Ashley's Week 11 Report

This Week: Andrew and I met up and decided to work on reading the raw values off the Apparent and Active Energy registers.  We took out the calibration steps that we had started to use and only added in a few register settings that we needed to make these registers begin accumulating values.  Our apparent energy was looking stable in the 10 million magnitude, but active was jumping around quite a bit.  Andrew decided to take out the digital isolator since he had built his own isolators on the circuit board.  This made a huge impact on our readings.  We were getting consistent values for both apparent and active energy and they were significantly lower (in the hundreds).  We collected the average values with 1 light bulb, 2 light bulbs, and 3 light bulbs.  We made a scatter plot in Excel containing the three points for both the active and the apparent energy.  Then we ran a linear regression to find a fitted line.  The R squared values were 1 and .99999 so that gave us proof that the relation between the actual energy output and that read from from the chip were linear.  We began applying the equations to the values read from the registers to see how close it would display to the correct value.  You can see our data below.

Next Week:  Kevin and I am meeting up today to work on passing the active and apparent energy values.  We have only sent values that fit into 1 byte in the past so we may need to do some tweaking so that he can read values larger than that.  Once we're able to pass him the numbers, we will start collecting the data points from his computer and redo the equations for calculating the correct active and apparent energy.  When Andrew and I first added in the equations before printing the two values, we saw that the numbers fluctuated a bit.  We realized that adding in those few lines of code slightly delayed things until the next read command, therefore allowing the energy to accumulate to a slightly higher value than we calculated for.  So keeping the old equations as a "place holder" in the program will allow us to read the raw values that we want and use them to figure out the correct parameters in the equations.

Overall we are feeling like we've made some great progress and feel more comfortable about the direction we are going.

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