SSR5A

BleRiot SSR5A

SSR5A is a mains-powered five-channel BleRiot switch intended primarily for zone thermo-electric actuators in hydronic heating systems. Each independently controlled output switches mains line through a zero-cross optotriac and triac.

The board combines a PY32F030 microcontroller, PAN2110 radio, five output channels, a WS2812B status LED, and an isolated 3.3 V mains power supply. The outputs are on/off switches; they are not phase-angle dimmers.

Connections

Connector numbering follows the KiCad schematic.

Each channel uses a MOC306x zero-cross optotriac and BTA08S-600CW triac. Its on-board indicator LED follows the output directly.

BleRiot Registers

An enabled channel is exposed as a writable boolean register:

Each channel has inventory-as-code configuration in fw/cmd/dev/main.go:

• Disabled omits the register and holds the physical output off.
• Inverted reverses the logical-to-physical output mapping.
• Default selects the logical value applied after power-on and RF link loss.

Disabled takes precedence over inversion and the default. At startup, firmware first biases every active-low triac control inactive, then applies the configured defaults.

The node considers the BleRiot link offline after five seconds without a valid packet. On the online-to-offline transition, it immediately restores every channel to its configured logical Default and reapplies the corresponding physical output level. This fail-safe also honors Inverted; for example, an inverted channel with Default: false is physically energized while offline. Choose defaults for the required safe state of the installation.

Stavová LED na PA6 zobrazuje spojení a logický stav kanálů. Od firmware fw/v1.1.4 používá stejné oranžové barvy jako CPG:

Aktivita se řídí logickou hodnotou registru bez ohledu na inverzi výstupu; zakázané kanály zelenou indikaci neaktivují. Offline indikace má přednost. Změna barev je ověřená testy a sestavením, nikoliv na fyzické LED.

The RF-loss behavior has been verified on hardware: channel 1 was commanded on, the hub was stopped, and its active-low MCU output returned inactive after the five-second link timeout. After reconnecting, all five registers reported their configured false defaults.

Hardware And Firmware

The importable ssr5a firmware exports Run and targets the py32f030x8 profile. Its device type owns the scheduler-none build policy and 100 kHz attach-mode pyOCD settings. The local inventory bridges the radio node to a Registry server. The SWD connector carries SWDIO, ground, and SWCLK but no reset or target-voltage connection.

Repository Layout

• board/ contains the KiCad schematic, PCB, BOM, and fabrication outputs.
• fw/ contains the importable TinyGo firmware, tests, and build profile.
• fw/spec/ contains configuration, the config-dependent register table, chip, and firmware manifest.
• fw/cmd/dev/ contains the local inventory and BleRiot CLI.
• fw-orig/ contains the original MicroPython firmware for reference.
• sub/hw-kicad/ is the shared KiCad library submodule.

Initialize the shared hardware library after cloning:

git submodule update --init --recursive

Build And Test

The firmware requires Go, TinyGo with Puya target support, GNU Arm Embedded binutils, and pyOCD with the Puya CMSIS pack.

go -C fw test ./...
go -C fw run ./cmd/dev node gen --name ssr
go -C fw run ./cmd/dev node build --name ssr --disassembly
go -C fw run ./cmd/dev node build --name ssr --flash --rtt

With a Registry server running, start the local hub:

go -C fw run ./cmd/dev hub --registry http://localhost:8080 --diagnostics rf

Safety

This design connects directly to hazardous mains voltage. Assembly, installation, testing, and enclosure work must be performed by suitably qualified people using applicable electrical codes and safe isolation practices. Independently verify protection, creepage and clearance, protective earth continuity, enclosure construction, triac thermal limits, and actuator ratings before deployment.

Do not wire mains or an actuator from this README alone. Verify the assembled board against the schematic, PCB, and actuator manufacturer's documentation.