ESPHome BP5926 Light Component

Custom ESPHome external component for LED fixtures using the BP5926A (Bright Power / 晶丰明源) dual-channel CW/WW PWM color-mixing driver IC.

The Problem

The BP5926A uses a single PWM input to control the cold/warm white ratio, with a separate MOSFET controlling white LED power. Standard ESPHome light platforms (rgbww, cwww) can't drive this hardware correctly because they:

1. Couple brightness to both channels — dimming changes the color temperature
2. Zero the power pin at warm color temps — the light turns off instead of going warm
3. Invert the color mapping — the slider shows the opposite of what the fixture produces

The Solution

This component properly decouples brightness from color temperature:

• White power pin always tracks brightness (never zeroed by color temp changes)
• Color temp ratio pin independently controls the BP5926's CW/WW ratio (never scaled by brightness)
• RGB channels provide supplemental cool-toned light, scaling with both color temp and brightness
• Exposes native color_temp + rgb modes to Home Assistant

Known Compatible Hardware

Device	Module	Board	Notes
Feit Electric LEDR6/RGBW/AG	CBU (BK7231N)	ED-05-B2002-V09	Cloud-cut via CloudCutter

Feit LEDR6 CBU Pin Map

Pin	Function
P26	Red LED (MOSFET)
P24	Green LED (MOSFET)
P6	Blue LED (MOSFET)
P8	White LED power — must always track brightness
P7	BP5926 Pin 6 — CW/WW ratio (100% = cold, 0% = warm)

Installation

Add to your ESPHome YAML:

external_components:
  - source:
      type: git
      url: https://github.com/trbom5c/esphome-bp5926
    components: [bp5926]

Usage

output:
  - platform: libretiny_pwm
    id: output_red
    pin: P26
    frequency: 3000 Hz

  - platform: libretiny_pwm
    id: output_green
    pin: P24
    frequency: 3000 Hz

  - platform: libretiny_pwm
    id: output_blue
    pin: P6
    frequency: 3000 Hz

  - platform: libretiny_pwm
    id: output_white_power
    pin: P8
    frequency: 3000 Hz

  - platform: libretiny_pwm
    id: output_color_temp_ratio
    pin: P7
    frequency: 3000 Hz

light:
  - platform: bp5926
    name: "Light"
    red: output_red
    green: output_green
    blue: output_blue
    white_power: output_white_power
    color_temp_ratio: output_color_temp_ratio
    restore_mode: RESTORE_DEFAULT_ON

Configuration Variables

Variable	Required	Description
red	Yes	Red LED PWM output
green	Yes	Green LED PWM output
blue	Yes	Blue LED PWM output
white_power	Yes	White LED power output (brightness control)
color_temp_ratio	Yes	BP5926 PWM input (color temperature ratio)
name	Yes	Light entity name
restore_mode	No	Default: ALWAYS_OFF. Use RESTORE_DEFAULT_ON for lights that should restore state on power loss

How It Works

Color Temperature Mode

• P8 (white_power) = overall brightness
• P7 (color_temp_ratio) = color temperature mapped to 0.0–1.0 (warm–cold)
• RGB = supplemental cool-toned tint, scales linearly with color temp ratio and brightness

RGB Mode

• RGB = direct color control
• P8, P7 = off (white LEDs disabled)

BP5926A IC Details

• Package: SOP-8
• Function: Dual-channel constant-current LED driver with built-in MOSFETs
• Input: Single PWM signal (3.3V/5V, up to 10kHz)
• Output: Two LED channels with ratio controlled by PWM duty cycle
• Built-in MOSFETs: 100V, 0.6Ω RDS(ON), ~700mA max per channel

License

MIT License — see LICENSE.