Explain Bluegiga APX4 protocol.
It's no surprise that this one pops up often in IoT interview questions for experienced candidates. The Bluegiga APx4 is a wireless System-on-Module that has a low power consumption (SOM). Since it has built-in Wi-Fi, Bluetooth 4.0, ARM, and Linux, this development platform is perfect for building gateways since it has all of these features incorporated. Because they are consistent with coexistence rules, wireless and Bluetooth low energy (BLE) may be used together without causing interference to any technology. Wi-Fi and Bluetooth connectivity are also supported by the Bluegiga Apx4, and the device's 450 MHz Arm9 CPU ensures a fluid user experience.