Pull the analog value of a photoresistor sensor and display it on your computer
Photoresistor output connected to pin PF0 on a Teensy 2.0.
This code was tested for Mac using the following command in terminal: screen /dev/tty.usbmodem12341. The TTY name may be different on your machine.
USB serial on Teensy for Windows and Mac: https://www.pjrc.com/teensy/usb_serial.html