STR-3221-R1 firmware v0.4.0 — stair standby lighting you can set, no reset

Firmware v0.4.0 is now the current release for the HomeMaster STR-3221-R1 stair LED and heating-zone module. The idle glow on the stairs is no longer tied to the first and last step numbers: you pick the channels, the level, and whether it runs always or only at night. Settings from v0.3.0 move across without a factory reset.

Standby lighting you can actually set

On v0.3.0 the night-light sat on whatever the step table called first and last. v0.4.0 gives those ends their own channel picks — Follow step table (the previous behaviour, and the default after an upgrade), any output O1…O32, or Off — and their own level. All-steps standby lights every channel in the step table; the chosen ends override that level, including zero, so a first step can stay dark while the rest of the table glows.

Standby when is either Always or Night window only (the same night window as holding register 438). Channels that leave the set — a shorter run, a moved map, first or last pointed elsewhere — are turned off. Previously they stayed lit after you changed the map.

WebConfig also has Fill from: write the step map in a run from a start channel (O10 and 12 steps become S1→O10 … S12→O21). The rest of the table is left alone.

Updating: settings stay

Flash the UF2. There is no factory reset. CFG_VERSION moves from 0x0005 to 0x0006; the migrator keeps every previous setting. The old Night-light level becomes All-steps standby, and first/last channels are set to Follow step table, so the stairs look the same the moment the module comes back.

The Modbus register map is unchanged. A v0.3.0 ESPHome package still talks to this firmware, so you do not have to rebuild the controller on the day you flash. Point packages: path: at v0.4.0 when you next compile, so later fixes arrive:

packages:
  str1:
    url: https://github.com/isystemsautomation/homemaster-dev
    ref: main
    files:
      - path: STR-3221-R1/Firmware/v0.4.0/default_str_3221_r1_plc/default_str_3221_r1_plc.yaml
        vars:
          str_prefix: "STR#1"
          str_id: str_1
          str_address: 3

Open only WebConfig v0.4.0. The map version is now 0x0040; the v0.3.0 page will refuse writes.

How to flash

1. Download the UF2 from the config hub or the repository.
2. On a module already running v0.4.0, Bootloader (USB) in the WebConfig Tools card writes unsaved settings and mounts the module as an RP2350 drive. On v0.3.0 that button is not there: hold buttons 1 and 2 and power-cycle, then release. The module mounts as a USB drive.
3. Copy the .uf2 onto that drive. The module flashes and reboots on its own.
4. Open WebConfig v0.4.0 and confirm firmware 0.4.0. Address, baud and the stair map you already had should still be there.

Unchanged

Register addresses, the ESPHome entity list and the on-module stair and heating engines are the same as v0.3.0. The sequence still runs with the controller off and the bus unplugged. Zone setpoints still come from the bus.

Wiring, the register map and the WebConfig reference are in the STR-3221-R1 README.