bits and pieces

import pyfirmata
 
# Time (approx. seconds) to get to the maximum/minimum
DURATION = 5
# Numbers of steps to get to the maximum/minimum
STEPS = 10 
 
# Creates a new board and define the pin
board = pyfirmata.Arduino(/dev/ttyACM0)
digital_0 = board.get_pin('d:11:p')
 
# Waiting time between the 
wait_time = DURATION/float(STEPS)
 
# Up
for i in range(1, STEPS + 1):
    value = i/float(STEPS)
    digital_0.write(value)
    board.pass_time(wait_time)
 
# Down
increment = 1/float(STEPS)
while STEPS > 0:
    value = increment * STEPS
    digital_0.write(value)
    board.pass_time(wait_time)
    STEPS = STEPS - 1
 
board.exit()