Gain 0.5 inaccessible due to CV structure?

[bobthechemist]

adafruit_as7341.Gain.is_valid(0.5) returns False even though 0.5 is valid (see here). Gain inherits CV which limits the 2nd and third positions of the tuple to INT (see here) which is - I think - the cause of the issue. adafruit_as7341.Gain.is_valid(0) returns True, so 0.5 has probably been rounded down when the Gain class is created.

Setting gain to 0 doesn't stop functionality:

import board
import adafruit_as7341
from time import sleep

i2c = board.I2C()
s = adafruit_as7341.AS7341(i2c)

s.led = True

# first reading is usually trash
junk = s.channel_480nm
sleep(0.5)

for g in [0, 1, 2, 4, 8]:
    s.gain = g
    sleep(0.5)
    print(f"gain:{g}, channel 480 nm: {s.channel_480nm}")

s.led = False

outputs the following

gain:0, channel 480 nm: 18
gain:1, channel 480 nm: 36
gain:2, channel 480 nm: 70
gain:4, channel 480 nm: 249
gain:8, channel 480 nm: 4268

Other objects rely on CV, but they all seem to have INT in the third slot of the tuple, so perhaps a simple return int(value) here might do the trick?

[caternuson]

You generally shouldn't need to call Gain.is_valid() directly. That's used internally to validate the setting.

It's probably worth updating the simpletest example to show a gain setting since the syntax is not super obvious. But the general idea is to use the const values defined in the Gain class. Do not use integer or float literals.

ex:

s.gain = adafruit_as7341.Gain.GAIN_0_5X

[bobthechemist]

You generally shouldn't need to call Gain.is_valid() directly. That's used internally to validate the setting.

It's probably worth updating the simpletest example to show a gain setting since the syntax is not super obvious. But the general idea is to use the const values defined in the Gain class. Do not use integer or float literals.

ex:

s.gain = adafruit_as7341.Gain.GAIN_0_5X

Agreed - I toyed with Gain.is_valid() for debugging purposes. My issue arose when creating an application where the end user is able to set and change the colorimeter gain. Having a user remember GAIN_0_5X rather than a simple number is where I ran into problems (that I realize are readily solvable).