i need obtain ADC data from mini2440 and display the plot on the browser via LAN, any suggestion? I already installed web server inside mini2440 and there is no problem for me to access the data from remote host, only the problem is how to obtain ADC data and show it in plot form on the browser?
To get the ADC data I'd suggest reading the chapter in the QuickStart guide here: http://www.oselas.org/oselas/bsp/pengutronix/mini2440_bsp_en.html To plot the data I use rrdtool. Fortunately, there are many good examples of to use it because it is quite a "complex" programming language. It can generate .png files. Can your web server handle those? There are several other plotting programs: PHPplot, gnuplot, ...
thx davef. I'm using thttpd webserver with php5 and cgi installed in mini2440. I can get ADC data by following this link-> http://farm2440.blogspot.com/2011/06/creating-web-interface.html. I think only the ploting software is what i need now to let other user remote view the graph of adc data. I think i will try using rrdtool or PHPlot to plot the graph. But i wonder which one is more easy to learn. Sorry for my bad english and i'm newbie here.
Did you enable thttpd to use PHP5? I used a script developed at my previous job, as it was beyond my skills to get it to work. What version of thttpd do you use? I had to stick with 2.21, which was OK. I can't remember why I didn't persist with PHPplot. PHP5 (I think ) was enabled to run PHPplot (gd), but there must have been some problem as actually writing the scripts to do the plotting is quite easy. ImageMagick was helpful with PHPplot. rrdtool is well supported, but you do need to carefully read through the material. You can do some quite complex stuff with it. There are good examples of setting up a rrdtool (flat) database, update scripts and then the actual graph writing scripts. A problem with rrdtool is getting it cross-compiled for the mini2440. Fortunately, the Pengutronix BSP has a box that you can tick for rrdtool and what is better it actually worked out of the box. I never used cgi so don't know what is involved in getting suitable plots with that functionality in PHP. Dave
i'm using thttpd-2.25b with php5 by following the link->http://singleboy.blog.163.com/blog/static/54900194201153082030849/ and it works. thanks for your suggestion, davef. I will give it a try.
Interesting, although I don't understand non-English part of it :( I will try Google translate and see if that helps. I think the issue with PHPplot was that it needed to be cross-compiled as well ... and often that process didn't work out well for me! The man who has written excellent tutorial material for rrdtool is Alex van den Bogaerdt. Good luck!
if you facing any problem, you can ask me here. And i'm using fedora 9 i386 OS in my vertualBox, not CentOS 5.5. Good luck!