RS232 Question

Projects Networking, Protocols, and Devices
1

Hello,

I am new to Arduino and before ordering what I need I would like to ask some questions.

  • Is it possible to stack several RS232 shields on the same card?
  • Do I have to get the Arduino Mega if I want to stack like 3 shields?
  • Will I be able to use the USB connection to talk to a Java or C# software on my computer (with three RS232 devices connected)?

Thank you very much for your time,

Taz.

2
  • Is it possible to stack several RS232 shields on the same card?

RS232 describes a voltage level and on/off pattern for communications. Which shields are you considering, to communicate with what?

  • Do I have to get the Arduino Ultra if I want to stack like 3 shields?

You'll need the Colossal. The Ultra can only handle two shields. What the heck is an Ultra?

  • Will I be able to use the USB connection to talk to a Java or C# software on my computer (with three RS232 devices connected)?

You will be able to use the USB connection of the Arduino to talk to the PC. (Rather the Arduino will be able to.) I have no idea what the shields will be doing.

3

Do I have to get the Arduino Ultra if I want to stack like 3 shields?

I just looked at the arduino products page and didn't see anything called "Ultra".

A Google search yielded this.

I found this "compatible"

4

Thanks both of you for your answers.

Sorry for the Arduino Ultra I wanted to say Arduino Mega. Will it work with that ?

For the USB and shield interrogation here is what I want to do : Connect 3 devices to the arduino using RS232 shields and command them from the computer using USB connection.

The shield that I want to use is this one : RS232 Shield V2 - DEV-13029 - SparkFun Electronics

Do you think this setup is OK?

Thanks for your answers !

Taz.

5

To my knowledge the Mega was specifically designed to with all the header pins such that it is compatible with any and all UNO shields so you can buy any UNO shield and not worry about whether or not it is compatible with the Mega.

6

From Sparkfun's site:

This rev of the RS232 Shield provides you with the option to choose between two pins from an Arduino (D0 to D7) as software serial ports to communicate with RS232 Shield.

The comment about being able to do software serial on pins 0 and 1 is nonsense. The other pins, 2 through 7 can be used. So, you could stack three shields, and use pins 2 and 3, 4 and 5, and 6 and 7.

But NOT on a Mega. SoftwareSerial requires pin change interrupts, and pin change interrupts are not supported by all pins on the Mega. Specifically, those pins are not usable with software serial on the Mega.

7

PaulS:
But NOT on a Mega. SoftwareSerial requires pin change interrupts, and pin change interrupts are not supported by all pins on the Mega. Specifically, those pins are not usable with software serial on the Mega.

Thanks PaulS!

What Arduino do you recommend me to buy?