Question about Arduino Wireless SD Shield (XBEE) and serial port

Projects Networking, Protocols, and Devices
1

Hello All,

I've recently bought an Arduino Wirless SD Shield and it appears that the Hardware serial port (pins 0 & 1) will be connected to the Wireless XBee device.

I also want to be able to connect to the board via the default serial port which as I understand it also uses the same pins.

Questions.

  1. Do you know if by using the default Serial() port this will conflict with the Wireless interface?

  2. If so, is there a way I can get around this. Ideally, I would like to use the same USB cable for board I/O and debug, but would like to use the XBEE to talk to the outside world.

If anyone has any suggestions or solutions, it would be great to hear from you.

Has anyone encountered this problem in the past?

Thanks in advance,

Richard

2

you can use the softwareserial lib to communicate with the xbee, but then you'll probably need to adjust your shield

you can find that lib here

3

Thanks for the reply,

The problem I think is that both the hardware serial I/F and the XBEE serial both use the same pins....Not really wishing to modify the board is there a way around it?

I have used the Software serial library for this and currently have the XBEE reporting in on pins 10 and 11, but for this I use a prototype board and not the shield itself.

Thanks anyway, and more advice?

R.

4

Take an Arduino Leonardo. It has a USB interface built into the processor and is therefore able to communicate with the PC without using the hardware UART on pin 0 and 1. Take care if you wanna attach other shields as some of the other pins are different to the UNO too.

5

The OP says clearly that he needs to use USB only for debug purposes. Does this mean for just uploading new sketches or does this mean for realtime data gathering while the sketch is doing its thing? The Wireless SD Shield has a switch for the former purpose. With the switch in one position the 0 and 1 pins talk to the USB and in the other position it talks to the SD Card...and, I would hope, the Xbee wireless sub-shield. Is this correct?

6

Is this correct?

Almost. The SD card is not accessed by the USART but by the SPI interface and therefore is not affected by the switch position.

And because the OP says he's needing the USB for debugging (debugging is not uploading sketches but seeing the output of your debugging statements), he needs a second serial interface. The Leonardo is the cheapest way to get one.