New-Tech Europe Magazine | Oct 2017 | Digital Edition

are “Hey AMB2621!”. The associated Received Signal Strength Indication (RSSI) value is 0xC8, i.e. -56 dBm.) If now the AMB2621 is to transmit data such as “Hey App!” to the smartphone, the host connected has to send the following data to AMB2621 via UART:

periodic transmission of temperature or other environmental data. Distance estimation of a transmitter by means of the RSSI value or position determination by triangulation of several beacons is also conceivable. Conclusion Instead of equipping a device with a display, making a smartphone fit for use as a user interface or developing a door control system with a mobile device – these are typical applications that should ideally be run independently of WLAN availability – here Bluetooth is a viable alternative. The wireless module introduced here makes integration especially easy. By the way, samples of AMB2621 and the associated evaluation board AMB2621-EV are available from stock. Field sales engineers are available on- site to provide support in the design- in process and also to elaborate specifications if customer-specific adaptation of the AMBER firmware stack is required. AMBER wireless AMB2621 FCC and CE certified BLE module Just 8x11x1.8 mm in size Nordic Semiconductor nRF52832 BLE chip 32 bit ARM Cortex-M4 CPU, 512 kB Flash memory Amber SPP-over-BLE profile Low power consumption (TX 5.3mA@0dBm, RX 5.4mA, sleep 0.4µA) Ideal for expanding battery-operated systems with a BLE interface

that these data are transmitted to the smartphone connected. BLE possibilities fully exploited With the Peripheral Only mode, Amber wireless uses a typical function in mobile communications applications for industrial purposes. In another place, the manufacturer purposefully moves away from the common standards. For wireless, AMB2621 offers the “AMBER-SPP-like” profile, which allows transmission of general data between the two connection partners. The Bluetooth Serial Port Profile (SPP) does not actually exist anymore for BLE, which is why AMBER wireless offers its own solution here. Here the optional Bluetooth 4.2 feature “data length extension” (DLE) is used, such that payload sizes up to 243 bytes per Bluetooth packet are possible with the AMB2621. This raises throughput up to 5 kB/s. Familiar pairing methods like JustWorks or StaticPasskey are made available in order to ensure stable data transmission. In the case of StaticPasskey, a 6-digit key has to be entered on a terminal device

such that a secure connection can be established. The bonding function, i.e. the use of keys already used for re-authentication, is available in AMB2621. Further application options In many cases, the decision between command control of the chip and the Peripheral mode is clearly prescribed by the requirements of the application. However, it is also possible to provide the otherwise firmly soldered pins with a switch for mode selection. This can be useful if the wireless module is normally used for the data request initiated by the mobile device, but is occasionally opened by the device for more complex communication tasks, such as maintenance or configuration tasks. The module is also capable of all other Bluetooth modes. Broadcasting for example: In place of connection- oriented data transmission, so-called beacons are used to emit power- saving data – the module “sleeps” when it does not transmit. This function is well-suited for battery- operated sensor applications like the

AMB2621 is a 2.4-GHz-BLE wireless module compliant with the Bluetooth-Smart-4.2 standard.

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