Problems...

Week  8

            Week 8's main objective was to finally obtain signals from both the EOG and EMG electrodes. This seemed plausible because the drivers were installed on the computer and the batteries were attached to the circuit boards, unlike the previous week.  After placing the electrodes and turning everything on, no signals came up on the MATLAB plots. A lot of thought went into figuring out why none of the signals were appearing.  A lab fellow suggested that an oscilloscope should be used to map out the signal and check its amplification by using the function generator.  After fiddling around with the equipment for a while, the lab period ended. A meeting with DJ, the advisor, was set up in order to figure out the source of the problem. The first problem was that the 2 data acquisition codes were saved under the same script and they should not have been. One of them was merely a practice to understand the commands in the real time code, and the other was the actual real time readings. Because they were both being run at the same time, it did not work. 

            After separating them, the signals still did not work. This occurred because the incorrect ports were specified in the MATLAB code, which was a simple fix.  After this, the signals were appearing on the MATLAB plots, but instead of being centered at 0 volts, all of the signal was occurring around 9 volts. This could be because such a large gain was used and a little noise from the amplification was amplified as well. Also, the electrodes noises were probably amplified a lot. This causes a problem for reading the signals, which prohibits the signals from being useful in the MATLAB code. Because of this, the goal for the following week is to install a capacitor at the end of the electrode input wires in order to remove the DC signal. This will hopefully correct the signals and put them down around the 0 volt range.