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Nie, dziękuję Przekieruj mnie tamsetup openBK for tuya pilot wire
• Flash OpenBeken (OpenBK) onto the Tuya pilot-wire module, then assign the two GPIOs that drive the positive and negative half-wave outputs to the dedicated “Diode _R_B” driver in OpenBK.
• After saving the template the pilot-wire channel (Ch 1 by default) accepts the following values:
0 = Comfort, 1 = Eco, 2 = Frost-protection, 3 = Off.
• Verify the wave-shapes with a multimeter/oscilloscope, then expose the channel through MQTT or HTTP for Home-Assistant or any other automation platform.
1 Pilot-wire (fil-pilote) principle
• A single control conductor referenced to Neutral conveys four main heater orders by inserting specific half-wave patterns into the 50 Hz mains:
– No signal (open) → Comfort
– Full sine (both half-waves) → Eco (-3 … -4 °C)
– Only negative half-wave → Frost-protection (≈ 7 °C)
– Only positive half-wave → Off
• Most Tuya pilot-wire relays implement two opto-triac channels (sometimes relays + diodes) that can be driven independently to create the three composite wave-forms.
2 Hardware used by Tuya
• Main RF/MCU module: BK7231T, BK7231N, WB3S, CB3S – fully supported by OpenBK ≥ 1.17.0.
• Pilot-wire power stage: two opto-triacs (e.g. MOC3063) feeding a power triac or two SSRs plus steering diodes.
• Exposed test pads: TX/RX, 3 V3, GND and CEN (reset/boot-strap).
3 Firmware driver inside OpenBK
• “Diode_R_B” (aliases: DIODES_R_B, PilotWire4Mode) → consumes two GPIOs:
• GPIO_A → Role Diode_R_B_A (positive half-wave)
• GPIO_B → Role Diode_R_B_B (negative half-wave)
• OpenBK internally creates one integer Channel (default Ch 1) whose value encodes the 4 modes shown above.
• Swapping the two roles inverts “Off” and “Frost”; this is the first thing to try when the modes look reversed.
4 Signal timing
OpenBK automatically synchronises to the 50 Hz zero crossings; you do not need external zero-cross hardware for typical Tuya boards because the opto-triacs are zero-cross versions.
• Tuya-cloudcutter (v0.8+) now supports BK7231x pilot-wire devices OTA if factory firmware ≤ 1.1.9; this avoids soldering in ~70 % of cases.
• OpenBK added Web-installer (USB-Web-serial) for Chrome/Edge, easing serial flashing on Linux/Mac.
• A community template database (GitHub → obk-templates.json) auto-detects many pilot-wire boards and pre-assigns the Diode_R_B pins.
• MQTT-AutoDiscovery for Home-Assistant is built-in since OpenBK 1.16 – the heater shows up as climate.* without YAML.
• Matter/Thread support is on the roadmap but experimental.
Pilot-wire timing matrix:
| Value | Positive HW | Negative HW | Resulting mode |
|---|---|---|---|
| 0 | 0 | 0 | Comfort |
| 1 | 1 | 1 | Eco (both) |
| 2 | 0 | 1 | Frost (– half) |
| 3 | 1 | 0 | Off (+ half) |
(1 = channel energised, 0 = idle)
Example console commands:
setChannel 1 0 // comfort
setChannel 1 1 // eco
setChannel 1 2 // frost-protection
setChannel 1 3 // offHome-Assistant manual YAML (if you do not use Auto-Discovery):
mqtt:
climate:
- unique_id: heater_lr
name: "Living-Room Pilot-Wire"
modes: ["heat","off"]
preset_modes: ["comfort","eco","away","off"]
mode_state_topic: "stat/pilotwire/Ch1"
mode_command_topic: "cmnd/pilotwire/Ch1"
mode_command_template: >
{% if value == "heat" %}0{% else %}3{% endif %}
preset_mode_state_topic: "stat/pilotwire/Ch1"
preset_mode_command_topic: "cmnd/pilotwire/Ch1"
preset_mode_command_template: >
{% set map={'comfort':0,'eco':1,'away':2,'off':3} %}
{{ map[value] }}
preset_mode_value_template: >
{% set map={'0':'comfort','1':'eco','2':'away','3':'off'} %}
{{ map[value] }}• Mains-voltage manipulation: European low-voltage directives (LVD 2014/35/EU) and EMC compliance may be voided after modification; recertification is needed for commercial use.
• Warranty and Tuya cloud T&C are broken once reflashed.
• Data privacy improves (local control, no cloud).
• Always disconnect from mains, use an isolating transformer for bench tests, and respect national electrical codes (NF C 15-100 in France).
Preparation
• Scan PCB for template in community DB – may spare you pin-hunting.
• Backup original firmware via bk_writer --dump.
OTA (Cloudcutter) procedure
• Phone in AP mode, feed device Internet, run exploit script.
• If exploit fails → fall back to UART.
Serial flashing quick-flow
a) 3 V3 ↔ VCC, GND ↔ GND, TX/RX cross.
b) Hold CEN low, power up, release → chip in boot loader.
c) ./uartprogram OpenBK7231*.bin -b 115200 -w.
First boot
• Connect to OpenBK_xxxxxx AP → 192.168.4.1 → Wi-Fi creds.
• Upgrade to newest build via Web-OTA.
Configuration
• Config → Configure Module → assign Diode_R_B_A/B.
• Optionally assign status LED (LED_i) and push-button (Button).
Validation
• Oscilloscope between pilot wire and Neutral: confirm correct half-wave.
• Swap GPIO roles if wrong polarity.
Integration
• Config → MQTT → broker, topic base.
• Enable setOption73 1 (HA auto-discover).
Common pitfalls & fixes
• Modes inverted → swap A/B roles.
• Relay chattering → wrong GPIO type, use “Relay (i)” not “PWM”.
• HA entity missing → retain flag off, then restart HA.
• Some heaters support 6-order pilot-wire (Comfort −1 °C / −2 °C). OpenBK night-builds already expose values 4 & 5; hardware must support triac phase gating.
• Very small Tuya modules (CB2S) use 2 mm pitch pads – soldering is delicate.
• OTA exploits may be patched in new Tuya firmware revisions; keep a USB-UART dongle handy.
• Evaluate open-source zero-cross AC wave-shaping libraries to add 6-order modes.
• Investigate Matter over Wi-Fi integration once the OpenBK Matter branch stabilises.
• Look at NRF24L01 pilot-wire bridges for multi-room synchronised heating as a complement to Wi-Fi.
• Monitor OpenBK GitHub issues: many templates for brand-new Legrand/Möhlenhoff pilot-wire relays appear weekly.
Flashing OpenBeken onto a Tuya pilot-wire module, assigning its two output pins to the built-in “Diode_R_B” driver, and mapping channel values 0-3 to Comfort/Eco/Frost/Off lets you reproduce the four canonical pilot-wire commands locally, cloud-free, and fully automatable via MQTT or HTTP. OTA flashing with CloudCutter now covers most BK7231 devices; serial flashing remains the universal fallback. Verify half-wave polarity, follow mains-safety rules, and you have a robust, open-source heating controller ready for seamless Home-Assistant integration.