Files
mppt-testbench/testbench/tuner.py
grabowski 1c41910c1e Add STM32 tuning integration and rewrite README with step-by-step guide
- stm32_link.py: synchronous serial interface to STM32 debug protocol
  (ping, telemetry read/avg, param read/write, frame parser)
- tuner.py: automated tuning combining HIOKI + STM32 measurements
  (param sweep, deadtime optimization, multi-point sweep, CSV/plot output)
- CLI commands: stm32-read, stm32-write, tune-param, tune-deadtime
- README: complete step-by-step guide covering setup, sweeps, analysis,
  tuning, shade profiles, debug console, and parameter reference

Co-Authored-By: Claude Opus 4.6 <noreply@anthropic.com>
2026-03-12 16:52:09 +07:00

444 lines
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"""Automated tuning routines combining testbench instruments + STM32 link.
Uses the power analyzer (HIOKI) as ground truth for efficiency while
adjusting converter parameters via the STM32 debug protocol.
"""
from __future__ import annotations
import csv
import time
from dataclasses import dataclass, field
from pathlib import Path
from testbench.bench import MPPTTestbench, IDLE_VOLTAGE
from testbench.stm32_link import (
STM32Link, Telemetry, PARAM_BY_NAME, DT_BRACKETS,
)
@dataclass
class TunePoint:
"""One measurement during a tuning sweep."""
param_name: str
param_value: float
voltage_set: float
load_setpoint: float
load_mode: str
# HIOKI measurements (ground truth)
meter_pin: float = 0.0
meter_pout: float = 0.0
meter_eff: float = 0.0
# STM32 telemetry
stm_vin: float = 0.0
stm_vout: float = 0.0
stm_iin: float = 0.0
stm_iout: float = 0.0
stm_eff: float = 0.0
stm_vfly: float = 0.0
stm_etemp: float = 0.0
timestamp: float = field(default_factory=time.time)
class Tuner:
"""Combines MPPTTestbench + STM32Link for automated tuning.
Usage::
tuner = Tuner(bench, link)
results = tuner.sweep_param(
"dt_10_20A", start=14, stop=40, step=1,
voltage=60.0, current_limit=20.0,
load_mode="CP", load_value=300.0,
)
tuner.print_results(results)
"""
def __init__(
self,
bench: MPPTTestbench,
link: STM32Link,
settle_time: float = 3.0,
stm_avg_samples: int = 10,
):
self.bench = bench
self.link = link
self.settle_time = settle_time
self.stm_avg_samples = stm_avg_samples
def _measure(
self,
param_name: str,
param_value: float,
voltage: float,
load_value: float,
load_mode: str,
) -> TunePoint:
"""Take one combined measurement from HIOKI + STM32."""
point = TunePoint(
param_name=param_name,
param_value=param_value,
voltage_set=voltage,
load_setpoint=load_value,
load_mode=load_mode,
)
# HIOKI measurement
meter_vals = self.bench._wait_meter_ready(max_retries=10, retry_delay=1.0)
point.meter_pin = meter_vals.get("P5", 0.0)
point.meter_pout = meter_vals.get("P6", 0.0)
point.meter_eff = meter_vals.get("EFF1", 0.0)
# STM32 telemetry (averaged)
t = self.link.read_telemetry_avg(n=self.stm_avg_samples)
if t:
point.stm_vin = t.vin_V
point.stm_vout = t.vout_V
point.stm_iin = t.iin_A
point.stm_iout = t.iout_A
point.stm_eff = t.efficiency
point.stm_vfly = t.vfly / 1000.0
point.stm_etemp = t.etemp
return point
# ── Parameter sweep ──────────────────────────────────────────────
def sweep_param(
self,
param_name: str,
start: float,
stop: float,
step: float,
voltage: float,
current_limit: float,
load_mode: str = "CC",
load_value: float = 5.0,
settle_time: float | None = None,
) -> list[TunePoint]:
"""Sweep a single STM32 parameter while measuring efficiency.
Sets up the testbench at the given operating point, then steps
the parameter from start to stop, measuring at each step.
Returns list of TunePoints with both HIOKI and STM32 data.
"""
if param_name not in PARAM_BY_NAME:
raise ValueError(f"Unknown parameter: {param_name!r}")
settle = settle_time or self.settle_time
if step == 0:
raise ValueError("step cannot be zero")
if start > stop and step > 0:
step = -step
elif start < stop and step < 0:
step = -step
# Count steps
n_steps = int(abs(stop - start) / abs(step)) + 1
unit = "A" if load_mode == "CC" else "W"
print(f"Parameter sweep: {param_name} = {start}{stop} (step {step})")
print(f" Operating point: V={voltage:.1f}V, {load_mode}={load_value:.1f}{unit}")
print(f" {n_steps} points, settle={settle:.1f}s")
print()
# Set up testbench
self.bench.supply.set_current(current_limit)
self.bench.supply.set_voltage(voltage)
self.bench.supply.output_on()
self.bench.load.set_mode(load_mode)
self.bench._apply_load_value(load_mode, load_value)
self.bench.load.load_on()
# Initial settle
print(" Settling...")
time.sleep(settle * 2)
results: list[TunePoint] = []
val = start
n = 0
try:
while True:
if step > 0 and val > stop + step / 2:
break
if step < 0 and val < stop + step / 2:
break
# Write parameter
ack = self.link.write_param(param_name, val)
if not ack:
print(f" WARNING: No ACK for {param_name}={val}")
time.sleep(settle)
# Measure
point = self._measure(param_name, val, voltage, load_value, load_mode)
results.append(point)
n += 1
print(
f" [{n:>3d}/{n_steps}] {param_name}={val:>6.1f} "
f"HIOKI: Pin={point.meter_pin:7.1f}W Pout={point.meter_pout:7.1f}W "
f"EFF={point.meter_eff:5.2f}% "
f"STM32: EFF={point.stm_eff:5.1f}% T={point.stm_etemp:.0f}°C"
)
val += step
finally:
self.bench.load.load_off()
self.bench.supply.set_voltage(IDLE_VOLTAGE)
print(f"\n Load OFF. Supply at {IDLE_VOLTAGE:.0f}V.")
return results
# ── Deadtime optimization ────────────────────────────────────────
def tune_deadtime(
self,
dt_start: int = 14,
dt_stop: int = 50,
dt_step: int = 1,
voltage: float = 60.0,
current_limit: float = 20.0,
load_mode: str = "CP",
load_values: list[float] | None = None,
settle_time: float | None = None,
) -> dict[str, list[TunePoint]]:
"""Optimize deadtime for each current bracket.
For each deadtime bracket, sets a load that puts the converter
in that current range, then sweeps deadtime values to find the
optimum.
Args:
load_values: Load setpoints to test (one per DT bracket).
If None, auto-selects based on bracket midpoints.
"""
settle = settle_time or self.settle_time
if load_values is None:
# Auto-select load values targeting the middle of each bracket
# Using CP mode: power ≈ voltage × current
load_values = []
for _, _, i_lo, i_hi in DT_BRACKETS:
mid_i_A = (i_lo + i_hi) / 2 / 1000.0 # mA → A
target_power = voltage * mid_i_A * 0.4 # rough vout/vin ratio
load_values.append(max(10.0, target_power))
print("=" * 80)
print("DEADTIME OPTIMIZATION")
print(f" DT range: {dt_start}{dt_stop} (step {dt_step})")
print(f" V={voltage:.0f}V, I_limit={current_limit:.0f}A, mode={load_mode}")
print("=" * 80)
all_results: dict[str, list[TunePoint]] = {}
for i, (param_id, param_name, i_lo, i_hi) in enumerate(DT_BRACKETS):
load_val = load_values[i] if i < len(load_values) else load_values[-1]
unit = "A" if load_mode == "CC" else "W"
print(f"\n── Bracket: {param_name} ({i_lo/1000:.0f}-{i_hi/1000:.0f}A) "
f"@ {load_mode}={load_val:.0f}{unit} ──")
results = self.sweep_param(
param_name=param_name,
start=dt_start,
stop=dt_stop,
step=dt_step,
voltage=voltage,
current_limit=current_limit,
load_mode=load_mode,
load_value=load_val,
settle_time=settle,
)
all_results[param_name] = results
# Find and report best
if results:
valid = [p for p in results if 0 < p.meter_eff < 110]
if valid:
best = max(valid, key=lambda p: p.meter_eff)
print(f" ★ Best: {param_name}={best.param_value:.0f}"
f"EFF={best.meter_eff:.2f}%")
# Summary
print("\n" + "=" * 80)
print("DEADTIME OPTIMIZATION SUMMARY")
print(f"{'Bracket':<15} {'Best DT':>8} {'Efficiency':>12} {'Temp':>8}")
print("-" * 45)
for param_name, results in all_results.items():
valid = [p for p in results if 0 < p.meter_eff < 110]
if valid:
best = max(valid, key=lambda p: p.meter_eff)
print(f"{param_name:<15} {best.param_value:>8.0f} "
f"{best.meter_eff:>11.2f}% {best.stm_etemp:>7.0f}°C")
else:
print(f"{param_name:<15} {'N/A':>8} {'N/A':>12} {'N/A':>8}")
print("=" * 80)
return all_results
def apply_best_deadtimes(self, results: dict[str, list[TunePoint]]):
"""Apply the best deadtime from each bracket to the STM32."""
print("\nApplying optimal deadtimes:")
for param_name, points in results.items():
valid = [p for p in points if 0 < p.meter_eff < 110]
if valid:
best = max(valid, key=lambda p: p.meter_eff)
val = int(best.param_value)
ack = self.link.write_param(param_name, val)
status = "OK" if ack else "NO ACK"
print(f" {param_name} = {val} ({status})")
# ── Multi-point sweep ────────────────────────────────────────────
def sweep_param_multi(
self,
param_name: str,
start: float,
stop: float,
step: float,
voltages: list[float],
current_limit: float,
load_mode: str = "CP",
load_values: list[float] | None = None,
settle_time: float | None = None,
) -> list[TunePoint]:
"""Sweep a parameter across multiple voltage/load combinations.
Produces a comprehensive dataset showing how the parameter
affects efficiency across the full operating range.
"""
if load_values is None:
load_values = [200.0] # default: 200W
all_results: list[TunePoint] = []
for v in voltages:
for lv in load_values:
unit = "A" if load_mode == "CC" else "W"
print(f"\n── V={v:.0f}V, {load_mode}={lv:.0f}{unit} ──")
results = self.sweep_param(
param_name=param_name,
start=start, stop=stop, step=step,
voltage=v, current_limit=current_limit,
load_mode=load_mode, load_value=lv,
settle_time=settle_time,
)
all_results.extend(results)
return all_results
# ── Output ───────────────────────────────────────────────────────
@staticmethod
def print_results(results: list[TunePoint]):
"""Print a summary table of tuning results."""
if not results:
print("No results.")
return
valid = [p for p in results if 0 < p.meter_eff < 110]
if valid:
best = max(valid, key=lambda p: p.meter_eff)
print(f"\nBest: {best.param_name}={best.param_value:.1f}"
f"EFF={best.meter_eff:.2f}% "
f"(Pin={best.meter_pin:.1f}W Pout={best.meter_pout:.1f}W)")
@staticmethod
def write_csv(results: list[TunePoint], path: str):
"""Write tuning results to CSV."""
if not results:
return
with open(path, "w", newline="") as f:
w = csv.writer(f)
w.writerow([
"param_name", "param_value",
"voltage_set", "load_setpoint", "load_mode",
"meter_pin", "meter_pout", "meter_eff",
"stm_vin", "stm_vout", "stm_iin", "stm_iout",
"stm_eff", "stm_vfly", "stm_etemp",
])
for p in results:
w.writerow([
p.param_name, f"{p.param_value:.4f}",
f"{p.voltage_set:.4f}", f"{p.load_setpoint:.4f}", p.load_mode,
f"{p.meter_pin:.4f}", f"{p.meter_pout:.4f}", f"{p.meter_eff:.4f}",
f"{p.stm_vin:.4f}", f"{p.stm_vout:.4f}",
f"{p.stm_iin:.4f}", f"{p.stm_iout:.4f}",
f"{p.stm_eff:.4f}", f"{p.stm_vfly:.4f}", f"{p.stm_etemp:.4f}",
])
print(f"Results saved to {path}")
@staticmethod
def plot_sweep(results: list[TunePoint], show: bool = True):
"""Plot parameter sweep results."""
import numpy as np
import matplotlib.pyplot as plt
if not results:
return
param_name = results[0].param_name
vals = np.array([p.param_value for p in results])
eff_hioki = np.array([p.meter_eff for p in results])
eff_stm = np.array([p.stm_eff for p in results])
temp = np.array([p.stm_etemp for p in results])
# Filter valid
valid = (eff_hioki > 0) & (eff_hioki < 110)
# Group by operating point
ops = sorted(set((p.voltage_set, p.load_setpoint) for p in results))
fig, (ax1, ax2) = plt.subplots(2, 1, figsize=(12, 8), sharex=True)
cmap = plt.cm.viridis
for i, (v, l) in enumerate(ops):
color = cmap(i / max(len(ops) - 1, 1))
mask = np.array([
(p.voltage_set == v and p.load_setpoint == l and
0 < p.meter_eff < 110)
for p in results
])
if not np.any(mask):
continue
x = vals[mask]
order = np.argsort(x)
unit = results[0].load_mode
ax1.plot(x[order], eff_hioki[mask][order], "o-", color=color,
markersize=4, label=f"{v:.0f}V/{l:.0f}{unit}")
ax2.plot(x[order], temp[mask][order], "o-", color=color,
markersize=4, label=f"{v:.0f}V/{l:.0f}{unit}")
# Mark best
valid_pts = [p for p in results if 0 < p.meter_eff < 110]
if valid_pts:
best = max(valid_pts, key=lambda p: p.meter_eff)
ax1.axvline(best.param_value, color="red", linestyle="--", alpha=0.5)
ax1.plot(best.param_value, best.meter_eff, "*", color="red",
markersize=15, zorder=10,
label=f"Best: {best.param_value:.0f}{best.meter_eff:.2f}%")
ax1.set_ylabel("Efficiency (%)", fontsize=12)
ax1.set_title(f"Parameter Sweep: {param_name}", fontsize=14)
ax1.legend(fontsize=8)
ax1.grid(True, alpha=0.3)
ax2.set_xlabel(param_name, fontsize=12)
ax2.set_ylabel("Temperature (°C)", fontsize=12)
ax2.legend(fontsize=8)
ax2.grid(True, alpha=0.3)
fig.tight_layout()
if show:
plt.show()
return fig