Software continued

   Among the difficulties encountered, are the coordination of tasks among several different languages. The timeline begins with data being read from hardware, a file is opened and the data written to the file. The file name is taken from the current date, the reasoning is, the current date constitutes a unique identifier that insures no two files will have the same name. The script reading the data is initiated by a service script used by the computer operating system to schedule tasks. The 'service' calls the data reader script. That script runs another script that gets the calculated solar azimuth and elevation for the current time. There is an option in that script to get previous and next sunrise and sunset times used in setting the schedule. A service timer script may eventually be used instead of rise and set times. The azimuth and elevation data are written to the opened data file along with the hardware derived data. The data reader also calls another script that creates a webpage that gives a brief overview of the station's current activity. Another webpage, pre-written, opens the day's data file and draws a line graph chart based on that data. Two data reader scrips/services run simultaneously. One collects all 22 variables every 30 seconds. The other collects four variables' data. The latter is the brief form and is the one from which the line graph is drawn.
   All of this is done with several scripts and 5 languages. An additional modification will create a permanent image of the line graph chart for long term storage, a snapshot of that day's activity.
   With all of this, there still remains the programming of the linear actuator(s) that will position the array for maximum exposure to the sun. Some improvements in the area of charting and data storage may be in the future. The computer uses a 16gb SD card for main storage. A packing program could reduce the amount of storage space used by the accumulating data files, by 80%. The amount of storage space used by, even a year's, data, is so small as to make the amount almost negligible.

   Changes made in the computer include downloading and installing many programs. The computer is programmed for wi-fi, both as a client, and as a server. This makes remote collection of accumulated data easier than going to the station and physically hooking a laptop or other device, to the computer to get the files. The languages have to be installed. Programs associated with several pieces of externally added hardware have to be installed and configured.  Periodic tests have to be run during the computer setup to insure each program is installed correctly, before moving on to the next stage. One mis-configured application can cause, seemingly, mysterious problems later on.
   Once the computer is setup, a system test is needed to make sure everything is running together smoothly. Hardware tests improve reliability. Among the additional hardware are the analog-to-digital converters that convert voltage and current readings to the binary language usable by computers. The current sensing resistors, bypass diodes, sun sensor cells, fuses/breakers, all have to be tested and calibrated.