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Hardware field notes

github-actions[bot] edited this page May 19, 2026 · 1 revision

Hardware field notes

Community-reported combinations of spa panel, board, and PlatformIO environment. This is not a compatibility guarantee — add what you tested.

For planned boards (no checked-in env yet), proposed bring-up steps and checklists live on Hardware targets.

To add a row: edit this page or open an Issue with the same fields.


Reading BPxxx, CLxxx, and “Agency Model” strings

These labels come from different layers of the same system, so it is normal to see more than one “model” on a sticker:

What you see Typical meaning
BP501 Balboa control pack family — Balboa Water Group documents BP501 (North America) and BP601 (Europe) as the “BP 501/601” control system line. See BP 501/601 — Balboa Water Group.
CL501X1 Often printed as the heater / spa-pack configuration segment that dealers bundle with BP501 (parts listings frequently say “BP501 … with Heater CL501X1”). It is not a competing protocol name — tub-side RS485 for these packs is still Balboa’s usual 115200 8N1 framing (see protocol.md — RS-485).
Agency Model BP501-CL501X1-AS Full agency / certification-style designation: pack family (BP501) + configuration segment (CL501X1) + suffix (AS, often an agency or regional variant). Prefer this full string in the table below for searchability; keep CL501X1 alongside it if the short code is what you remember.

The firmware’s information response can expose a system model ASCII field (e.g. variants like MQBP501 in examples from protocol.md — Information Response); that is the runtime name from the controller, not the same typography as the enclosure label.


Parts that worked (community)

Not a compatibility guarantee — verify pinout, wire gauge, and crimp tooling for your tub. You still need the correct terminals crimped into the housing (Molex publishes mate part numbers separately).

Part Supplier Use
Molex 0451320403 (4-circuit plug housing) DigiKey WM16117-ND On a Balboa BP501 tub, maintainer report: mates cleanly with the factory-installed header on the spa board so you can run a short harness to the M5 Atomic RS485 base VH‑3.96 / bus terminals without cutting the factory harness. Confirm 12 V / GND / A / B (or your board’s pin order) against ccutrer physical layer and your label before energizing.

Add other SKUs here when you have a tested combination.


Reported setups

Tub / panel (report) Board / stack PlatformIO env RS485 notes Outcome
Balboa BP501; agency BP501-CL501X1-AS; also stamped CL501X1 (heater/pack segment — see above) M5 Atom Lite + Atomic RS485 Base (stacked tub-side gateway) M5AtomLite-tub TX485_Rx 22, TX485_Tx 19; AUTO_TX true; A/B per base labeling (swap if no frames). Harness: Molex 0451320403 (DigiKey WM16117-ND) plugged onto the factory header on the spa board → short leads to Atomic base (see Parts that worked). physical layer; BWG BP 501 Works — maintainer tub-side stack (README, config-example.h)
(example) Balboa BP7xxx M5 Atom Lite + Atomic RS485 Base M5AtomLite-tub A/B as labeled on base; AUTO_TX true Example row

Suggested fields for new reports

Copy this template into the table or an Issue:

Tub / panel model:
Board (e.g. M5 Atom + Atomic RS485, generic ESP32):
PlatformIO env:
TX485_Rx / TX485_Tx:
AUTO_TX (true/false):
A/B wiring notes:
Firmware version (/api/version):
What works:
What does not:

Official hardware docs in the main repo

Bus tapping and wire colors: ccutrer BWA wiki — physical layer.


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