PsychoPy-Arduino Exercise #1
Calibrating the Arduino light sensor via a Builder project

Intro Routine
-------------

Create an introductory routine to display instructions and prompt for a keyboard
response before continuing.  Add the following custom code to the routine:

Custom_code|Begin Experiment tab

	#Initialize serial connection to Arduino
	import serial
	com_port = "COM18"   #Windows USB serial port address
	#com_port = "/dev/cu.usbmodem14101"  #Mac USB serial port address
	try:
		arduino=serial.Serial(com_port,baudrate=115200,timeout=0.015)
	except:
		print("Unable to open serial port:", com_port)
		
Black Calibration Routine
-------------------------
Next, create a routine to fill the screen with a black rectangle.  Set the duration
of the rectangle to infinity.  It will be terminated via custom code (see below)
when the Arduino microcontroller finishes the requested Black Level calibration 
operation.

Custom_code|Each Frame tab:

	#request Arduino BLACK level baseline scan at Routine start
	if frameN == 2:
		arduino.write(bytes('b','utf-8'))

	#service Arduino acknowledgment that scan has started
	if frameN == 6:
		if arduino.in_waiting > 0:
			serial_input = arduino.readline() #service serial input buffer
			print("BLACK_CAL_ACK:",serial_input)

	#exit Routine when BLACK level scan completed
	if frameN > 6:
		if arduino.in_waiting > 0:
			serial_input = arduino.readline()  #service serial input buffer
			print("BLACK_CAL_RESULT:", serial_input)
			continueRoutine = False  #exit Routine

White Calibration Routine
-------------------------
Next, create a routine to fill the screen with a white rectangle.  Set the duration
of the rectangle to infinity.  It will be terminated via custom code (see below)
when the Arduino microcontroller finishes the requested White Level calibration
operation.

Custom_code|Each Frame tab:

	#request Arduino WHITE level baseline scan at Routine start
	if frameN == 2:
		arduino.write(bytes('w','utf-8'))

	#service Arduino acknowledgment that scan has started
	if frameN == 6:
		if arduino.in_waiting > 0:
			serial_input = arduino.readline() #service serial input buffer
			print("WHITE_CAL_ACK:",serial_input)

	#exit Routine when WHITE level scan completed
	if frameN > 6:
		if arduino.in_waiting > 0:
			serial_input = arduino.readline()  #service serial input buffer
			print("WHITE_CAL_RESULT:", serial_input)
			continueRoutine = False  #exit Routine

Custom_code|End Experiment tab:

	#terminate serial connection to Arduino
	arduino.close()

Note:
After running the PsychoPy Builder experiment, check the PsychoPy Runner console for
the feedback messages generated by the 'print' statements in the custom code.