How to Send a voice message using SIM300 and 8051 Microcontroller

[MDSHUJAUDDIN]

Hi Guys good to be here ,i need ur lil help .

I am using GSM SIM300 Controller, i want to send Voice Message from this SIM300 to the Mobile Phone .Can any one help me . Which commands are used to perform this and how to add Audio message into the coding ......?


Waiting for ur replys...

 

[GSM Man]

There is no support for "Voice Messages" in the SIM300. You would need to place your message in an external "Audio Player" (i.e. https://www.radioshack.com/product/index.jsp?productId=2102855) and connect its output to the SIM300's MIC input. To play the message you would need to place a "Voice Call" and then play your message.

 

[MDSHUJAUDDIN]

Nice to see Ur reply ..!

Instead of "Audio Player" can i use "APR9600 Voice recording/playback IC" to play my message ..... I mean like we will store a predefine audio message and playing it on answering a voice call.

I have referred few circuits related to Interfacing of 8051 with APR9600 just like (https://electronicseverywhere.blogspot.in/2012/09/cellphone-based-device-control-with.html)for Cellphone-Based Device Control With Voice Acknowledgement.But i want to use it for playing just audio message

Can you plz help me out for interfacing circuit and Coding logic ......!

Waiting for ur reply ..

 

[GSM Man]

Yes, you can use the APR9600. You'll need to connect it's output to the MIC input of the SIM900 - refer to the SIM900 documents for details.

 

[MDSHUJAUDDIN]

Thanks for Ur reply

I want to conform, the way i have interfaced the SIM300,8051 & APR9600IC(In Random Access Mode) shown in the image is correct or not . If its Ok Then i want to know the coding logic further

Waiting for your reply ....

 

[GSM Man]

That interface is for a microcphone. If you want to connect a line-level signal you need to refer to this document: http://www.svtehs.com/simcom/docs/SIM900_AN_AudioIN_V101.pdf

Use the "ATD" command to make a call, and then play your message!

 

[MDSHUJAUDDIN]

Thanks for ur kind and favorable reply ...........

But in my application i am using SIM300,

1Q)So for SIM300 which interfacing will be suitable ....?

2Q)Can i use SIM900 Interfacing circuit for SIM300 ,Does it Support ?

3Q)Moreover Der are three interfacing circuits shown in SIM900 Document,
(a)Audio Input 1 Single Ended LINE-IN Configuration
(b)Audio Input Difference LINE-IN Configuration
(c)Audio Input 2 Single Ended LINE-IN Configuration,which configuration will be suitable?

 

[GSM Man]

The audio circuit of the SIM300 and SIM900 are similar so you can follow the SIM900 design recommendations. Since there are 2 speaker pins on the APR9600 I would choose the differential input circuit (figure 2).

 

[MDSHUJAUDDIN]

Have a look over this modified interfacing image .....

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Can i go with dis circuit ........?

 

[MDSHUJAUDDIN]

And i also wanna know about ISD Diodes .....?

Waiting for ur reply ...!!!

 

[GSM Man]

You have the -Speaker output connected to the +Mic input, and the +Speaker output connected to the -Mic input; you need to connect - to - , + to +; Also, note that the output of the APR9600 is 1.4 volts, while the SIM300 maximum input voltage in differential mode is 100mV. You'll need to add an attenuation circuit between the 2 devices to reduce the voltage level.

And i also wanna know about ISD Diodes .....?

What about them?

 

[MDSHUJAUDDIN]

Oops...! u mean Terminal Swamping ... ok i will make it correct ,any how thanks for pointing it out ..!

Regarding ISD Diodes ,i wanna know whether its a single device or a combination of a Zener and a Diode ..?
As i have seen it in a interfacing circuit of Microphone and SIM300 Controller , in its datasheet.Further what will be its actual application and why its used ..?

 

[GSM Man]

I'm not sure what the exact structure of the ESD diodes are. However, they act like a Zener diode with a low forward breakdown voltage and a low reverse breakdown voltage, so they conduct if the voltage goes above/below +/-5 Volts. They're intended to prevent damage from Electrostatic Discharge and are generally attached to pins that the end user may be able to touch (such as the SIM Card socket pins).

 

[MDSHUJAUDDIN]

Ok Fine ,Thanks for ur reply .......

This is the circuit ,in which i have seen the use of ISD Diodes first.Anyhow i am not using this circuit in my project but wanted to know about it ..?
.

And one more thing ,Is there any other Low cost Voice recoeding and Playback IC apart from APR9600,ISD1420,ISD100 present ....?

Waiting for your reply ..!

 

[GSM Man]

On a typically handset the the user is likely to touch the microphone and those diodes are there to protect the device from static discharge.

I don't know what voice record/playback IC's are on the market, but you may want to look at Holtek Semiconductor. I know they make a variety of specialty audio devices.

 

[MDSHUJAUDDIN]

ok Fine thanks for ur suggestion ....!

 

[MDSHUJAUDDIN]

Hey hi "GSM Man" im back......!

Is there any method to "subscribe to the SIM of GSM module" ...I mean if type a message like "SUBSCRIBE_SIM300" from my mobile phone(with a mobile number 9898989898) and send it to the GSM Module SIM number ,then from next time ,this module should be able send me the message .

What i actually wanna do is:
1.Receiving a Message1(Eg:SUBSCRIBE_SIM300)from a Number1(Eg:9898989898)
2.Storing the number(9898989898) for only this kind of messages
3.Using this number(9898989898)
4.Next time Sending a message to "9898989898" from GSM SIM300 Controller SIM

........waiting for ur usual kind response ...!

 

[manikandanshine]

Yes, you can use the APR9600. You'll need to connect it's output to the MIC input of the SIM900 - refer to the SIM900 documents for details.

is it possible to voice call by using gsm modem
if it is possible,can u explain the process is done....can u help me....

(i am using fargo maestro 20 gsm 900/gprs1800 modem).....

thanks in advance....

 

[GSM Man]

Hey hi "GSM Man" im back......!
What i actually wanna do is:
1.Receiving a Message1(Eg:SUBSCRIBE_SIM300)from a Number1(Eg:9898989898)
2.Storing the number(9898989898) for only this kind of messages
3.Using this number(9898989898)
4.Next time Sending a message to "9898989898" from GSM SIM300 Controller SIM

Sure, but you have to add the code to your micro-controller to accomplish that.

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is it possible to voice call by using gsm modem
if it is possible,can u explain the process is done....can u help me....

(i am using fargo maestro 20 gsm 900/gprs1800 modem).....

thanks in advance....

I'm not familiar with that modem and don't know if it supports voice calls. Modems that do typically provide commands that comply with the "V.25TER" specification. The V.25TER command for making a voice call is "ATDn";where n is the phone number - i.e. "ATD19085551212".

 

[manikandanshine]

Sure, but you have to add the code to your micro-controller to accomplish that.

- - - Updated - - -

I'm not familiar with that modem and don't know if it supports voice calls. Modems that do typically provide commands that comply with the "V.25TER" specification. The V.25TER command for making a voice call is "ATDn";where n is the phone number - i.e. "ATD19085551212".

do u have interfacing with gsm modem+aprp600.....if u have means,plz help me...