def pbhubAnalogRead(pbhub, pbhub_address):
        data = 0
        max_val = 30
        min_val = 750
        for i in range(0, 10):
            newdata = 750 - pbhub.analogRead(pbhub_address)
            data += newdata
            if newdata > max_val:
                max_val = newdata
            if newdata < min_val:
                min_val = newdata
        data -= (max_val + min_val)
        data >>= 3
        return round(max(1024 * data / 750, 0), 2)

pbhub = unit.get(unit.PBHUB, unit.PORTA)
light = pbhubAnalogRead(pbhub, 0x01)

The magic number min_val I got by pressing my finger on the light sensor (blocking all the light from entering) and reading the analog value. The value 750 seems to be the minimum value the light sensor would emit. The number max_val I got by pointing a strong light at the sensor, it seems to be the maximum value the sensor emits. The min max values are mixed up because it measures the resistance and decreasing resistance means increasing light intensity. Using this method I get values that are somewhat similar to what I get by connecting the Light unit to PortB directly.

If anyone knows how this should be done properly, please let me know!

@ajb2k3 Yes, kind of. I have tested what the Light unit does for increasing values of self.adc.readraw() it will output decreasing values. This inversion is missing when reading directly from PbHUB .

class Light:
    @staticmethod
    def analogValue(value):
        data = 0
        max = 0
        min = 4096
        for i in range(0, 10):
            newdata = 4095 - value
            data += newdata
            if newdata > max:
                max = newdata
            if newdata < min:
                min = newdata
        data -= (max + min)
        data >>= 3

        return round(1024 * data / 4095, 2)


print(400, Light.analogValue(400))  # 400 923.98
print(500, Light.analogValue(500))  # 500 898.97
print(600, Light.analogValue(600))  # 600 873.96
print(700, Light.analogValue(700))  # 700 848.96
print(800, Light.analogValue(800))  # 800 823.95
print(900, Light.analogValue(900))  # 900 798.95

I am able to read values from the PbHUB like this:

pbhub = unit.get(unit.PBHUB, unit.PORTA)
earth = pbhub.analogRead(0x00)
light = pbhub.analogRead(0x01)

The problem is, that these values seem to be wrong. The lux value increases when it gets darker, similarly the earth unit says the earth gets dryer when it actually gets wetter. I think the problem is, that reading directly from PbHUB, the logic from the LIGHT.analogValue function is missing:

class Light:
    @property
    def analogValue(self):
        data = 0
        max = 0
        min = 4096
        for i in range(0, 10):
            newdata = 4095 - self.adc.readraw()
            data += newdata
            if newdata > max:
                max = newdata
            if newdata < min:
                min = newdata
        data -= (max + min)
        data >>= 3
        return round(1024 * data / 4095, 2)

This function seems to transform the data in a way that is missing when reading the value directly from PbHUB. My question is whether I do have to copy paste this logic or whether there is some way to reuse the LIGHT unit with PbHUB?

I would like to be able to do something like this:

pbhub = unit.get(unit.PBHUB, unit.PORTA)
earth = unit.get(unit.EARTH, pbhub.HUB0) # Not M5Stack API yet
light = unit.get(unit.LIGHT, pbhub.HUB1) # Not M5Stack API yet

# This should read the value correctly, using the `LIGHT.analogValue` logic
print(earth.analogValue())
print(light.analogValue())