Does multiple arduinos communicating to a hub

Forum 2005-2010 (read only) General Frequently-Asked Questions
1

Does multiple arduinos communicating to a hub at the highes speed setting the wiring software can receive allow processing to retreve data from multipe usb arduinos going as fast as they can?
Does this work if multipe hubs are also connected?

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:o

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sorry I know it is a weird question & have not read about arduino sensor networks yet. I have 3 I am willing to try.

4
  1. The arduino is not a "High Speed" USB (2.0) device, so it doesn't need a high speed USB hub. It tops out at about 1Mbps (and that takes some special effort. 57600bps is a more usual top speed.)
  2. Multiple ardunios connected to a computer through a USB hub should work fine. I'm not enough of an expert to say when mulyiple 1Mbps USB data sources starts to be a problem for the average USB-cabaple computer, but it certainly ought to be more than one.

Does that answer the question?

5

When you say it takes some specal effort. If the arduino takes data in the spi port and is set to the top print speed that the arduino ide offers to show on the screen .

Does that mean loosing information is common at that speed if the wires are reasonably short?

It would be a new from newegg motherboard running ubuntu with at least a gig of ram.

Ok I have 3 arduino's I would like to try it. Processing will make comma seperated value text files of numbers made by the arduino's any sugjestion how to test to see if their was lost data without looking through it?

Thanks for answering.

6

You could just have each arduino send bytes sequentially from 0 to 255 and then starting over. If there are transmission errors the bytes wil be out of sequence on the recieving end.

7

wires are reasonably short?

That is not important. You only loose data if the program at either end can't keep up with the speed it arrives.
So take for example Hyperterminal on the PC, this will loose data at even 2800 baud sustained output because it is rubbish.
Receiving data and displaying it are two different things. In general you can receive data much faster than it can be displayed on a screen.
All the Arduino / PC USB link consists of is a serial link with the host (PC) providing serial to USB conversion and the bridge chip on the Arduino providing USB to serial translation.

Hope that is clearer.