CPG

BleRiot Circulation Pump Group Controller

CPG is a mains-powered BleRiot node for controlling a circulation pump and a motorized 3-way or 4-way valve in floor-heating and radiator-heating circuits. It provides one switched output for the pump and two interlocked directional outputs for a reversible valve actuator.

The board is intended for supervisory heating control. Its triac channels are on/off outputs; they are not phase-angle dimmers.

Functions

• Circulation pump on/off control.
• Clockwise and counter-clockwise valve actuation.
• Firmware interlock preventing both valve directions from being energized at the same time.
• 100 ms break-before-make delay when changing valve direction; the latest command received during the delay wins.
• PAN2110 sub-GHz radio running the BleRiot register protocol.
• WS2812 status LED for local state indication.
• Explicit watchdog lease with a configurable safe valve position.
• 30-second RF link-loss fail-safe.
• Onboard PY32F030 microcontroller and mains-to-3.3 V power module.

This arrangement supports common motorized mixing and diverting valves whose actuator has a neutral connection and separate CW and CCW live inputs. Confirm the actuator wiring and required reversal delay against its documentation.

Connections

Connector numbering follows the KiCad schematic and PCB footprints.

The three switched outputs use BTA08S-600CW triacs driven through MOC306x optotriacs. The pump channel is independent. Valve CW and CCW share a firmware interlock and must also be treated as mutually exclusive by any external controller.

BleRiot Registers

A value of 0 is off and 1 is on. During valve reversal both valve registers report off until the dead time expires and the pending direction is energized. Null and unknown writes are ignored, and other boolean values are normalized to 1. The former test-only LED register is retired.

The watchdog starts expired. Positive writes arm it for up to 60 seconds, and reads return the remaining whole seconds rounded up. Zero, negative, and NULL writes expire it immediately. While expired, pump and valve writes are ignored. Re-arming does not restore prior commands; the controller must send fresh output writes.

While the BleRiot link is online and the watchdog is armed, the status LED is automatic:

Valve state has priority over pump state. During valve dead time, the LED shows the pump indication when the pump is on and the idle indication otherwise. An expired watchdog blinks blue (0x0000ff): 200 ms on and 800 ms off. An RF offline link blinks orange (0xff3000) with the same timing and takes priority over the watchdog indication.

When the watchdog expires, firmware switches the pump off and commands the valve to its configured safe end. Valve reversal still uses the configured break-before-make delay. WatchdogSafePositionCCW in fw/cmd/dev/main.go selects the safe end: false selects CW and true selects CCW. The current baked configuration selects CW. The safe direction remains energized for actuators with internal end-limit switching.

Independently, 30 seconds without a valid RF packet marks the link offline and applies the same safe state once. Startup remains all-off until the explicit watchdog is armed; output writes are ignored before then.

Firmware And Pin Mapping

The firmware targets a PY32F030F1 MCU and controls a PAN2110 radio over three-wire SPI.

At startup, firmware preloads PB4-PB6 high before changing them to outputs so the active-low optotriac inputs remain off. All three switched outputs start off. The status LED uses the offline heartbeat until a valid packet is received.

There is no mains zero-cross input. The MOC306x optotriacs shown in the schematic are zero-cross devices, so these channels provide on/off switching only.

Repository Layout

• board/ contains the KiCad schematic, PCB, BOM, and fabrication outputs.
• fw/ contains the importable cpg TinyGo firmware and board-owned build profile.
• fw/spec/ contains the configuration, register contract, chip, and firmware manifest.
• fw/cmd/dev/ contains the local inventory and BleRiot CLI.
• burgrp/tinygo-drivers/ws2812 contains the reusable 24 MHz PY32 WS2812 driver.
• sub/hw-kicad/ is the shared KiCad library submodule.

Initialize the hardware library after cloning:

git submodule update --init --recursive

Build And Test

The firmware requires Go, TinyGo with the PY32 target support used by this project, GNU Arm Embedded binutils, and pyOCD with the Puya device pack.

cd fw
go test ./...
go run ./cmd/dev node gen --name cpg
go run ./cmd/dev node build --name cpg --disassembly

BleRiot generates a private entry point under .bleriot/firmware/cpg and calls cpg.Run with the configured identity and spec.Config. The firmware profile selects py32f030x8, scheduler-none, leaking GC, RTT serial, and a 100 kHz pyOCD connection.

The first board was programmed through a WCH-Link at 100 kHz using an under-reset connection. With the board connected:

cd fw
go run ./cmd/dev node install-pack --name cpg
go run ./cmd/dev node build --name cpg --flash --rtt

Confirm the fitted MCU density before relying on the py32f030x8 target. Check the physical board before using X1: older board revisions route the SWD header labels to the wrong MCU pins and do not expose target voltage or reset.

Hardware Status

The current firmware has been built, flashed, and exercised on the board:

• PAN2110 startup was confirmed over RTT on BleRiot channel 37 with spread factor S8.
• Safe startup was confirmed with pump, CW, and CCW outputs all off.
• The valve interlock and latest-command state machine are covered by host tests.
• The WS2812 waveform and all RGB channels were validated at 3.3 V.

End-to-end testing with the intended pump, valve actuator, heating controller, and RF hub is still required for each installation.

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.

Before deployment, independently verify at least:

• Input fusing and upstream over-current protection.
• PCB creepage and clearance for the applicable mains category.
• Protective-earth continuity and enclosure construction.
• Triac current, thermal, and inductive-load commutation margins.
• The exact MOC306x trigger-current grade and the fitted 270 ohm input resistor.
• WS2812 operation at 3.3 V, below the linked part's specified supply range.
• Pump and valve actuator voltage, current, wiring, and duty-cycle limits.
• Required valve reversal delay and behavior after RF or controller loss.

After watchdog or RF timeout expiry, the pump switches off and the configured valve direction remains energized. Confirm that the actuator has suitable internal end-limit switching, and define maximum pump and valve run times for the installation.

Do not connect a pump, valve, or mains supply based only on the connector table; verify the assembled board against the schematic, PCB, and the equipment manufacturer's wiring documentation.