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Class Mar 28 Assignment

I'm really eager to get going with the step-resonce boards.

This would be in ideal (hopefully low-power as well) to do NFC communication between battery-powered boards.

So for this week i'm going to make a board that will be battery powered (3v coin-cell)

Level shifter for ftdi cable? doable with mosfets available in the fablab?

The Step-Responce board (tx-rx)

I took a while to comprehend what was doing what.

things became a lot more clear after hooking the board up to an oscilloscope. So 1 line/surface is being charged and discharged (transmitter) from the microcontroller.

This transition is also seen on the second surface (receiver). This charge is being pulled in the direction of the other charge and then being pulled back towards the 2.5 volts.

For this first attempt i've used 2 pieces of copper that looked nice (bullseye) but now i'm wondering if this is actually the right way to do this kind of step-responce.

I also want to try the load example to see how that resonds in the noisy environments i'm usually in. :)

Above, both the loading and the transmit receive bords i made for this excersize.

With the TX-RX-board i actually had the calibration problem. Avrdude has a neat solution for this (the -O option), but unfourtunately the usbTiny doesn't support this. Fortunately i have got a logic analyser, and run windows, so i found that the communication was actually at 10200 bps, so i adapted the .py and got readable values. :)

The FTDI converters actually perform fine on any baud rate you put them (integers only ofcourse) although this does not seem to be as straightforward on every OS.

In class Neil suggested i could actually use the fingered sensor as an accellerometer (actually an deflection sensor.)