metronome/hardware/eda
Me Here 075c1786af PM_K-1 hardware: verify THAT1240 against datasheet; fix pinout + part numbers
Verified the receiver from THAT doc 600035 rev05 instead of guessing:
- THAT1240 = 0 dB (unity) -- correct as specced; 1243=-3dB, 1246=-6dB would be wrong.
- SO-8 pinout 1=Ref 2=In- 3=In+ 4=Vee 5=Sense 6=Vout 7=Vcc 8=NC. My initial
  SKiDL pins were mostly wrong; corrected. Netlist now matches the datasheet.
- KiCad Device:D is pin1=K/pin2=A; my clamp diodes were reversed -- fixed so they
  actually clamp (D high->cathode to +15, D low->anode to -15).
- BOM part numbers had a bogus "W16" suffix; corrected to S08-U (SO-8). Noted
  INA134/SSM2141 as pin-compatible 2nd sources for long-term availability.

ERC 0 errors, netlist 0 errors.

Co-Authored-By: Claude Opus 4.8 (1M context) <noreply@anthropic.com>
2026-05-30 19:48:41 -05:00
..
circuits PM_K-1 hardware: verify THAT1240 against datasheet; fix pinout + part numbers 2026-05-30 19:48:41 -05:00
sim PM_K-1 hardware: Stage 1 audio (input receiver) sims + container libs 2026-05-30 19:27:25 -05:00
Containerfile PM_K-1 hardware: Stage 1 input receiver as SKiDL (code-defined schematic) 2026-05-30 19:43:07 -05:00
README.md PM_K-1 hardware: reproducible EDA container (KiCad 9 + ngspice) 2026-05-30 19:17:54 -05:00
run.sh PM_K-1 hardware: reproducible EDA container (KiCad 9 + ngspice) 2026-05-30 19:17:54 -05:00

PM_K-1 EDA environment

A reproducible container with the tools to design, check, and simulate the core board — so the work doesn't depend on whatever happens to be installed on a given machine, now or in 50 years.

What's inside

  • KiCad 9 — schematic capture + PCB layout, and a CLI (kicad-cli) that can run ERC (Electrical Rules Check) and DRC, and export netlists/PDF/Gerbers.
  • ngspice — SPICE simulator for validating the analog audio circuits before we commit copper (op-amp stages, filters, input loading, etc.).
  • python3 — scripting, BOM munging, optional code-defined-schematic helpers.

Why a container?

The system KiCad here is 7.0, whose CLI can't run ERC (that arrived in KiCad 8). Rather than fight the host, we pin a known toolchain. Anyone — including future-you — rebuilds the exact environment with one command.

Use it

cd hardware/eda
./run.sh                                   # interactive shell, lands in hardware/kicad/
./run.sh kicad-cli version                 # confirm KiCad 9
./run.sh kicad-cli sch erc pm_k1_core.kicad_sch   # run ERC on the schematic
./run.sh ngspice -b ../eda/sim/input_loading.cir  # run a simulation (cwd is kicad/)

run.sh builds the image on first use, then mounts the whole repo at /work (so KiCad sees hardware/). Use RUNTIME=docker ./run.sh … to use Docker instead of Podman.

Layout

eda/
  Containerfile      # the pinned toolchain (KiCad 9 + ngspice + python)
  run.sh             # build-if-needed + run with the repo mounted
  sim/               # ngspice decks (SPICE simulations of the analog circuits)