KSU Sustainability DAQ

Data Aquisition System for Roof

2012

The DAQ system was probably the most difficult, as well as most interdisciplinary, project I have done.

Earlier, a group of students had built a system. However, it had stopped working. In the summer of 2012, I built a new system. The system monitors voltage and current off of the wind turbine, as well as wind speed, wind direction, and insolation. The data is then made available live on the website.

The controller connected to the anemometer is an Arduino(TM) Uno using the ATMega 328 chip. It is supplemented by an Ethernet board (Using the Wiznet W5100 controller) designed for the Arduino that serves the data to the sustain.ece server. The microcontroller samples wind speed and direction every second, and then every 30 seconds averages the collected data, sending that data to the server. The server is not in control of when it gets data, since data is "pushed" from the microcontroller.

The anemometer outputs pulses indicating its speed and an analog voltage indicating its direction. The microcontroller samples this data, performs some basic calculations, and sends the resulting values to the computer.

Voltage is also read across the turbine's output. Before being read by the microcontroller, the voltage level is dropped with a voltage divider, and grounds are isolated by use of an op amp. Current off of the turbine is measured by measuring the changes in voltage across a series shunt resistor.

The server is virtualized, running Linux CentOS. It also serves this webpage. When the server recieves data from the microcontroller, it enters this data into a MySQL database using a PHP script. When a user visits the DAQ webpage, the server pulls that data from the database, and displays it to the user.