The Bluefruit LE SPI Friend adds Bluetooth Low Energy to any microcontroller using 4–5 GPIO pins via SPI, with iOS/Android app support, Nordic UART service, AT commands for custom GATT control, and OTA firmware updates.
The Adafruit Bluefruit LE SPI Friend makes it simple to add Bluetooth® Low Energy to robots, art projects and other electronics using just 4 or 5 GPIO pins. It connects over SPI (MISO, MOSI, SCK and CS) with an optional 5th interrupt pin, so you don’t have to deal with baud rates, flow control, or giving up a hardware UART.
Most users will use the Nordic UART RX/TX service, where the Bluefruit acts as a transparent data pipe between your microcontroller and an iOS or Android device. You can communicate using Adafruit’s free iOS and Android apps, or write your own app to talk to the UART service. If you’d rather use serial than SPI, there’s also a UART version available.
The module also supports an AT command set for deeper control, including creating and editing your own GATT services and characteristics, changing advertising behaviour, and reading details such as die temperature, battery voltage, RSSI and MAC address. The Bluefruit can also be configured to act as an HID keyboard, a Bluetooth LE heart rate monitor (with added pulse-detection circuitry), or a UriBeacon that broadcasts a URL. It also includes over-the-air bootloading, allowing firmware updates directly from an Android or iOS device.
One of the key advantages of the Bluefruit LE family is that Adafruit wrote and maintains the firmware themselves, so updates and features aren’t dependent on third-party vendors.
Features
ARM Cortex M0 core running at 16MHz
256KB flash memory
32KB SRAM
Transport: SPI at up to 4MHz clock speed
5V-safe inputs (Arduino Uno friendly, etc.)
On-board 3.3V voltage regulation
Bootloader with support for safe OTA firmware updates
Easy AT command set tunnelled over SPI protocol to get up and running quickly
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