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Topic: Q: About Arduino + GSM Sim900d (Read 3418 times) previous topic - next topic

paldong

Hi! just wanna ask on how to mount my gsm sim900d module to my arduino. What i would like to do is ill make use of my gsm module to act as an trigger together with my arduino. The scenario is like a switch where ill text my module with a corresponding code and then my arduino reads the message and when its valid it triggers the arduino to draw an output of 5v in the pin 5 where it is connected to my other which turns off the relay..pls help me :)

Hideout

First you'll need to hook the GSM module up to your Arduino, this might not be as simple as you think...

If you're running a standard 5V Arduino you need to implement level changrs on the RxD and TxD signals
You must also build a power supply to the GSM module (~4V), an d this power supply must be so 'stiff' that it does not drop more than 3-400mV at the transmitter bursts (that's 2-3Amp).
A SIM card holder is also needed
Dont forget to connect an antenna

How do you plan to power the module on? You can implement a simple swich to do this or you can do this from the Arduino with the help of a transistor

What I'm trying to say is that it is not as easy as you might think.... You might want to google a bit around for schematics of GSM shields, then you can see what you're up against...

Once you decided on the HW you can get going on the SW, there google can be your friend again and help you to locate some sample code...




paldong

I've done connecting the gsm sim900d to my arduino and it works fine i can send & receive message. Now what I am trying to do is I will light up a led with a text message is there any code for that?

putyn

#3
Dec 07, 2011, 04:14 pm Last Edit: Dec 07, 2011, 04:17 pm by putyn Reason: 1
nop not really - you need to see how your gsm module its "reacting" to a new message (mine a tc35 will send a command over serial) , then youll write some code to check for this particular command if you get a new message process the message and see what you need to do with the led

hope this helps

enzoi

I saw some sort home automation project on net.,.,i hope to learn same idea...to have an embedded program in the arduino together with SIM900d GSM module hooked up...that would interpret the text messsage and use it as an execution command... I hope to catch the attention of our hobbist and i would really appreciate great helps.

hey12

Sir i have 9 V power supply with a current rating of 0.4 A. i tried to split the supply, one at atmega arduino with 9 V, and the other was 5 V which i regulated to supply GSM module. But it didn't work, the GSM module did not turn on. can you help me hoe can i troubleshoot this matter tnx?. smiley

putyn

how did you split the power supply ? try using lm7805 voltage regulator to get a 5v for your atmega mcu

do you have a breakout board for your sim900 or how are you going to use it in your circuit ?

wonderArmy


I've done connecting the gsm sim900d to my arduino and it works fine i can send & receive message. Now what I am trying to do is I will light up a led with a text message is there any code for that?



hi what code did u use for sending and recieving message... i am doing a project that can send and received text messages but the recieving text messages is not consistent on reading the recieve message... what might be the solution forthat

coopapi

If you find a way to light LEDs with sms messages, let me know.  :)

kitlog


I've done connecting the gsm sim900d to my arduino and it works fine i can send & receive message. Now what I am trying to do is I will light up a led with a text message is there any code for that?


hi what code did you used to send and receive message? tnx!

alnath


I've done connecting the gsm sim900d to my arduino and it works fine i can send & receive message. Now what I am trying to do is I will light up a led with a text message is there any code for that?


Given the fact that you can read the received SMS, you can do everything you want. All you have to do is to compare the SMS content with the string you decide that will light on the led : 
say if the SMS content is "ledon" (just an example ;) ), then set the output driving the led HIGH : 
Code: [Select]
digitalWrite(output_led, HIGH); , if the SMS is "ledoff" , set the output LOW: 
Code: [Select]
digitalWrite(output_led, LOW);  .
If you don't know how t compare strings in C, it is a programming question. If you  google "compare strings C" , you'll get tons of answers, one of these is here http://www.programmingsimplified.com/c-program-compare-two-strings

hth,
jf

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