jst_ph_4 footprint generates only 2 pads instead of 4

[dwiel]

Summary

The jst_ph_4 footprint (JST PH connector with 4 pins) only generates 2 pads instead of 4.

Root Cause

In src/fn/jst.ts:

1. Line 169 hardcodes numPins = 2 for the PH variant:

   let numPins = variant === "sh" ? 4 : 2

2. The SH variant parses pin count from the string (e.g., jst_sh6 → 6 pins), but PH does not.

3. The generatePads() function for PH (lines 84-105) only creates 2 pads at fixed positions, ignoring the numPins parameter entirely.

Reproduction

<chip name="J1" footprint="jst_ph_4" />

Export to KiCad PCB - only 2 pads are generated.

Expected

4 through-hole pads for jst_ph_4, similar to how jst_sh6 generates 6 pads.

Suggested Fix

1. Parse pin count from the footprint string for PH variant (e.g., jst_ph_4 → 4 pins)
2. Update generatePads() to dynamically create numPins pads for the PH variant

Impact

JST PH connectors with more than 2 pins cannot be used via the built-in footprint string.

[seveibar]

Do you have a reference from e.g. kicad for what you're looking for? jst_ph_4 is not really written how i think footprinter would parse it- it should be jst4_ph i think, but it's possible someone made an error in implementation.

[seveibar]

e.g. are you looking for something like this? https://tscircuit.github.io/kicad-viewer/#Connector_JST.pretty/JST_GH_SM04B-GHS-TB_1x04-1MP_P1.25mm_Horizontal.kicad_mod

[dwiel]

Not an EE by trade, so can't really suggest a convention. Just noticed that the PH variant is hardcoded to 2 pins in src/fn/jst.ts (line 169) while SH parses the pin count from the string.

The link you shared is JST GH (1.25mm pitch, surface mount) - I'm specifically interested in the PH series (2.0mm pitch, through-hole).

KiCad reference for 4-pin PH: https://tscircuit.github.io/kicad-viewer/#Connector_JST.pretty/JST_PH_B4B-PH-K_1x04_P2.00mm_Vertical.kicad_mod

Whatever syntax makes sense to you works for me.

[dwiel]

I'd also be happy to provide a PR, I just wasn't sure what was most helpful on that front these days.

[aifunmobi]

Would this be eligible for a bounty? I'd like to take this on — the fix is straightforward:

1. Parse pin count from the PH footprint string (e.g. jst_ph4 → 4 pins), matching how SH already works
2. Make generatePads() for PH use the parsed numPins instead of hardcoded positions
3. Add test coverage for PH variants with different pin counts

Happy to follow whichever naming convention you prefer (jst_ph4 vs jst4_ph).

[Pitrat-wav]

I've implemented the fix for Issue #495. The jst function now correctly parses the pin count for PH variants when defined via string (e.g., jst_ph_4). PR: #507

[quantbitrealmSimon]

I have submitted a fix for this issue in PR #513.

The fix adds support for the jst_ph_X footprint string format by updating the regex pattern to handle pin counts specified after the variant (ph/sh) component.

/claim