esphome-ln882h-pwm

Hardware PWM output component for Lightning LN882H chips in ESPHome.

ESPHome's built-in libretiny_pwm component does not work on LN882H because analogWrite() is not implemented in LibreTiny for this chip. This component bypasses that limitation by directly using the LN882H SDK's Advanced Timer peripheral for true hardware PWM — no flicker, no workarounds.

Features

• True hardware PWM using the LN882H Advanced Timer peripheral
• Up to 6 simultaneous PWM channels (channels 0–5)
• Works on any GPIOA or GPIOB pin
• Configurable frequency (default 1 kHz)
• Compatible with ESPHome's light, fan, and output components
• Fully dimmable LED control via Home Assistant

Installation

Add this to your ESPHome YAML:

external_components:
  - source:
      type: git
      url: https://github.com/Nouxii/esphome-ln882h-pwm
    components: [ln882h_pwm]

Usage

Basic dimmable light

output:
  - platform: ln882h_pwm
    id: my_light_pwm
    port: 0           # 0 = GPIOA, 1 = GPIOB
    pin_num: 10        # Pin number within the port (e.g. 10 = GPIOA10)
    timer_channel: 0   # Advanced Timer channel (0–5)
    frequency: 1000    # PWM frequency in Hz

light:
  - platform: monochromatic
    name: "My Dimmable Light"
    output: my_light_pwm

RGBCW LED strip (5 channels)

output:
  - platform: ln882h_pwm
    id: pwm_red
    port: 0
    pin_num: 13
    timer_channel: 0
    frequency: 1000

  - platform: ln882h_pwm
    id: pwm_green
    port: 0
    pin_num: 14
    timer_channel: 1
    frequency: 1000

  - platform: ln882h_pwm
    id: pwm_blue
    port: 0
    pin_num: 15
    timer_channel: 2
    frequency: 1000

  - platform: ln882h_pwm
    id: pwm_cold_white
    port: 0
    pin_num: 9
    timer_channel: 3
    frequency: 1000

  - platform: ln882h_pwm
    id: pwm_warm_white
    port: 0
    pin_num: 12
    timer_channel: 4
    frequency: 1000

light:
  - platform: rgbww
    name: "LED Strip"
    red: pwm_red
    green: pwm_green
    blue: pwm_blue
    cold_white: pwm_cold_white
    warm_white: pwm_warm_white
    cold_white_color_temperature: 6500 K
    warm_white_color_temperature: 2700 K

Configuration

Parameter	Required	Default	Description
port	Yes	—	GPIO port: 0 for GPIOA, 1 for GPIOB
pin_num	Yes	—	Pin number within the port (0–15)
timer_channel	No	0	Advanced Timer channel (0–5). Each output needs its own channel.
frequency	No	1000	PWM frequency in Hz

Pin Reference

The LN882H QFN32 (LN882HKI) has 20 GPIOs across two ports. Here are the commonly used PWM-capable pins:

GPIO	ESPHome name	Port	Pin Num	QFN32 Pin	Notes
GPIOA7	PA7	0	7	15	PWM capable
GPIOA9	PA9	0	9	17	Also BOOT pin
GPIOA10	PA10	0	10	21	PWM capable
GPIOA11	PA11	0	11	22	PWM capable
GPIOA12	PA12	0	12	23	PWM capable
GPIOB3	PB3	1	3	24	PWM capable

Pins GPIOA13–GPIOB2 are reserved for QSPI flash and should not be used.

How It Works

The LN882H has 6 Advanced Timer channels, each capable of generating independent PWM signals. This component:

1. Enables the Advanced Timer clock gate
2. Configures the timer with the desired frequency using the APB0 clock
3. Maps the selected GPIO to the timer channel via the AFIO (Alternate Function I/O) multiplexer
4. Sets the duty cycle by adjusting the timer's compare register

The implementation is based on the PWM code from OpenBeken, adapted to work as a native ESPHome external component.

Background

This component was created because:

• The LN882H chip is increasingly used in Tuya WiFi devices as a replacement for BK7231/ESP modules
• ESPHome supports LN882H via LibreTiny, but libretiny_pwm fails to compile because analogWrite() is not implemented for this platform
• OpenBeken has working PWM for LN882H, proving the hardware supports it — the gap was only in the ESPHome/LibreTiny Arduino layer

Compatibility

• Tested on: LN882HKI (QFN32, 2MB flash)
• ESPHome: 2026.3.1+
• LibreTiny: v1.12.1+
• Board: generic-ln882hki

License

MIT

Credits

• PWM implementation based on OpenBeken's LN882H HAL
• LibreTiny for LN882H ESPHome platform support
• Elektroda.com community for LN882H documentation and teardowns