Week 10:

Input Devices

This week I learnt how to measure data from a sensor. This was the most frustrating week for me and the week of silly mistakes. I made a Capacitive sensor that takes body capacitance as an input. I redrew the step response board and used python serial to visualize the data from the sensor. In coming weeks I want to try other sensors as well.


photo
SAM_0274
Oscilloscope
SAM_0275



Redrawing the Stepreponse hello load board

I used eagle to redraw Neil's stepresponse board to get a sense of how it works. I added a chip holder so that I could program the chip and use it again to make handcrafted conductive fabric circuit without the connectors. In my board design there were pads to attach the chip holder.

Screen Shot 2013-11-13 at 6.30.55 AM Screen Shot 2013-11-13 at 6.32.37 AM


Milling and stuffing the board

Adding the chip holder was slightly tricky. I didn't have Via on my board and I soldiered the chip from the back. Later I realized that I should have soldiered it from the top. To fix this I resoldered the chip holder again from the side. Also there was no connection from SCK to PB2. It was in my schematic but I guess I missed the connection while routing. So I used a thin wire to fix it.

SAM_0272 SAM_0274


Programming the board and measuring data from the sensor



Screen Shot 2013-11-13 at 6.05.36 AM


Measuring Data from the sensor