I have been experimenting DA7218 ALC features on the eval board with Canvas. So far there are some erratic behaviors I could not reason with.
I used a tone generator as a source.
If the input to eval board is audio jacks, ALC behaves fine.
If the input to eval board is real sound from a speaker captured through the LP mic, ALC has a weird behavior describes as follows:
min set to -15dBfs, max set to -5dBfs, using hybrid mode.
when noise level is set below -67dBfs, ALC behaves fine
when nose level is set > around 60dBfs, ALC fails to function! I turned up and down the volumn, no auto adjustment on the level as observed previously.
What's going on? Why a slightly higher noise level cripples ALC?