The Steinhart-Hart equation was changed in code long ago to the
B-parameter equation. Rename references to it and the interface
accordingly. The `s-h` command is now `b-p`.
The reason the name "B-Parameter" equation was chosen over
"Beta-Parameter" was due to its easier searchability.
Current limit pins are driven by PWM inputs to the MAX1968 driver, but
this is an implementation detail, and should not be exposed in the form
of the command interface. Rename "pwm" to "output" in all instances.
See M-Labs/thermostat#62 (comment).
Effectively flips all values related to the directionality of current
through the TEC, including current maximums. The reversed status is
stored in the flash store and will be loaded on reset once saved.
The command is "pwm <ch> polarity <normal/reversed>", where the "normal"
polarity is indicated by the front panel markings.
This is needed for IDC cable connections to the Sinara 5432 DAC
"Zotino", since the TEC pins of the 10-pin connector on the Thermostat
and Zotino have opposite polarities.
As the report mode command breaks the send-receive architecture model of
the command interface, and is deemed an anti-feature, making clients
difficult to write, remove it from the firmware entirely.
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>
