Scripts/C/Java for the Raspberry Pi server.


Some key files:

powermng.cpp
    Manages power for the RPi based on battery SoC and grid state, eg
    dumping some excess power to a load moved off-grid at optimal times.

ssmppt15l-modbus.cpp
    Reads some key parameters from the SS-MPPT-15L solar controller.

README.txt
    This file.

snapshots/
    Code snapshots by date.

tests/
    Unit tests of key elements of functionality.

Pending ideas:
  * Break out templated core algos and unit test with gtest.
  * Improve 's' by not preventing dumping at times of day when import likely.
  * Set temp adjusted margin to reflect coldest forecast temp during next
    12--24h to retain adequate margin overnight when temp is falling.

Some key updates:

2021-03-26: add A1V raw primary array voltage (mV) to end of logged stats.
2020-12-05: if many days since FULL, eg mid-winter, only dump when red or VFULL.
2020-06-27: -n option now also suppresses adjusing flags and other priv ops.
2020-06-26: folding in support for Expander Pi on RPi3B.
2018-09-11: added extra "significant grid-tie generation" guard to 's'.
2018-09-01: adjusting thresholds to improve use of available capacity.
2018-08-27: prevent dumping while SoC low and grid-tie exporting.
2018-07-08: allowing continuous dumping if battery SoC > 95%.
2018-06-22: removing aggressive dump lockout for day after VLOW (dip).
2018-06-21: adjusting to potentially allow continuous dumping.
2018-06-19: protective reserve for poor forecast now USoC %age.
2018-06-18: allowing very full battery to dump a little, even mid-winter.
2018-06-17: rejigged and unit-tested LA impedance and USoC algos.
2018-06-16: adding Eclipse support (to enable laptop unit test runs).
2018-06-14: adding GTest unit test support.
2018-06-10: adding 'Usable Charge' percentage to log output.
2018-06-10: slightly keener to keep load off grid (by dumping).
2018-06-08: rearranging dump margin calc since currently far too dump averse.
2018-06-06: cap threshold for dumping to 'resting full' V when discharging.
2018-05-23: only avoid dumping to grid when 'deep green', ie no storage draw.
2018-05-23: overnight voltage too high at ~12.8V so thresholds reduced.
2018-02-16: pushing up dump margin from 50mV to 150mV min to avoid wee hours VL.
2018-01-08: pushing up dump margin from 3 to 4 days nominal.
2018-01-08: pushing up extra margin in absence of good forecast / recent VLOW.
2018-01-05: temperature compensation -15mV/C to keep out of VLOW unnecessarily.
2017-12-30: reduced setpoint temperature compensation to -18mV/C.
2017-12-16: fixed direction of temp compensation and it is now always applied.
2017-12-16: prevent dumping ('L') if not long enough since last VLOW.
2017-11-05: added 'S' low SoC branch to prevent dumping.
2017-11-05: added 'long time since FULL' flag, initially gating 'N' status.
2017-10-21: now computing effective SoC from compensated B1 voltage.
2017-10-20: VHIGH now not active until charger reports absorption phase reached.
2017-10-01: tuned LOW/VLOW thresholds to be slightly less conservative.
2017-09-23: ondemand sampling_rate and sampling_down_factor now controlled too.
2017-09-23: ondemand governor threshold adjusted at VLOW boundary not LOW.
2017-09-18: LOW and VLOW thresholds adjusted upwards to avoid sulphation.
2016-11-29: constexpr applied liberally.
2016-11-29: tweaking temperature compensation to battery impedance/sag.
2016-11-12: applying temperature compensation to battery impedance/sag.
2016-10-30: added -E to ssmppt15l-modbus to help gather entropy.
2016-10-01: tweaked looping to ease collection of high-res sample with -nl.
2016-09-25: B1 temperature logging and compensation.
2016-09-24: created BATT1_MINUSAGE_mV_per_day; tiered 'e' dump triggers by days.
2016-09-17: attempt to suppress dump oscillation with tweaked thresholds.
2016-09-11: commented out most of B2 (Li) code.
2016-09-11: dump margin and sag calcs now dynamic with load compensation.
2016-09-10: more cautious after reboot in reliance on last-VHIGH flag timing.
2016-09-10: added live calc of implied supply impedance to RPi.
2016-09-09: made time since VHIGH determinant of less aggressive dumping.
2016-09-07: prioritised dump load triggers further.
2016-09-01: dumping less aggressive if battery not FULL for several days.
2016-09-01: moving locking to mbacess to be shared by the command-line tools.
2016-08-30: encouraging dump is battery > 'medium' and grid not 'green'.
2016-08-28: added FULL state (>=VH and battery in float) and flags.
2016-08-25: split out separate mbaccess.cpp wrapper.