7 Photosensitive gesture

Photosensitivity and gesture detection

photosensitive sensor

Careful students may have found, in the bpibit board above two such things, yes, these two things are photosensitive sensor. It is a light-sensitive sensor that, through a sampling circuit, converts the intensity of light into the magnitude of the voltage.

Its model is PTSMD021 click to learn more

Get the intensity of the light

There is a light module in the firmware. We can easily get the light intensity by calling the function in this module.

sample code

import light
from time import sleep_ms
R = light.Intensity(39)
L = light.Intensity(36)
while True:
   print('R=',R.read())
   print('L=',L.read())
   sleep_ms(1000)

• To use the module of light, we first need to import this module, which can be imported by import light. Similarly, we need a delay function so we should import the function sleep_ms().
• What do light.Intensity(39) and light.Intensity(36) mean? it actually doing here is initializing the photosensitive sensor
• But why 36 and 39? Well, that's a question that we'll save for the last part of the course for you to fill in, which you probably don't understand right now.
• After the initialization is complete, we can call the read() function to get the light intensity. The read() function returns a value of 0-1000, which indicates the current approximate light intensity
• We can now print out the data serial port