Some basic questions from an Arduino beginner

Hello, I'm a new member here in the forum. It's been about half a year since I started to deal with Arduino. First I bought a very nice book and I learnt a lot of things (I knew already programming in C++,C and basic electronics) about Arduino. Now I want to make a project but I have some very basic questions - some of you may find them silly I know - about some importanth topics on my project.

  1. Can I use the GSM module like this? --> when I send different SMS messages the Arduino will do different things. For example if I sent an SMS "A", Arduino will open a pump, if send "B" Arduino will control a DC motor, if I sent "C" will open a door etc. Is that possible through the GSM system?

  2. How many step motors, DC motors, Servo motors can an Arduino UNO or an Arduino Mega manage at the same time?

  3. How many things can an Arduino Mega manage at the same time - generaly speaking? For example can an Arduino Mega control in the same time 2-3 sensors, be on vigilance for an SMS from GSM module to do interupts (motor controling, pump controling and other), write on an SD Card the history of some sensor measurements and other possible things?

Thanks a lot for your patience reading my first message here. I'm looking forward to see your answers. Good afternoon.

  1. Yes.
  2. Several. How many do you need to control?
  3. Yes, for the example. There are a number of working examples on the web.

You may be interested in the demo Several Things at a Time

...R

Thans a lot for your comments. I have some more questions.

  1. So, the SMS messages that Arduino will recieve can manage them as string variables?

  2. Can I control the motors with simple ICs or I need some motor drive boards that I saw on the internet?

  3. In some exambles I see that the GSM module hardware is placed exactly over the Arduino board and in some other exambles (fewer) I see that only a few pins are needed for the GSM-Arduino connection. Which is the best way to install the GSM and not to take a lot of pins from my Arduino?

  4. my biggest concern is that if I make a project with GSM, SD card reader, a few motors, some sensors, an LCD display etc, Arduino will not have so much pins (ins and outs) for that perpose.

Which is why they made the Mega.

Or an Uno screw shield so the signals of the shield-covered pins are still accessible.
http://www.crossroadsfencing.com/BobuinoRev17/
Uno & Mega versions


mplaksant:
7) my biggest concern is that if I make a project with GSM, SD card reader, a few motors, some sensors, an LCD display etc, Arduino will not have so much pins (ins and outs) for that perpose.

This is going to remain uncertain until you gain more experience. You need to be able to define the requirements (exact sensors, exact number and type of motor driver etc) before you can calculate how many pins and what kinds of pins (PWM, analog, external interrupts etc) are required.

A Mega probably gives you the best chance of fitting stuff in. But it is not necessarily compatible with shields that work on an Uno.

Whatever you decide it will be sensible to start learning about each of the parts (GSM, DC motor, servo, sensor) separately. That should give you a chance to build your knowledge before committing to all the hardware decisions. Don't think about joining everything together until you have everything working separately.

...R
Planning and Implementing a Program