HI William, There are a few different methods you can use to accomplish this. Just keep in mind that I have been doing a lot of reading lately on Node.js( the last year or so ), but I am no expert.
First if the input you're reading is accessible via sysfs, you can use process.exec( I think it is ) to read the value into a javascript variable to display on the webpage. Secondly, I believe you could write an app that reads the value( perhaps using mmap ), and puts it into a "file" in memory, then use process.exec( again ) to cat the value into a javascript variable much like the above approach. Anyway, there are surely other options and the two I mentioned above may / may not be the best approach. This is just something that I've been researching myself for the last year or so in my spare time "wondering" How I personally could achieve a similar goal. http://stackoverflow.com/questions/12941083/get-the-output-of-a-shell-command-in-node-js The above is one such link I believe that I came across at one point I though seemed useful. BTW, you probably ran into the same alarm clock "app" I ran into recently that I thought was kind of cool :) On Sun, Jun 8, 2014 at 5:03 PM, William Pretty Security < [email protected]> wrote: > Thanks for the reply John > > > > I found a really good tutorial on the web that uses socket.io to display > a clock on a web page. > > So modifying the code for my purposes was a snap J > > > > I’ll look into DoJoToolkit anyway. > > > > Bill > > > > > http://www.packtpub.com/building-a-home-security-system-with-beaglebone/book > > > > *From:* [email protected] [mailto:[email protected]] > *On Behalf Of *John Syn > *Sent:* Sunday, June 08, 2014 7:13 PM > *To:* [email protected] > *Subject:* Re: [beagleboard] Re: Reading an Analog input from a web page ? > > > > > > *From: *William Pretty Security <[email protected]> > *Reply-To: *<[email protected]> > *Date: *Friday, June 6, 2014 at 6:01 PM > *To: *<[email protected]> > *Subject: *RE: [beagleboard] Re: Reading an Analog input from a web page ? > > > > Hi Mark; > > > > Thanks for the response. I looked at the links, and I think it would be > easier if provided more detail. > > What I am trying to do is a lot less complex (I think) than your examples. > > > > As part of my latest book for Packt Publishing, I have an RF Power Meter > design. > > Basically you read an analog voltage which is proportional to the RF power > being measured. > > (It could just as easily be temperature) multiply by a correction factor > to convert millivolts to dBm and then > > print out the result. > > > > I already have test software that does this to the console, but I want to > now output it to a web page. > > The web page already controls a programmable attenuator, using socket.io > and toggling IO bits. > > I don’t need to graph anything; just print a number on the web page that > corresponds to the RF power. > > > > I found a couple of files in your git tree called “ioPlot.html” and > “ioPlot.js” > > but I am not sure how to simplify them for my application. > > Why not use DojoToolkit and Node.js? I suggest you use websockets which is > easy to implement in a Node.js web server and also in javascript on a web > client. > > > > Regards, > > John > > > > Thanks; > > > > Bill > > > > > http://www.packtpub.com/building-a-home-security-system-with-beaglebone/book > > > > *From:* [email protected] [mailto:[email protected] > <[email protected]>] *On Behalf Of *Mark A. Yoder > *Sent:* Friday, June 06, 2014 4:51 PM > *To:* [email protected] > *Subject:* [beagleboard] Re: Reading an Analog input from a web page ? > > > > p.s. I also have a homework[1] assignment that gives an overview of it. > > > > --Mark > > > > [1] https://drive.google.com/#folders/0B5UNMAgIJB74cUhIRlRwcXdQaTQ > > On Friday, June 6, 2014 3:44:36 PM UTC-5, Mark A. Yoder wrote: > > William: > > I have an example[1] that not only reads analog in, but it also plots it > on a web page. > > > > --Mark > > > > [1] > https://github.com/MarkAYoder/BeagleBoard-exercises/tree/master/realtime > > On Thursday, June 5, 2014 11:09:58 AM UTC-5, William Pretty Security wrote: > > Hello group; > > > > I am wondering if is possible to read an analog input on the BBB at the > press of a button on a web page. > > I already have code that uses node.js and socket.io to turn on an LED in > response to a button push. > > But I want to Read an input and display the result. > > > > Does anyone know how to do this ?? > > > > Thanks J > > > > > http://www.packtpub.com/building-a-home-security-system-with-beaglebone/book > > > > -- > For more options, visit http://beagleboard.org/discuss > --- > You received this message because you are subscribed to the Google Groups > "BeagleBoard" group. > To unsubscribe from this group and stop receiving emails from it, send an > email to [email protected]. > For more options, visit https://groups.google.com/d/optout. > > > No virus found in this message. > Checked by AVG - www.avg.com > Version: 2014.0.4592 / Virus Database: 3955/7631 - Release Date: 06/06/14 > ------------------------------ > > No virus found in this message. > Checked by AVG - www.avg.com > Version: 2014.0.4592 / Virus Database: 3950/7548 - Release Date: 05/23/14 > Internal Virus Database is out of date. > > -- > For more options, visit http://beagleboard.org/discuss > --- > You received this message because you are subscribed to the Google Groups > "BeagleBoard" group. > To unsubscribe from this group and stop receiving emails from it, send an > email to [email protected]. > For more options, visit https://groups.google.com/d/optout. > > ------------------------------ > > No virus found in this message. > Checked by AVG - www.avg.com > Version: 2014.0.4592 / Virus Database: 3950/7548 - Release Date: 05/23/14 > Internal Virus Database is out of date. > > No virus found in this message. > Checked by AVG - www.avg.com > Version: 2014.0.4592 / Virus Database: 3955/7644 - Release Date: 06/08/14 > > -- > For more options, visit http://beagleboard.org/discuss > --- > You received this message because you are subscribed to the Google Groups > "BeagleBoard" group. > To unsubscribe from this group and stop receiving emails from it, send an > email to [email protected]. > For more options, visit https://groups.google.com/d/optout. > > -- > For more options, visit http://beagleboard.org/discuss > --- > You received this message because you are subscribed to the Google Groups > "BeagleBoard" group. > To unsubscribe from this group and stop receiving emails from it, send an > email to [email protected]. > For more options, visit https://groups.google.com/d/optout. > -- For more options, visit http://beagleboard.org/discuss --- You received this message because you are subscribed to the Google Groups "BeagleBoard" group. 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