Light Meter (LM324 bar graph)

1. Prepare

Verify component pinouts against each manufacturer’s datasheet before wiring. Label cut wires with their wire numbers; the same numbers follow them through every stage. Wire colors are written out for black-and-white printing. Custom colors can be named in the wire library.

Progress is saved on this browser for this board revision. Changes to the board or measurements start a new checklist. Printed diagrams are references, not life-size templates.

21 wires to prepare; 787mm total wire, including end allowances.

Parts List

8 unique parts

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2. Cut wires

21 wires · +5mm per end for lead-through

Total wire: 787mm (31.0in)

3. Bend wires

Use the straight-line ruler to mark bend points on the wire before bending. Use the bent shape as a visual reference while bending.

Wire 1 — OUT1 — F23 → F19 — 20mm — Red

Cut 20mm.

Wire 2 — OUT3 — L23 → L19 — 20mm — Yellow

Cut 20mm.

Wire 3 — T1 — E12 → G19 — 38mm — White

Cut 38mm. Bend 90° down at 8mm. Bend 90° right at 25mm.

Wire 4 — T3 — J13 → K19 — 38mm — Green

Cut 38mm. Bend 90° down at 13mm. Bend 90° left at 28mm.

Wire 5 — OUT2 — H22 → E16 — 33mm — Blue

Cut 33mm. Bend 90° up at 13mm.

Wire 6 — OUT4 — M23 → M16 — 28mm — Black

Cut 28mm.

Wire 7 — T2 — H7 → G15 — 33mm — Red

Cut 33mm. Bend 90° down at 8mm.

Wire 8 — T4 — L7 → K15 — 33mm — Yellow

Cut 33mm. Bend 90° down at 8mm.

Wire 9 — SENSE — O4 → J15 — 51mm — White

Cut 51mm. Bend 90° left at 33mm.

Wire 10 — SENSE — Q4 → H15 — 61mm — Green

Cut 61mm. Bend 90° left at 33mm.

Wire 11 — SENSE — P3 → J19 — 66mm — Blue

Cut 66mm. Bend 90° down at 8mm. Bend 90° left at 48mm.

Wire 12 — SENSE — P5 → H19 — 66mm — Black

Cut 66mm. Bend 90° down at 8mm. Bend 90° left at 43mm.

Wire 13 — VCC — N13 → I15 — 28mm — Red

Cut 28mm. Bend 90° down at 18mm.

Wire 14 — VCC — O12 → F13 — 35mm — Yellow

Cut 35mm. Bend 90° left at 8mm.

Wire 15 — VCC — N11 → K4 — 35mm — White

Cut 35mm. Bend 90° up at 13mm.

Wire 16 — VCC — L3 → C3 — 33mm — Green

Cut 33mm.

Wire 17 — GND — E8 → E4 — 20mm — Blue

Cut 20mm.

Wire 18 — GND — G8 → F14 — 28mm — Black

Cut 28mm. Bend 90° left at 20mm.

Wire 19 — GND — E15 → I19 — 30mm — Red

Cut 30mm. Bend 90° right at 15mm.

Wire 20 — GND — F7 → Q8 — 40mm — Yellow

Cut 40mm. Bend 90° down at 33mm.

Wire 21 — GND — D14 → D30 — 51mm — White

Cut 51mm.

4. Place wires

Component side. Select a wire to emphasize its route in its own color and highlight its endpoints. Wires follow number order, matching the bend guide and solder checklist.

5. Solder connections

Bottom view: horizontally mirrored. Coordinate names still identify the same physical holes. Highlights mark wire endpoints; wire routes belong on the component side. Check each connection and the listed solder bridges.

Board is horizontally mirrored. Column A is on the right.