Sim900a mini - Page 1
Forum section: electronics / beginners

author: 0x007
author_rank: Contributor
timestamp: April 15, 2015, 08:19:38 pm
content: Hello good people of EEVblog Forum, and this is my first post.Me and my class mates are working now on our graduation project , 8051 and stuff...one of my friends decided to work with " Sin900a mini " modulenow the problem : no one of us have any clue about how to make this thing work.we looked for data sheets but nothing was found about the module (not the sim900 circuit),Prof Google and Prof Youtube were not much help either.So did anyone ever worked with this module ?I have to know so I could ask specific questions.any comment will be appreciated

author: 128er
author_rank: Regular Contributor
timestamp: April 15, 2015, 08:33:02 pm
content: Hi and welcome to the Forum,on the following pages you can find some useful informations like hardware descriptions and AT-commands.Never used this module before. That was only a quick google search. Make sure the informations fits to your module.http://www.simcom.us/product_detail.php?cid=1&pid=37http://www.rhydolabz.com/index.php?main_page=product_info&products_id=1080http://www.comm2excel.com/projects/SIM900D_GSM_Module_Board.php?id=16#Edit:The PCBs all look slightly different. But all using the SIM900A GSM module. So the informations should work for you. By the way: There are quite a few Youtube videos with this module. It's often good to search in the comment section for links and documentation.Best regards!

author: suicidaleggroll
author_rank: Super Contributor
timestamp: April 15, 2015, 09:30:01 pm
content: The picture has an electrodragon watermark. From their site:http://www.electrodragon.com/product/sim900a-mini-dev-board/http://www.electrodragon.com/w/images/a/ac/SIM900A_schematic.pngAnd for the module itself:http://wm.sim.com/(register for an account, and then search for sim900a for command sets and such)What else do you need?

author: 0x007
author_rank: Contributor
timestamp: April 16, 2015, 06:04:13 am
content: Thank you for your replays, though this isn't exactly what I meant.I know the process of learning how to use a new piece of hardware (study schematics , code samples , protocols...).what I am looking for is some one who used this component, and can answer couple of basic questions .the module I am talking about is limited have only rs232 pins(RX,TX) an power supply so I don't really looking forward to read all the data sheets.

author: picandmix
author_rank: Frequent Contributor
timestamp: April 16, 2015, 08:41:13 am
content: Think you will have to brush up on your googling - lots of info out there.First and most importantly is where are you located ? - the 900A module, as opposed to the older 900 module, is restricted for use in areas of Asia only.http://zapro.dk/div/pdf/20111031145224.pdfIt is said to be possible to reflash it with the the firmware from the 900 module to make it useable worldwide, though for the price , as you are still learning, probably easier to buy a 900 module if you are outside Asia.The modules do have TTL ports / micro port compatible as well as rs232 as the pictures in the previous link shows.For testing out the boards you can either connect to a micro or a PC using hyperterminal or similarAgain plenty of tutorials around on ytube etc.https://elementztechblog.wordpress.com/2014/06/16/interfacing-sim900a-to-computer/This tutorial is for a 900 module from an Arduino but think it will probably work ok with a 900Ahttp://tronixstuff.com/2014/01/08/tutorial-arduino-and-sim900-gsm-modules/EditMore info and a board schematic here -http://www.aliexpress.com/item-img/Gsm-gprs-module-sim900a/1698757931.htmlhttp://www.aliexpress.com/item/free-shipping-SIM900A-module-SMS-MMS-GSM-GPRS-development-board-of-the-wireless-data-transmission-over/1981467700.htmlhttp://www.aliexpress.com/item/Free-shipping-SIM900A-mini-development-board-GSM-GPRS-core-small-plate-wireless-data-transmission-module/1517658207.html

author: janoc
author_rank: Super Contributor
timestamp: April 16, 2015, 12:30:57 pm
content: Quote from: 0x007 on April 15, 2015, 08:19:38 pmUm silly question - why to choose a module for which you are unable to find any documentation? (despite there being some, as posted by others). There are other GSM modules on the market.A good idea is to check before buying/ordering a part whether you can get documentation and the toolchain (if required), not after.

author: bookaboo
author_rank: Frequent Contributor
timestamp: April 16, 2015, 02:42:03 pm
content: Watch out there's a huge potential trap with the SIM900A... it's blocked in some regions:http://www.blog.zapro.dk/?p=368A useful AT command reference that can work through a PC terminal:http://m2msupport.net/m2msupport/software-and-at-commands-for-m2m-modules/Edit - im a slow pony, region problem has already been stated.

author: 0x007
author_rank: Contributor
timestamp: April 17, 2015, 12:08:34 pm
content: As I mentioned above it is not my part, I didn't order it ,I am simply trying to help a friend who cant speak English.things I didn't mention we are all working on a shoe string budget , the computers we use are crap and the dev boards we are using are 1000 years obsolete.that's why I asked about the specific "Sim900amini",so if some one have the understanding how to operate it so I could ask him questions.the aliexpress page is useful though didn't come up when I searched for it ,thank you.

author: picandmix
author_rank: Frequent Contributor
timestamp: April 17, 2015, 03:01:55 pm
content: This link shows how to test out a 900A module, however like many sites they do not always work as described.http://www.instructables.com/id/Using-a-SIM900A-GSMGPRS-module-in-Australia/I took my 900A module, which looks virtually the same as yours and theirs, and tried it as that Indestructables link suggests. However you will see from my picture that the 0v wire is on a different pin, so do check with a meter which of those bottom two pins is actually 0v on your module.I connected to my PC with a TTL to USB adaptor board, though you could connect to the other pins as they show via a serial connectorI also loaded the free puTTY program and ran the basic AT commands to check the communication was ok, No SIM card needed at this stage.

author: 0x007
author_rank: Contributor
timestamp: April 19, 2015, 04:10:06 pm
content: Well that is some useful data, I'll make sure it will be put to good use !and thank you on the behalf of my friend

author: suicidaleggroll
author_rank: Super Contributor
timestamp: April 19, 2015, 04:28:39 pm
content: You would get MUCH more useful information if you would just read what has been presented, apply it to your [friend's] board, and then askspecificquestions when/if you run into any problems.You've already been given links to the schematics for your exact board and the data sheet for the SIM900A module being used on it. I'm struggling to understand what else it is you think you need?