Rewrite of PID according to https://hackmd.io/IACbwcOTSt6Adj3_F9bKuw PID implementation.
To migrate:
- TEC+/- pin polarity has to be reversed.
- Some saved settings might be wiped upon flashing of new firmware, back up settings before upgrade
- Min / Max integral parameters no longer exist
- kp, ki, kd will likely need to be retuned
The software has been tested on hardware with good temperature control stability.
Reviewed-on: M-Labs/thermostat#68
Co-authored-by: topquark12 <aw@m-labs.hk>
Co-committed-by: topquark12 <aw@m-labs.hk>
Flipped error calculation method to correct behavior of kP and kI terms.
Added anti integral windup to integral handling.
Changed how the i and integral term is calculated, to prevent old kI settings from affecting the current i term calculation when kI is being tuned. Especially noticable when kI is set from a non-zero value to zero.
Co-Authored-By: topquark12 <aw@m-labs.hk>
Co-Committed-By: topquark12 <aw@m-labs.hk>