Austin Milford-Rosales
Week 4
This week, I ended up spending a decent amount of time finishing work on the design review document. However, my primary goal was to test the functionality of the sensors and to try and develop the circuit for an individual square. The datasheet had two separate suggested designs that either involved a single capacitor or two capacitors and a resistor. I started off with the simpler one since if it works, then I won’t have to do as much soldering for the two boards. Since Chris is still working with the ADC, I used an arduino uno with analog pins to read output from the sensor, and went with the more basic circuit initially. It was able to output clear values to the serial monitor, distinguished between polarities as advertised, and when I placed a magnet in an adjacent spot (like where an adjacent square would be), the serial output indicated an output from the sensor around an order of magnitude less than when the magnet was directly above the sensor. It was ranging on a scale from around 100 to 500, and the sensor is supposed to output between 0 and 2 volts. As a result, although I now know the relative differences between various levels of output from the sensor based on different magnet placements, I still do not know the total voltage outputs based on magnet placements, and will try and have that determined by next week. I am very glad that the magnet does seem to work well, I was very concerned last week that I had made a critical mistake.
Over the course of the next two weeks, I am hoping to get more work done on designing the chained sensors so that I we can test multiple sensors with the ADC. Initially, that will just involve a few sensors on a breadboard, but hopefully I can design a more expansive test to go through before it comes time to actually solder the pieces together. I also need to spend some time with the ADC datasheet and the mux datasheets to make sure that I know the appropriate voltage levels they can take in, since I don’t want to blow out any components. I am roughly half a week behind right now, and hope to catch up over the next week or so. I have the basic circuit working, but until Chris and I get the ADC and the pi working together, I am uncertain how much more of what I can do with the Arduino will translate to the final project with the pi.