app-notes.
I am guessing that most people felt pain when they assumed SIM900X series to be a "drop-in" replacement for SIM300X series, which it is not, even if the brochure / website seems to allude to that possibility. Read it as "replacement", not exactly "drop-in replacement". There are enough differences in the B2B connector, electrical differences in voltage thresholds/max's, and AT command set, startup string, to warrant a thorough read of the specs.

Anyway, I am trying to order some SIM900's as they don't seem to be as easily available in retail, as the SIM300's and will test this further and report back.

In the meantime, if anyone knows where SIM900A and SIM900S can be purchased in Bangalore, India - would appreciate if you please let me know. Currently tried all usual routes, but stock of those 2 models / parts, seem to be elusive.