I think that analog DAQ with 30 channels would be an overkill for such an application.
If you need to give each competitor 4 options, why not choose between one of the following options: 1. 120 digital channels (5 digital DAQ modules at 24 channels each) and provide each competitor with 4 channels, each one connected to its own pushbutton. 2. If you prefer to build 30 4->2 encoders, each getting inputs from 4 pushbuttons and providing 2 digital outputs, then you'll need only 60 digital channels (3 digital DAQ modules, with 12 digital channels to spare). Of course, the final choice involves price tradeoff between: - Analog DAQ with 30 channels + 4-pushbutton with resistors module - Digital DAQ with 120 channels + simple 4-pushbutton module - Digital DAQ with 60 channels + 4-pushbutton with encoder module I assume that data processing speed is not a limiting factor. --- Omer On Wed, 2011-04-06 at 15:54 +0300, yosi yarchi wrote: > Hi > > This is interesting idea. However, it support voting between 2 > options, only, while I need at least 4 options. > I thought that combination of analog DAQ and 4 push buttons with > analog output may help here. > Does someone have an idea about such combination (analog DAQ+edge > unit)? > > With best regards > Yosi Yarchi > > > > > > On 04/06/2011 10:55 AM, Jason Friedman wrote: > > I think the best solution would be to use a data acquisition device, > > either USB or PCI. > > > > > > Measurement computing sell relatively cheap devices, e.g. this USB > > one for $99: > > http://www.mccdaq.com/usb-data-acquisition/USB-1024-Series.aspx > > > > > > can measure 24 digital channels (you could get two if you need 30). > > > > > > Each "competitor" could have a small switch, which connects their > > input line to say a 5V power supply. > > > > > > You can then write a very simple program to detect when each > > competitor presses their switch > > (with sub-millisecond accuracy!). > > > > > > These devices apparently have linux support. > > > > > > Jason > > > > On Wed, Apr 6, 2011 at 2:44 PM, yosi yarchi <yosi.yar...@gmail.com> > > wrote: > > Hi all > > > > > > I need application that will be able to collect and process > > inputs from 30 (!) competitors, and will display the results > > very fast. The ideal solution could be to collect the inputs > > via SMS: each competitor send his answer, the application > > collect the answers (related to phone number) and process > > them. However, I can't assume that the competitors have > > mobile phones (they may be little childs...). > > > > > > I thought to use 30 USB numerical keyboards as input > > devices, connected with cables to 3 hubs, connected to the > > computer. > > > > However, I don't have experience with USB drivers at > > linux... > > > > > > Is it feasible? What should be the main guidelines for the > > solution? -- In civilized societies, captions are as important in movies as soundtracks, professional photography and expert editing. My own blog is at http://www.zak.co.il/tddpirate/ My opinions, as expressed in this E-mail message, are mine alone. They do not represent the official policy of any organization with which I may be affiliated in any way. WARNING TO SPAMMERS: at http://www.zak.co.il/spamwarning.html _______________________________________________ Linux-il mailing list Linux-il@cs.huji.ac.il http://mailman.cs.huji.ac.il/mailman/listinfo/linux-il
