Measureing and Recording of Analog Signal

1. Purpose
   
   In this section, analog signals are measured with an A/D converter and stored as ASCII text file.
   The source files measure* are almost the same to period*.
   The difference is to use A/D converter in the real time task, instead of D/A converter.
   
   
2. Materials
   
   • Program source
     • loadable module: measure_module.c
     • user space program which starts and stop the module: measure_app.c
     • header file: measure.h
   • Program source of device driver for D/A converter (A/D converter is also included)
     • header file: adc.h (the same as the previous page)
     • driver body: adc.c (the same as the previous page)
   • Makefile (the same as the previous page)
   
   
3. Installation of the module
   
   Install the module `measure_module.o' by the same procedure explained in the previous pages.
   
   
4. Execute the user space program

   % ./measure_app > foo.dat
   Starting real time task ... done.
   Waiting for record ... done.
   	

   The total execution time is 10 [sec] in this case, which is from sampling period by the number of recording samples, while these values are specified in the file `measure.h'.
   
   
5. Unload the module `measure_module' by the same procedure explained in the previous pages
   
   
6. Plot the data file `foo.dat' by using Matlab as explained in the previous page.