GSM Shield - Soft Serial

Hello everyone

I am starting my studies on arduino and have a doubt.

I’m using an arduino UNO and trying to send an SMS using a GSM/GPRS SIM900 shiled.

I keep reading texts about how to set the jumpers on the GSM board but I still don not understand how it should be done.
I send attached the part in the datasheet about the jumpers.

If I set the jumpers to use arduino’s digital ports 0 (RX) and 1 (TX), will I still be able to communicate the arduino to the ocmputer via the serial monitor?

And, I have a buzzer a relay shield connected to ports 0 and 1 in my arduino. if i set the GSM shield to use these ports as communication, will the buzzer and relay shield still work, or do I need to assign new ports to these devices?

I apologize if these questions are easy ones but I am still trying to figure out all this arduino thing.

Thank you in advance

setting jumpers.png

If I set the jumpers to use arduino's digital ports 0 (RX) and 1 (TX), will I still be able to communicate the arduino to the ocmputer via the serial monitor?

Yes, but everything you send to the Arduino will go to the GSM shield too. Probably not a good idea.

And, I have a buzzer a relay shield connected to ports 0 and 1 in my arduino.

Why? Why would anyone disable the hardware serial port just to use a relay?

if i set the GSM shield to use these ports as communication, will the buzzer and relay shield still work

Sure. All the time, whether you want them to or not. Again, not a good idea.

or do I need to assign new ports to these devices?

That would sure be a good idea.

arthuki:
And, I have a buzzer a relay shield connected to ports 0 and 1 in my arduino.

This is so utterly stupid it probably isn't true. You should check that pins really are connected, i.e. used by the shield, or are simply passing through, and thus able to be used in a sane manner.

I have just started arduino, so I believe I am allowed to make some mistakes

I have other devices attached to my arduino UNO, and due to the lack of more pins, I am using pins 0 and 1 for the buzzer and relay shield. If I use an external power supply to power my arduino I think port 0 and 1 will be free to be used for the buzzer and relay shield.

Am I wrong?

Almost certainly. I can't see any connection between whatever power you are using and pins 0,1.

Your first post implied that your buzzer shield uses pins 0,1. I bet it doesn't

Your second implied that you have the option to use pins 0,1. I bet you don't and even if you do it is s bad idea, or at least bad practice.

It may be that you really have run out of pins and are thus obliged to use 0,1 but, in that event, I would be surprised if you can do that using a shield. I rather suspect you have not run out of pins, it just looks that way.

You need to post the specs for the shield. Also a bit of detail about what you are doing. Pins 0,1 are for serial communication, as you already know, and best reserved for that purpose. Shield makers really should know this and those that don't probably have a short business career.

While most shields have a full complement of pins, not all need to be used, indeed they mostly are not and are simply there to be available for a shield above. If you look closely, you can probably see those that have connecting tracks and those that don't.

Thank you for the help. I have found some really good material about serial pins and now I understand what you guys were telling me.

Thank You very much