Govee 6in recessed RGBCCT light
Uses a custom module, similar to a WBR3. CPU is RTL8720CF.

Opening the light is relatively easy. First you have to pull the spring clips out of the body. Using pliers, pull each tab up and out of the main body; they can be rather stubborn to remove.
Next remove the four Phillips screws from the back of the case. At this point the front half (with the lens) will separate from the metal back case. The main PCB is retained in the metal case by two small metal tabs that extend through the PCB and are bent over to lock it in place. You may be able to leave the main PCB in the metal housing, but I found that I was unable to either solder or make reasonable contact with all the pads to program the module without releasing it from the housing. I did not have to desolder the main power leads, or remove the main power lead from its retainer; being able to tip the PCB up to gain better access to the control module was enough in my case.

To flash the module, you'll have to use ltchiptool. I found that I was unable to flash them at a baud rate other than 115200. I also found making a flash backup took ~30 minutes.
Govee was kind, and exposed all the connections you need to flash the module as test points along the outside of the module:
Flash Pinout
| Pin | Function |
|---|---|
| A-0 | Download Mode -> Pull High |
| TXD | Download Mode -> Pull High |
| 3V3 | 3.3V Supply |
| RX | Log UART TX -> RX Serial 2 USB |
| TX | Log UART RX -> TX Serial 2 USB |
| GND | Module Ground |
I did not have to use the CEN pin to reboot the module in download mode, instead I was able to connect A-0 and TXD to 3.3V before powering up the module.
GPIO Pinout
| Pin | Function |
|---|---|
| PA03 | Red Output |
| PA18 | Blue Output |
| PA02 | Green Output |
| PA19 | Cold White Output |
| PA04 | Warm White Output |
I found that after flashing with ESPHome, the lights, when set to 100%, were significantly brighter than the stock firmware. To try to limit the heat produced by the light, I set the max power for each of the LED PWM channels to 80%.
Basic Configuration
substitutions:
devicename: govee-recessed-light
esphome:
name: $devicename
rtl87xx:
board: generic-rtl8720cf-2mb-992k
# Enable logging
logger:
# Enable Home Assistant API
api:
ota:
wifi:
ssid: !secret wifi_ssid
password: !secret wifi_password
# Output pins
output:
- platform: libretiny_pwm
pin: PA02
id: green_pwm_output
max_power: 80%
- platform: libretiny_pwm
pin: PA03
id: red_pwm_output
max_power: 80%
- platform: libretiny_pwm
pin: PA18
id: blue_pwm_output
max_power: 80%
- platform: libretiny_pwm
pin: PA04
id: warm_pwm_output
max_power: 80%
- platform: libretiny_pwm
pin: PA19
id: cool_pwm_output
max_power: 80%
light:
- platform: rgbww
name: "Light"
red: red_pwm_output
green: green_pwm_output
blue: blue_pwm_output
cold_white: cool_pwm_output
warm_white: warm_pwm_output
cold_white_color_temperature: 6350 K
warm_white_color_temperature: 3000 K
color_interlock: True