Legend
solder link = short wire soldered flat on the back between two holes (insulated where links cross)
dashed link = confirm-on-board
copper pad = a used hole (solder here)
grid coord = B<board>:<col-letter><row-number>
Grid coordinates. Each 50×70 perfboard is 18 columns
(A–R) × 26 rows (1–26) at 0.1″ pitch. The
three joined boards are B1 · B2 · B3 (seams at the scribed lines), so
every hole has a unique address like B1:C4 — board B1, column C, row 4.
Rulers print the letters along the top edge and the numbers down the left edge
of each board, like a chessboard. The same physical hole keeps the same
coordinate when you flip to the solder side — the back rulers are placed so
C4 stays C4 (this flip turns the board about its long edge, preserving
left–right, so columns are not renumbered on the back). Toggle with
Grid coords.
A perfboard has no copper traces. Every connection here is a short wire
link soldered on the BACK between two holes — exactly how you wire a perfboard.
Each link lays flat against the back surface, follows the hole grid, is
soldered ONLY at its two endpoint pads, and is coloured by net. It lays over any
interior holes without joining them. Where two links cross, use insulated wire
so the crossing does not short. Modules sit on the FRONT. Hit Flip · solder
side to turn the assembly over and see where the iron goes — exactly how you
flip the real board.
Pin labels cycles Off → Wired → All. Every pin is also named on hover.
Grid coords cycles Off → Wired → All for the per-pin coordinate chips
and the edge rulers; the coordinate also shows on hover/click and in every
solder instruction.
Power & ground run on two reserved rail rows; land every VCC/GND on the
rail, not on a single MCU pin. The MiCS-6814 supply (VCC/GND/Vh) is
unconfirmed (likely ~5V) — confirm pin names and heater voltage on your board.
Footprints are photo-derived for the 5 photographed boards (ESP32-S3,
BME688, TCA9548A mux, SGP40, SHT40): pin counts, header layout and the
ESP32 row gap (9 holes); left header 22 pins, right 21 (43 total) are read off the operator's
hardware photos. Each pin's hole is computed from its header position.
The arrangement is a layout choice. Which module sits where (and each
module's origin hole) is a committed design decision, not photo-measured —
only the ESP32 is shown placed in a photo. ADS1115, MiCS-6814 and the
microSD breakout were not photographed; their footprints are
estimates and stay confirm-on-board. Nets are confirmed only where
tagged verified; confirm nets still need checking.