TypeError: unorderable types: NoneType() > int()

[unique1o1]

i'm trying to turn OFF and ON an LED according to the data from a LDR using this code:

from pyfirmata import Arduino, util
board=Arduino('/dev/ttyACM1')
led=board.get_pin('d:13:0')
ldr=board.analog[0]
it = util.Iterator(board)
it.start()
board.analog[0].enable_reporting()
x=board.analog[0].read()
if x>20:
    led.write(0)
else:
    led.write(1)

and it gives me this error TypeError: unorderable types: NoneType() > int()

whereas using the board.analog[0].read() in a python shell give a float. What am i doing wrong here?

[Monstamac]

I have the same issue. The type comes up as <type 'NoneType'> and I struggle to cast it to anything.

[tino]

@unique1o1 I suspect the error is thrown on the if x>20: line?

Use if x and x > 20: instead. read() can return None in the beginning when there aren't any reads yet.

[JervisNW]

Try print(x) after x=board.analog[0].read()

I had the same problem and that is how a solved it.

from pyfirmata import ArduinoMega, util, pyfirmata import time

LED = 3 arduino = ArduinoMega("COM3")

arduino.analog[7].mode = pyfirmata.INPUT

it = util.Iterator(arduino) it.start() time.sleep(0.05) arduino.analog[7].enable_reporting() i=0 while(True): sensor=arduino.analog[7].read() print(sensor) if i>100 and sensor > 0.500: arduino.digital[LED].write(1) else: arduino.digital[LED].write(0) i=i+1