Experiment with the Adafruit Circuit Playground Bluefruit featuring a powerful Nordic Semiconductor nRF52840 ARM Cortex M4 microcontroller. Explore embedded programming with CircuitPython, Arduino, ARM GCC, and more. Control embedded programs from mobile devices over Bluetooth Low Energy (BLE) channels. Use the Playground Ghost PCB to breadboard with the Circuit Playground Bluefruit. Understand and implement voltage divider circuits, class D audio amplifiers, full color LCD displays, and extra storage using both SD memory cards and serial flash chips.