GSM SIM900 module replacement problems - Migrating to A6

Hello … First Nice Work
i Have GSM sim900 replaced … but some of something’s not work i think
First i used AT commend that u tell in video to put it sleep but nothing happend still he got about 30ma .
second i used your Code for receive sms and not working …
and how i can start gps ?!
the problem is in chip or what !!
can u show us code function like …
if i have sensor to get value so if sensor get like over number 50 send sms … so i did this code … i need how i can set thia value by sms … thnx
this is my gsm :

https://m.ebay.com/itm/GPRS-Pro-Serial-A6-GPRS-GSM-Module-Core-DIY-Developemnt-Board-Replace-SIM900-K9/222316665007?_trkparms=aid=222007&algo=SIC.MBE&ao=1&asc=41375&meid=f0eb477ce2b54be28e987e11defb1d3f&pid=100623&rk=2&rkt=6&sd=162322523513&_trksid=p2047675.c100623.m-1&_mwBanner=1

Hi,
Thank you for the appreciation.
I see that you are using A6 module now, which might not always have same compatible AT commands as SIM900. But standard AT commands for call and SMS should remain same. Please double check in manual.
The GPS is not available in A6 or SIM900. They don’t have the functionality.
But SIM900 can give network Location.
The code I showed is for demo only. You need to take care of responses from module and provide appropriate delay after boot up.
I will definitely give you some hints on how to write code for that to send SMS when a value is exceeded.

Thanks your Replay
If My models A6 not support all AT commend
Can u tell Me which Model is good for All AT commend and support GPS
i meen GPS in My model i need just to send sms with his location that is all i need …
finally I meen with sms … i will explain more
i set value for sensor when he get it it send sms Ok …
but i need code that if i wana change this value in anytime by sms if the product is far away of me so i need to send sms to change this value how i can do it ?!!!

Keeping Up … Nice Work !!

If you need to use GPS functionality then you need to use a separate standalone GPS module along with SIM900, or you need to use modules which have GPS built in, like SIM808 or A7.

If you need to change the values by SMS you need to follow the video on which you commented.


Just collect the data incoming on port and match the command. I showed this in the video. Then store the parsed value into buffer.

How to store it in buffer … note i used this code be4 and nothing happend :frowning:

I am storing it in buffer in code. Did you use this code with SIM900 or A6 module ?
There can be multiple problems. Were you waiting for enough time after power up before sending initialisation commands?
Show me your full code so that i can suggest what could be wrong.
To debug better you need to watch whats going on using a terminal software as Arduino terminal will only show you what Arduino is sending and not what module is responding.
Before trying out any code, try the AT commands manually using a terminal software. Once you get it working then only go for Arduino.

I tryed only your code i didn’t add anything else and it’s not working … so i will try use gsm only send at commend to it and i will see if it work i will go to Arduino like u told me
i used code on A6 Model that i sens pic for it

sms will store on this buffer for ever until i change it again with sms ?!

I have written that code for SIM900 only. Havent tried on A6.

The code i showed collects the contents of incoming UART data and matches a command in it. So whenever a message comes in, it is read into that buffer and stored there until next AT command response or SMS arrives.
Its just collecting data from module, It can be any command response like OK or it can be SMS data also.

Thnx … I will try to change model which one u prefer ?!
Question !
i maked program VB to control Led and its work fine thnx god … and vb read data from arduino and show in program vb …
only i need to use if condition in vb when i get read data from arduino if = A do something but not working i declare Variable and maked it = read from arduino and maked if condition but not working i dont know why can u tell me how i resolve this problem thnx

In the VB also you have to collect incoming data and search for a particular string using string search functions to find out if a particular string is present and take action.
You can use SerialPort components interrupt option in VB to do that. I have not tried VB but C# i had used some time back. They are almost same.

I recommend SIM808 modue for GPS and GSM

Can i Upload Code Of both Arduino And VB to see the problem …
i did i use string variable and code is right but if condition read but not do action idk why

As i said,

  • First capture AT command transaction data that is being happening between module and PC. This will show something is coming but we are not able to capture it.
  • Then in VB code you have to put break points and see when data arrives to serial port, you can easily see data in watch window.