HTM(a)A Arch Section Group Work
Input Devices
The group assignment was: to probe an input device's analog levels and digital signals.
For this week, we probed a phototransistor using an oscilloscope.
The board was programmed to analogRead() the signal of the phototransistor which returns a value between 0 - 1023
depending on how bright it is. It then does an analogWrite() to send this value to the RX pin.
We connected the ground probe to the ground FTDI pin and the positive probe to the RX FTDI pin. Here is an image showing the setup and readings:
We see from the oscilloscope that the recorded signal has an amplitude of 5V and the period of the narrowest band to be ~0.1ms.