SMS Text using a GSM Modem and a Microcontroller PIC16F877A.

nbrady

Hi Folks,

Hope someone can provide some advice on where to start with this project I am working on. I need to use the PIC16F877A microcontroller to detect certain conditions (this part is easy) and when the corretc conditions are met i need to send some basic information via a SMS text message to the owner or a few numbers. I want to use the simplest method possible to just send basic text data. I have looked at alot of GSM modems on the web and they all appear to come in large (approx 4"x4") units and are cost approx €150 e.g (http://www.roundsolutions.com/shop/en/GSM-Modem/Module/GSM-GPS-module).

Any simple microcontroller to mobile phone communication method you can suggest would be appreciated and low cost too if possible. tnx..

syncosised

Those modules you linked to all have GPS as well as GSM. You don't mention the need for GPS in your description, so you should look for ones without it. That should reduce the cost significantly. Unfortunately, I can't help you much with suggesting a device as I've not got a lot of experience in that area.

nbrady

thank you, that is a good catch. I do not need a GPS function. Lets hope someone else can help. tnx.

kenon

You will need to acquaint yourself with AT codes.

Heres a nice small cheap GSM modem as well.

This thread should probably be in the engineering forum as well.

nbrady

Thank you Kenon, can you clarify a few things for me please if possible.

1. Do all GSM modems use a SIM card? And does the SIM come with the modem? Is the SIM contracted to a particular service provider?

2. Is there a ongoing charge for using a GSM modem in this way with a SIM? i.e. is there a cost per data transfer like a text message?

tnx.

kenon

nbrady wrote: »

Thank you Kenon, can you clarify a few things for me please if possible.

1. Do all GSM modems use a SIM card? And does the SIM come with the modem? Is the SIM contracted to a particular service provider?

2. Is there a ongoing charge for using a GSM modem in this way with a SIM? i.e. is there a cost per data transfer like a text message?

tnx.

1. Most GSM modems I have come across use a SIM card that is not provided with the modem. The SIM card is a normal SIM card, like the one in your phone. So it would be tied to the network that issued the sim card and you would be using that network for texts, GPRS etc.

2. It would be working exactly like a phone so yes you would be charged. I would advise you to use text bundles or use a network's free text offer.

Hope this helps.

nbrady

Thank you, yes that is clear.
Now I hope someone can help further with my original request below on the PIC and GSM Modem interface, what code to use etc..

Hi Folks,

Hope someone can provide some advice on where to start with this project I am working on. I need to use the PIC16F877A microcontroller to detect certain conditions (this part is easy) and when the corretc conditions are met i need to send some basic information via a SMS text message to the owner or a few numbers. I want to use the simplest method possible to just send basic text data. I have looked at alot of GSM modems on the web and they all appear to come in large (approx 4"x4") units and are cost approx €150 e.g (http://www.roundsolutions.com/shop/e...GSM-GPS-module).

Any simple microcontroller to mobile phone communication method you can suggest would be appreciated and low cost too if possible. tnx..