IR Sensor only sensing when IR Emitter moves

Other Hardware General Electronics
1

I am trying to make a photoelectric sensor using an IR emitter and an IR sensor.
Both are from the same brand and are compatible with each other, however, I constantly get a value of ca. 0.9 (should get 0 if it detects light) when holding the emitter right in front of the sensor. When I move the sensor away, it gives a value of 0.7, which I can work with.
Does anyone know how this happens and/or how I can fix it?
Thank you in advance.

2

Please post a schematic and your code, in code tags.

3

Using Python 3.9 with pyfirmata:

import pyfirmata
import time

try:
    board = pyfirmata.Arduino('/dev/cu.usbmodem1101')
except pyfirmata.serial.serialutil.SerialException:
    board = pyfirmata.Arduino('/dev/cu.usbmodem101')

it = pyfirmata.util.Iterator(board)
it.start()

board.digital[12].write(1) # signal for emitter
board.digital[13].write(1) # power for emitter and sensor

board.analog[0].enable_reporting() # input of sensor

a_0 = board.get_pin('a:0:i')

try:
    while True:
        board.digital[12].write(1)
        board.digital[13].write(1)
        print(a_0.read())
        time.sleep(0.1)
except (KeyboardInterrupt, OSError, SystemError): 
    pass
finally:
    board.digital[12].write(0)
    board.digital[13].write(0)

IMG_1587
IMG_15871827×1018 339 KB

4

Is that an IR detector/decoder that is used with an IR remote control. If so, then it may not be made to sense a steady signal, only a changing signal like the modulated signal from an remote control. You may need to modulate the signal from the emitter. 38KHz is a popular modulation frequency. And, even then, it may not work as the 38KHz frequency is further modulated to carry the information from a remote.

See this page.

5

No, it's just a sensor, which is compatible with the emitter. Both the frequencies are at 37,8 kHz.

6

Your schematic shows the emitter driven by the battery. Is the schematic not accurate?

7

It's a simplified version. The power comes from the arduino

8

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