Remove floating point calculation from ac_dimmer ISR

[Azimath]

What does this implement/fix?

PR#3494 added code to linearize the RMS power output of the ac_dimmer relative to the output state. Doing so introduced an acos into the ISR, which most of the time works, but some race condition exists that causes this call to throw an exception when doing stuff like OTA, setting a new value in home assistant, or sometimes it just keeps working (depending on what version of ESPHome you're running and your luck).

The RMS power linearization only needs to be computed when a new state is written, as it doesn't vary cycle to cycle. This PR moves the acos function outside the ISR into the write_state function where it shouldn't cause problems.

The original PR was considered breaking because it might change how gamma is perceived on some lights. The linearization previously applied only to leading dimmers, while now it applies to both, so it might change how gamma is perceived on trailing dimmers.

Types of changes

• Bugfix (non-breaking change which fixes an issue)
• New feature (non-breaking change which adds functionality)
• Breaking change (fix or feature that would cause existing functionality to not work as expected)
• Other

Related issue or feature (if applicable): fixes 3509

Test Environment

• ESP32
• ESP32 IDF
• ESP8266

Example entry for config.yaml:

output:
  - platform: ac_dimmer
    id: dimmer1
    gate_pin: 
      number: GPIO13
      inverted: true
    zero_cross_pin: GPIO12
    min_power: 0.2
    zero_means_zero: true

Checklist:

• The code change is tested and works locally.
• n/a Tests have been added to verify that the new code works (under tests/ folder).

If user exposed functionality or configuration variables are added/changed:

• Documentation added/updated in esphome-docs.

[probot-esphome]

Hey there @glmnet, mind taking a look at this pull request as it has been labeled with an integration (ac_dimmer) you are listed as a code owner for? Thanks!
_{^{(message by CodeOwnersMention)}}

[glmnet]

@josephdouce can you please review this?

[josephdouce]

Will do Kind Regards Joseph Douce BEng (Hons) MIET

…

On Mon, 5 Sept 2022, 14:48 Guillermo Ruffino, ***@***.***> wrote: @josephdouce <https://github.com/josephdouce> can you please review this? — Reply to this email directly, view it on GitHub <#3770 (comment)>, or unsubscribe <https://github.com/notifications/unsubscribe-auth/AAN74Y3ASXJNX3LWCK4UXILV4X22RANCNFSM6AAAAAAQEVGDWM> . You are receiving this because you were mentioned.Message ID: ***@***.***>

[Azimath]

@josephdouce Have you had a chance to look at this yet? -Azimath

…

On Mon, Sep 5, 2022, 11:52 AM joseph douce ***@***.***> wrote: Will do Kind Regards Joseph Douce BEng (Hons) MIET On Mon, 5 Sept 2022, 14:48 Guillermo Ruffino, ***@***.***> wrote: > @josephdouce <https://github.com/josephdouce> can you please review this? > > — > Reply to this email directly, view it on GitHub > <#3770 (comment)>, > or unsubscribe > < https://github.com/notifications/unsubscribe-auth/AAN74Y3ASXJNX3LWCK4UXILV4X22RANCNFSM6AAAAAAQEVGDWM > > . > You are receiving this because you were mentioned.Message ID: > ***@***.***> > — Reply to this email directly, view it on GitHub <#3770 (comment)>, or unsubscribe <https://github.com/notifications/unsubscribe-auth/AAYPHF2NDX2NVW3HNVRNSK3V4YJLZANCNFSM6AAAAAAQEVGDWM> . You are receiving this because you authored the thread.Message ID: ***@***.***>

[josephdouce]

Sorry for the delay, can't see any problem here, I was looking to do something similar myself but didn't get chance. Good improvement moving the calculation to cover all edge types too. Kind Regards Joseph Douce BEng (Hons) MIET

…

On Tue, 13 Sept 2022, 19:06 Azimath, ***@***.***> wrote: @josephdouce Have you had a chance to look at this yet? -Azimath On Mon, Sep 5, 2022, 11:52 AM joseph douce ***@***.***> wrote: > Will do > > Kind Regards > > Joseph Douce BEng (Hons) MIET > > On Mon, 5 Sept 2022, 14:48 Guillermo Ruffino, ***@***.***> > wrote: > > > @josephdouce <https://github.com/josephdouce> can you please review > this? > > > > — > > Reply to this email directly, view it on GitHub > > <#3770 (comment) >, > > or unsubscribe > > < > https://github.com/notifications/unsubscribe-auth/AAN74Y3ASXJNX3LWCK4UXILV4X22RANCNFSM6AAAAAAQEVGDWM > > > > . > > You are receiving this because you were mentioned.Message ID: > > ***@***.***> > > > > — > Reply to this email directly, view it on GitHub > <#3770 (comment)>, > or unsubscribe > < https://github.com/notifications/unsubscribe-auth/AAYPHF2NDX2NVW3HNVRNSK3V4YJLZANCNFSM6AAAAAAQEVGDWM > > . > You are receiving this because you authored the thread.Message ID: > ***@***.***> > — Reply to this email directly, view it on GitHub <#3770 (comment)>, or unsubscribe <https://github.com/notifications/unsubscribe-auth/AAN74YYPPRUDWXN6W265BOLV6C7CBANCNFSM6AAAAAAQEVGDWM> . You are receiving this because you were mentioned.Message ID: ***@***.***>