The purpose of this task was for our co-op student to create a program using the LabVIEW build it software to measure voltage of a small solar panel and then display the data in the form of a waveform chart. He was also told to create a numeric indicator that tells the specific voltage as time goes by. Here is his description of the project.
I started with simply assembling the myDAQ hardware device and connected it to the protoboard that was needed to complete the task at hand. By using the Analog Input (AI) present on the myDAQ, I connected the solar panel. The red wire, which is positive, was connected to AI 1+ and the black wire, which is negative, was connected to AI 1-. To complete the circuit, I needed to ground the 1- by simply connecting the AI 1- to Analog Output (AO) AGND. AGND is the ground terminal (FIGURE 1).
Then I connected the myDAQ to the computer. I started up LabVIEW and created a new virtual instrument (commonly referred to as a VI). In the block diagram window, I placed a data acquisition assistant, commonly known as the DAQ Assistant. As I did so, a new window opened with the following two options: “acquire signals” or “generate signals”. I chose acquire signals and then selected analog input because the solar panel is connected to the AI of the myDAQ device. This gave me a choice of items that can be measured. I selected voltage and then proceeded to select AI1 and hit Finish. (FIGURE 2).
Next, I went on the front panel and added a waveform chart and connected the data of the DAQ Assistant to it.(FIGURE 3) I also added a numeric indicator by right clicking on the wire connecting the waveform chart and selecting create numeric indicator. Next, I was told to add an LED that turns on when it is given a value lower than the value coming in from the solar panel. To do this, I had to first connect the LED to the DIO terminal 7 and then connect it to ground. I then created another DAQ Assistant, but this time I choose generate signals and selected digital output and then clicked on line output. (FIGURE 4) I then selected port0/line7 because this is where I have connected my LED and hit Finish. In the following pop-up window, I selected the necessary options that were needed to successfully complete the task and then clicked OK. Next I proceeded to add a comparison function of Less?, and connected the x input to the data of the DAQ Assistant and connected the y input to a Slide which was added on to the Front Panel.(FIGURE 5) The Slide determines the value of the LED. On the Front Panel, I added a Boolean LED which I connected to the output of the less function. So if the value of the slider was less than the value of the solar panel the LED
would turn on and if it was greater than the value of the solar panel it would turn off.
In the end, I learned how the blue DAQ assistant express virtual instrument can be used to get the data from the analog input terminals of the myDAQ. I also learned how to create a waveform chart in order to display the voltage signal in a visual form. From doing this simple program,
I have gained knowledge on how to create a variable that can control when the LED turns on and off, depending on the voltage coming from the solar panel. In conclusion, this was a great exercise that shows the true potential of solar panels and how one can utilize the energy of the sun, in the form of electricity. Find out more about National Instruments offerings for students, schools and teachers at studica.com. There are also a variety of miniSystems designed for the myDAQ and accessories. One of the most recent is the mySTEM™ Project Board.
