Many consumers are now using this opportunity to replace their light bulbs to take the next step towards the smart home, and are picking up an LED bulb with a wireless chip that they can control with their smartphone. Following the well-known manufacturers, almost all other manufacturers now offer such LED retrofit solutions with ZigBee, Bluetooth, or WiFi. This is because an LED needs to have voltage rectification and conversion in the lamp socket anyway, and this voltage can also be used for a small wireless chip. This has consequences for manufacturers of other smart home devices.
Today, lamps are also operated by virtual assistants such as Alexa, Siri, Cortana, or Google Assistant, as well as smoke detectors, alarm clocks, and surveillance cameras. This usually takes place via the manufacturer’s own cloud and a ZigBee WLAN gateway or directly via Wi-Fi.
Recently, however, the Thread protocol has also been included in an increasing number of smart home applications. This is because it offers many advantages over proprietary addressing systems that are limited to the local network. So if a radio alarm clock should be able to control not only the light but also the roller shutters or the coffee machine in the future, for example, it must also include Thread integration in addition to ZigBee.
Bluetooth 5 also comes with several operating modes that make it interesting for smart home devices. In addition, it is already available in current smartphones – unlike ZigBee and Thread. The Bluetooth Mesh 1.0 protocol can even be used starting with Bluetooth 4.0 and supports the operation of large networks, i.e. many smart home devices.
But a really good radio alarm clock will not only switch on the music and the lights. It will also detect your pulse and movements, and increase the volume and light gently and in a controlled manner during the right sleep stage. To do so, it needs access to your smartwatch or fitness tracker, which are mainly equipped with the ANT protocol.
That means that the radio alarm clock should have ZigBee, Thread, Bluetooth 5, Bluetooth Mesh and ANT in order to communicate with any smart home device.
Another wireless standard helps prevent consumers from having to set up all these connections to all their smart home devices and systems individually: Near Field Communication (NFC). Thanks to NFC, you can set up all the networks completely automatically by simply tapping the smart home device – in our example the radio alarm clock – with a smartphone.
The nRF52840 from Nordic Semiconductor can handle all of these protocols, and it also comes with a USB interface, AD converter, and various security tools – and is hardly more expensive than a solution that only uses ZigBee. If you would like to try out the nRF52840-Dongle, you can purchase a small development kit for less than ten euros. In addition, the Segger compiler and a GNU compiler are available for free, or, as an alternative, versions of IAR or Keil can be used with the nRF52840, subject to certain limitations. And for anyone who is really on board with it, the nRF52840 Development Kit provides a more powerful development environment.