Bluetooth is a great addition to a variety of projects, but the interface to most Bluetooth modules is through a serial UART, which can be a real bummer -- serial port availability can be limited and they're not always super-reliable. The Qwiic Bluetooth aims resolve that issue by providing an I²C interface to the HM-13 Bluetooth module.

This board's HM-13 Bluetooth module supports both SPP (Serial Port Profile) and BLE (Bluetooth low-energy) Bluetooth profiles via Bluetooth 4.0. The HM-13's support for BLE means it's compatible with any smartphone. Or you can connect it to a computer via the old standard -- SPP -- and use it as a transparent Bluetooth data gateway. You can even use it in dual-mode, connected to a pair of devices simultaneously!

The board also features an ATtiny85, which has custom firmware to translate between between I²C and serial. There are a pair of Qwiic connectors, which allow you to string a variety of sensors up to a single I²C bus. Finally, a green "CON" LED indicates connection status -- blinking when disconnected and solid when connected.

Check out our HM-13 Arduino library for help developing a Bluetooth app of your own! There are a handful of "Qwiic" examples, which demonstrate how to set up a simple serial passthrough, adjust some of the module settings, and even set it up as an iBeacon.

NOTE: The I²C address of the HM-13 is 0x1B and is jumper selectable to 0x1C (software-configurable to any address). A multiplexer/Mux is required to communicate to multiple HM-13 sensors on a single bus. If you need to use more than one HM-13 sensor consider using the Qwiic Mux Breakout.

• I²C translation for serial-based HM-13 module
• 2 Qwiic connectors
• Pre-programmed ATTiny85 translates serial streams
• Arduino library with full support for AT command set
• BLE and SPP Bluetooth profile support
• Built-in antenna
• v321 firmware
• 1.0 x 1.0"

• Datasheet
• Schematic
• Eagle Files
• Arduino Library
• GitHub Repository