By Würth Elektronik EISOS 85
Wurth Electronics' Bluetooth® Smart (previously called Bluetooth Low Energy) technology is a part of the Bluetooth Core Specification from Bluetooth v4.0 onwards. Bluetooth Smart brings Bluetooth wireless connectivity to low cost, small, battery-operated devices that require months or even years of battery lifetime. Therefore, Bluetooth Smart enables a new and extended range of applications, including watches, proximity tags, sports and fitness sensors, healthcare sensors, and remote controls, to benefit from Bluetooth wireless technology.
Key features of Bluetooth Smart include:
Bluetooth Smart has official support in iOS and Android mobile platforms as well as most desktop platforms including OSX, Windows 8 or higher, and Linux
The AMB2621 is an ultra-low power 2.4 GHz wireless module integrating the nRF52832 system-on-chip (SoC) including a 2.4 GHz transceiver and an Arm® Cortex®-M4F CPU with Flash memory. The module is optimized for applications where costs and low-power optimization matter.
Several pins with alternate functions are available to connect LEDs or realize an SPI, I2C, ADC, or handshake for the UART, for example, as well as NFC (near field communication).
In its delivery state, the module comes with a Wurth Electronics firmware according to option 1.
By default, the module provides the industry-proven, fully qualified Bluetooth Smart stack from Nordic plus the Wurth Electronics firmware. The latter contains an SPP-like profile, which offers a fast, secured data transmission of small packets with up to 128 bytes payload. Furthermore, the AMB2621 includes an easy-to-use command interface allowing a convenient configuration and operation.
The module can perform both an advertising state in order to be found or a scan for finding other devices that are advertising. Data transmission can be executed as soon as a (secured) connection has been set up.
In addition, data can be broadcast quickly using so-called Beacons. The module enables distance estimation (localization) using RSSI and output power in one advertise packet for optimized power consumption.
As an interface to the host system, a 2-wire UART interface is provided with a default data rate of 115,200 Baud. OTA firmware update via PC or Android/iOS app is supported. An Android app supporting the SPP-like operation is also available on request.
The AMB2621 firmware (version 3.0.0 or newer) provides the peripheral only operation mode that allows the easy adaption of already existing custom hardware with the BLE interface. By default, this mode offers the static passkey pairing method and a transparent UART interface. With this, custom hardware can be accessed by mobile BLE devices (like smartphones including a custom app) using an authenticated and encrypted BLE link without the need of configuring the module.
Based on the Nordic Semiconductor SDK and demo examples various BLE-profiles and custom applications can be realized and flashed on the AMB2621 module. The versatile and well documented Nordic stack ensures the quick and easy realization of various standard BLE-profiles, such as:
Bluetooth Toolbox: AMBER provides an app as a .apk file for registered users that can be installed on any smartphone with built-in Bluetooth Smart hardware using Android versions 4.3 or newer (API level 18 or newer).