justin
6c1ee0c81d
obdcore additions (all standard SAE J1979, vehicle-agnostic, hardware-free tested): - obdservices.py: decode_vin (Mode 09), decode_readiness (Mode 01 PID 01 I-M monitors + MIL + DTC count, spark/diesel monitor sets), freeze-frame PID set. - link.py: ElmLink.read_vehicle_info (VIN/cal/ECU), read_readiness, read_freeze_frame. - trip.py: TripComputer (MAF-based MPG + trip totals) and PerformanceMeter (0-60 / 1/4-mile with launch detection). - mock.py: speed/MAF/readiness + service stubs for GUI mock mode. - tests/test_services.py: VIN, readiness bit decode, trip math, 0-60/quarter. Co-Authored-By: Claude Opus 4.8 (1M context) <noreply@anthropic.com> Claude-Session: https://claude.ai/code/session_016yT89n4zR4qbrySoSiEyZs
120 lines
3.9 KiB
Python
120 lines
3.9 KiB
Python
"""Trip computer + performance timers (computed from live data, no serial).
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TripComputer estimates fuel economy and trip totals from vehicle speed (km/h)
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and MAF (g/s) -- the same MAF-based estimate Torque/etc. use. PerformanceMeter
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measures 0-60 mph and 1/4-mile times, auto-detecting a launch from a near-stop.
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Both are fed time-stamped samples and are unit tested without hardware.
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"""
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KMH_PER_MPH = 1.609344
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GAS_AFR = 14.7 # stoichiometric air:fuel for gasoline
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GAS_G_PER_GAL = 2835.0 # ~6.25 lb/gal
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def _gph(maf_gps, afr=GAS_AFR, g_per_gal=GAS_G_PER_GAL):
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return (maf_gps / afr) * 3600.0 / g_per_gal
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class TripComputer:
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def __init__(self, afr=GAS_AFR, g_per_gal=GAS_G_PER_GAL):
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self.afr, self.g_per_gal = afr, g_per_gal
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self.reset()
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def reset(self):
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self.dist_km = 0.0
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self.fuel_gal = 0.0
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self.moving_s = 0.0
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self.elapsed_s = 0.0
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self._t = None
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def update(self, t, speed_kmh, maf_gps):
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if self._t is None:
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self._t = t
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return
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dt = t - self._t
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self._t = t
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if dt <= 0 or dt > 5: # ignore gaps / first sample
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return
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self.elapsed_s += dt
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if speed_kmh:
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self.dist_km += speed_kmh * dt / 3600.0
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if speed_kmh > 1.0:
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self.moving_s += dt
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if maf_gps:
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self.fuel_gal += _gph(maf_gps, self.afr, self.g_per_gal) * dt / 3600.0
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def instant_mpg(self, speed_kmh, maf_gps):
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if not speed_kmh or not maf_gps:
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return 0.0
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gph = _gph(maf_gps, self.afr, self.g_per_gal)
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return (speed_kmh / KMH_PER_MPH) / gph if gph > 0 else 0.0
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def avg_mpg(self):
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miles = self.dist_km / KMH_PER_MPH
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return miles / self.fuel_gal if self.fuel_gal > 0 else 0.0
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def stats(self):
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return {
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"distance_mi": round(self.dist_km / KMH_PER_MPH, 2),
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"fuel_gal": round(self.fuel_gal, 3),
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"avg_mpg": round(self.avg_mpg(), 1),
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"elapsed_s": round(self.elapsed_s, 1),
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"moving_s": round(self.moving_s, 1),
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}
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class PerformanceMeter:
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"""0-60 mph and 1/4-mile timers. A run starts when the car pulls away from a
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near-stop and ends at the 1/4 mile or when it stops; best times are kept."""
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QUARTER_M = 402.336
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def __init__(self):
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self.best_0_60 = None
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self.best_quarter = None
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self.last_0_60 = None
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self.last_quarter = None
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self._reset_run()
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def _reset_run(self):
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self._running = False
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self._t0 = None
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self._dist_m = 0.0
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self._last_t = None
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self._stop_t = None
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self._did60 = False
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def update(self, t, speed_kmh):
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if speed_kmh is None:
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return
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mph = speed_kmh / KMH_PER_MPH
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if not self._running:
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if mph < 1.0:
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self._stop_t = t # parked, ready to launch
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elif self._stop_t is not None:
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self._running = True # launch detected
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self._t0 = self._stop_t
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self._dist_m = 0.0
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self._last_t = t
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self._did60 = False
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return
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dt = t - self._last_t
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self._last_t = t
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if dt <= 0 or dt > 5:
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self._reset_run()
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return
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self._dist_m += (speed_kmh / 3.6) * dt
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if mph >= 60 and not self._did60:
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self._did60 = True
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self.last_0_60 = round(t - self._t0, 2)
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if self.best_0_60 is None or self.last_0_60 < self.best_0_60:
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self.best_0_60 = self.last_0_60
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if self._dist_m >= self.QUARTER_M:
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self.last_quarter = round(t - self._t0, 2)
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if self.best_quarter is None or self.last_quarter < self.best_quarter:
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self.best_quarter = self.last_quarter
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self._reset_run()
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elif mph < 1.0:
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self._reset_run()
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