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Adom Fields

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Adom Fields: where the current and the heat go on your board.

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Closed PR #13 released in 0.10.6 on 5 Nov 2026 bug report

Grid stops short of the right board edge, so pads centred on the edge get no cell

Glenn Jones · ·closed by Colby Knox

We kept a list of tool issues as we worked on a project, the 772 power module (LM251772), a 4-layer board built with AI Flow on the Fusion lane, and set them aside so they wouldn't slow the build down. Now that the project is finished, we're filing them together. Some were seen on earlier versions; where we could, we checked that they still apply.

Versions: adom-fields 0.10.3 (not retested on 0.10.5).

What happens: on a 49.53 mm wide board (772 power module, LM251772), the grid was 247 columns x 0.2 mm = 49.4 mm. The castellation pads on the right edge are centred at x = 49.53, outside the last cell, so they had no copper in the grid. An explicit terminal on one of them failed with "a terminal has no copper under it".

Also, at on a terminal only matches a pad centre; it can't be used to move the injection point onto copper that is in the grid.

Expected: the grid covers the full board outline (round the column count up), so edge pads are modelled.

No design files attached; happy to describe more on request.

1 Reply

Colby Knox marked this in progress ·
Colby Knox mentioned this in pull request #13 ·
Colby Knox ·

Fixed in adom-fields 0.10.6. Upgrade with adom-wiki pkg install adom/adom-fields.

What changed

  • The grid now rounds up to whole cells, so it covers the full outline. Your 49.53 mm board gets 248 columns, 49.6 mm in all.
  • A pad centred on any board edge, or within 1 mm past it, now reaches the copper inside the grid. This also covers a case rounding up can't: a pad on the far edge of a board that is an exact number of cells, such as 50.00 mm, failed the same way.
  • The last column and row can reach slightly past the outline. Only the part on the board loses heat to the air, and the viewer stops the fields at the outline.
  • at on a terminal is unchanged: it still picks one physical pad by its centre. With edge pads in the grid, you shouldn't need it to move the injection point.

Numbers can shift a little. A board that isn't a whole number of cells gains a column or row. Peak temperature rise moved by under 1 % on the two real boards where that happened, so a value right on a threshold can cross it.

How it was tested

  • An explicit terminal on a right-edge pad at 49.53, 50.00 and 49.46 x 20.03 mm fails on 0.10.5 and solves on 0.10.6, also with --with all. A 49.53 mm Fusion .brd does too.
  • Boards that are already a whole number of cells keep the same grid and heat results: a 28 x 20 mm buck and a 50.4 x 26.4 mm Fusion board.
  • The viewer alignment was checked on a coarse-grid test board.

Not tested: your 772 board itself, since we don't have the file, and verify and report on the new grid.

Colby Knox closed this ·

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