Motor pid

PID Motor Control Loop — Lab 10L on one board

The motor-position feedback loop of Learning the Art of Electronics (Hayes & Horowitz), Lab 10L, as a 170 x 120 mm printed circuit board whose silkscreen is the schematic. A motorized slide fader (the lab's Bourns PSM01-082A-103B2, or any 100 mm fader with a 10k track and a 6–11 V motor) wires to two screw terminals; the board holds the fader's wiper at the position a knob or a signal generator asks for, with proportional, derivative and integral terms the student switches in and turns up one at a time, exactly as the lab does.

Every node the lab asks you to look at has a probe loop (17 probe loops, four of them ground). Every stage sits in a dashed box named as the book names it. The three gain trimmers are labelled P GAIN, D GAIN and I GAIN, each with an arc over it saying what clockwise does (more resistance: more P, more D, less I); the switches say in words what each position does.

What is on it

The design departs from the book where the parts or the pedagogy asked for it; each departure is in docs/DESIGN_NOTES.md.

Using it

docs/HANDBOOK.md: bring-up without the fader, wiring the fader and checking its polarity, the expected voltage at every loop, and the lab's exercises in the lab's order (P alone and the residual error, raising the gain until it oscillates, adding D, then I, then driving it with a square wave). The back of the board carries the short version.

Ordering it

docs/MANUFACTURING.md is generated by the build: the files to upload, JLCPCB's order form field by field, the cost, and what to look at in their placement preview. There are about $12.21 in parts per board. Order 2 oz outer copper, not the default 1 oz: the copper round the two power transistors is their heatsink.

Building it

./make.py

runs, from scripts/parts.py outward: the footprints and 3D stand-ins, the ngspice simulation of the loop (from the exported netlist, with a model of the fader), the schematic (scripts/gen_sch.py) and its ERC, 258 circuit assertions on the netlist (scripts/check_circuit.py), the board (scripts/layout.py placed and wired by scripts/gen_pcb.py, where every drawn wire is laid as copper) and its DRC with schematic parity, the fab package and its checks (scripts/check_outputs.py), and the documents, whose every quoted number is checked against the build. KiCad 10 is needed; the build finds its AppImage.

Files

• hardware/ — the KiCad project (generated; do not edit by hand)
• scripts/ — the generators and checkers
• sim/ — the simulation and its results
• out/motorpid/ — gerbers, BOM, CPL, prints, assembly notes
• docs/ — handbook, design notes, manufacturing, images
• CLAUDE_CODE_CHAT.md — how this was designed, prompt by prompt

Licence

Hardware under CERN-OHL-P v2 (LICENSE-HARDWARE.txt), scripts under MIT (LICENSE). The circuit is Hayes & Horowitz's; the board is Jason Gallicchio and Claude, 2026.