This adapter board simplifies the integration of classic Bluetooth modules like HC-05, HC-06, HC-07, and BC04 into 5 V microcontroller systems. It includes a 3.3 V regulator and level-shifting circuitry, making it plug-and-play for Arduino, ESP32, and STM32 boards.

Specifications

• Compatibility: HC-05, HC-06, HC-07, BC04 (classic Bluetooth modules)
• Voltage Input: 3.6 V–6 V (typ. 5 V)
• Logic Level: 3.3 V (safe for 5 V MCU RX via onboard divider)
• Regulator: AMS1117 3.3 V LDO
• Interface: UART (TXD, RXD)
• Breakout Pins:
  - VCC, GND
  - TXD, RXD
  - STATE (connection status)
  - EN (key pin for AT mode)
• LED Indicators:
  - Power LED
  - Status LED (blinking/connected)
• Mounting: Breadboard-friendly pin headers
• Dimensions: ~43 mm × 15 mm
• PCB Color: Varies (typically blue or red)

Features

• Simplifies wiring and voltage compatibility for Bluetooth modules
• Onboard 3.3 V regulator for safe module operation
• Plug-and-play with Arduino, ESP32, STM32, and other 5 V systems
• Ideal for DIY wireless serial communication setups
• Common use cases:
  - Bluetooth-controlled Arduino projects
  - Wireless sensor data transmission
  - Serial bridges and automation systems
  - Classroom and STEM Bluetooth experiments