HPCS6500-py/README.md

HPCS 6500 — Open-Source Driver

Python driver and CLI for the HPCS 6500 spectrophotometer / integrating sphere.

Communicates directly with the instrument over USB serial, replacing the vendor software for measurement automation and data extraction.

What This Does

• Measure: Luminous flux (lm), CCT (K), CRI (Ra, R1-R15), chromaticity (CIE xy, uv, u'v'), radiometric flux, spectrum 380-1050 nm
• Electrical: Voltage, current, power, power factor, frequency
• Harmonics: 50-harmonic voltage/current analysis, UThd, AThd, waveforms
• Power supply: Control the built-in AC (100-240V, 50/60Hz) and DC (1-60V, 0-5A) power supply
• Export: CSV output for data logging
• TM-30: ANSI/IES TM-30-18 Rf, Rg, and hue-bin data computed from the measured spectrum (via colour-science)
• Lamp bundles: one-command export of spectrum + TM-30 + metrics for the buildfor.life lamp comparison

Quick Start

# Install
uv sync

# Single measurement (auto-detects device, turns PSU on/off)
uv run hpcs6500.py

# Continuous measurements
uv run hpcs6500.py --continuous

# Quick test (lumen + CCT only)
uv run hpcs6500.py --quick
uv run hpcs6500.py --quick --continuous

# Show full spectrum + harmonics
uv run hpcs6500.py --spectrum --harmonics

# Save to CSV
uv run hpcs6500.py --continuous --csv output.csv

Power Supply Control

# Read current PSU settings
uv run hpcs6500.py --psu-status

# Set AC mode, 230V 50Hz
uv run hpcs6500.py --mode ac --voltage 230 --frequency 50

# Set DC mode, 12V with 1A current limit
uv run hpcs6500.py --mode dc --voltage 12 --current 1.0

# Manual PSU on/off
uv run hpcs6500.py --psu-on
uv run hpcs6500.py --psu-off

# Set integration time (ms)
uv run hpcs6500.py --integration 500

Lamp Comparison Export

Produces the per-lamp data bundle consumed by the buildfor.life comparison pages: spd.csv (full 380-1050 nm spectrum), tm30.csv (TM-30-18 hue-bin data for the color vector graphic), and metrics.json (photometric, colorimetric, CRI R1-R15, TM-30 Rf/Rg, electrical).

# Single reading from the device
uv run lamp_export.py --name philips-a60-8w --manufacturer Philips --model "A60 8W 927"

# Average several readings
uv run lamp_export.py --name philips-a60-8w --readings 5

# Power the lamp from the built-in supply: 230 V / 50 Hz, 60 s warm-up,
# PSU switches on before the readings and off afterwards
uv run lamp_export.py --name philips-a60-8w --voltage 230 --frequency 50 --settle 60

# From an existing pcap capture
uv run lamp_export.py --name some-lamp --parse captures/run.pcap

Output lands in lamps/<name>/. TM-30 is computed from the measured spectrum with colour-science; the spectrum is relative, which TM-30 is invariant to. Sanity check of the implementation: uv run tm30.py reproduces the published values for the CIE FL2 illuminant (Rf 70, Rg 86).

Offline Parsing

Parse previously captured USB traffic (pcap files from USBPcap):

uv run hpcs6500.py --parse captures/some_capture.pcap
uv run hpcs6500.py --parse captures/some_capture.pcap --quick

Files

File	Description
hpcs6500.py	Driver class (HPCS6500) and CLI
lamp_export.py	Lamp comparison bundle export (spd/tm30/metrics)
tm30.py	ANSI/IES TM-30-18 computation from a spectrum
usb_capture.py	USB traffic capture tool (requires USBPcap)
PROTOCOL.md	Complete protocol reference (byte-level)
pyproject.toml	Project metadata and dependencies

Hardware

• Device: HPCS 6500 spectrophotometer / integrating sphere
• USB: STM32 Virtual COM Port (VID 0483, PID 5741)
• Protocol: Custom binary over serial, documented in PROTOCOL.md

Dependencies

• Python 3.11+
• pyserial (serial communication)
• colour-science (TM-30 computation)
• USBPcap (only for usb_capture.py, not needed for normal operation)

Protocol

The binary protocol is fully documented in PROTOCOL.md, including all command bytes, data block layouts, field offsets, and the complete measurement sequence. This was reverse-engineered from USB packet captures of the vendor software.