ESP32-C3 Tuya CBU Replacement Module (ESP8685-WROOM-06)
ESP32-C3 Tuya CBU Replacement

Available from:


GPIO #Component
GPIO00 User
GPIO01 User
GPIO02 User
GPIO03 User
GPIO04 User
GPIO05 User
GPIO06 User
GPIO07 User
GPIO08 User
GPIO09 User
GPIO10 User
GPIO12 None
GPIO13 None
GPIO18 User
GPIO19 User
GPIO20 User
GPIO21 User
Configuration for ESP32-C3
This module can replace modules such as: AXYU, BPU, CBU, ZSU, ZTU, WBRU

ESP8685 is the new nomenclature for ESP32-C3 based modules. There are two different versions of this module:

  • ESP8685-WROOM-06-H4 with 4Mb flash
  • ESP8685-WROOM-06-H2 with 2Mb flash is not recommended for Tasmota due to low flash space.


Flash using Tasmota Web Installer and select Tasmota ESP32-C3 option.

For esptool.py download f.e. tasmota32c3.factory.bin and run esptool.py write_flash 0x0 tasmota32c3.factory.bin

To put ESP32-C3 in flash mode GPIO8 needs to be pulled high and GPIO9 pulled low.



For normal operation connect EN to VCC (pull high) to enable the chip. GPIO9 has an internal pullup and it needs to be high on power up for the module to boot so try and avoid that pin similar to GPIO0 on ESP8266.

ESP32’s are power hungry on boot and the USB to serial adapter might not be able to provide enough power for that. Use a stable 3.3v power supply that can supply more than 500 mA.